Pub Date : 1982-07-01DOI: 10.3181/00379727-170-41436
D R Garris, R Rodway, G Gibori
Abstract The ability of estradiol (E) and progesterone (P) to act as luteotrophins in place of LH was investigated in pseudopregnant (PSP) rats. The length of PSP was extended by either hysterectomy (hyst.) or by the experimental induction of decidual tissue (DT) on Day 5 (Day 1 = ovulation). On Day 9, LH was removed from circulation by a sc injection of a specific LH antiserum (LHAS) and each rat was simultaneously treated with various dosages of E and/or P. Control rats were treated with normal horse serum (NHS) and/or oil vehicle. Blood samples were collected at 0, 24, and 72 hr post-treatment for the estimation of serum P levels. Day 5 hyst. rats treated with any dose (0.1 − 10.0 μg) of E or P (2 mg), alone or in combination, and simultaneously injected with NHS or LHAS exhibited elevated P levels through Day 12 and an extended diestrous cycle. In contrast, oil-treated, LHAS-injected rats underwent immediate luteolysis. DT-bearing PSP rats treated with 10 μg of E failed to undergo luteolysis following LHAS treatment; however, neither the lower E dosages nor P were able to prevent corpus luteum regression in these rats. The placement of estradiol (5 μg) pellets under the ovarian bursa maintained luteal function in both hyst. and DT-bearing PSP rats after the Day 9 LHAS injection. To determine if E prevented or merely delayed LH-dependent P secretion, 10.0 μg of E was administered on Day 9 and LHAS injected on Day 12. The E treatment effectively overrode the requirement for LH in the hyst.-PSP rat. In contrast, the DT-bearing PSP animals underwent luteolysis following the Day 12 LHAS treatment. NHS injections had no effect on luteal function. The results of these studies suggest that both E and P can serve as direct luteotrophins, replacing the requirement for LH by the rat corpus luteum. Higher doses of E are necessary in DT-bearing PSP rats than in hyst. animals to maintain luteal function. Also, while E eliminates the need for LH in the hyst.-PSP rat, it merely delays the luteal dependency on LH in the DT-bearing rat.
{"title":"Effects of ovarian steroids on luteal function: prevention of luteolysis following LH-neutralization in the pseudopregnant rat.","authors":"D R Garris, R Rodway, G Gibori","doi":"10.3181/00379727-170-41436","DOIUrl":"https://doi.org/10.3181/00379727-170-41436","url":null,"abstract":"Abstract The ability of estradiol (E) and progesterone (P) to act as luteotrophins in place of LH was investigated in pseudopregnant (PSP) rats. The length of PSP was extended by either hysterectomy (hyst.) or by the experimental induction of decidual tissue (DT) on Day 5 (Day 1 = ovulation). On Day 9, LH was removed from circulation by a sc injection of a specific LH antiserum (LHAS) and each rat was simultaneously treated with various dosages of E and/or P. Control rats were treated with normal horse serum (NHS) and/or oil vehicle. Blood samples were collected at 0, 24, and 72 hr post-treatment for the estimation of serum P levels. Day 5 hyst. rats treated with any dose (0.1 − 10.0 μg) of E or P (2 mg), alone or in combination, and simultaneously injected with NHS or LHAS exhibited elevated P levels through Day 12 and an extended diestrous cycle. In contrast, oil-treated, LHAS-injected rats underwent immediate luteolysis. DT-bearing PSP rats treated with 10 μg of E failed to undergo luteolysis following LHAS treatment; however, neither the lower E dosages nor P were able to prevent corpus luteum regression in these rats. The placement of estradiol (5 μg) pellets under the ovarian bursa maintained luteal function in both hyst. and DT-bearing PSP rats after the Day 9 LHAS injection. To determine if E prevented or merely delayed LH-dependent P secretion, 10.0 μg of E was administered on Day 9 and LHAS injected on Day 12. The E treatment effectively overrode the requirement for LH in the hyst.-PSP rat. In contrast, the DT-bearing PSP animals underwent luteolysis following the Day 12 LHAS treatment. NHS injections had no effect on luteal function. The results of these studies suggest that both E and P can serve as direct luteotrophins, replacing the requirement for LH by the rat corpus luteum. Higher doses of E are necessary in DT-bearing PSP rats than in hyst. animals to maintain luteal function. Also, while E eliminates the need for LH in the hyst.-PSP rat, it merely delays the luteal dependency on LH in the DT-bearing rat.","PeriodicalId":20675,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine","volume":" ","pages":"313-20"},"PeriodicalIF":0.0,"publicationDate":"1982-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3181/00379727-170-41436","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35262366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1982-07-01DOI: 10.3181/00379727-170-41444
J K Manning, M Drewes-Prochniak
Abstract It is generally considered that the induction of IgE antibody responses in laboratory animals to parenterally injected antigens requires the simultaneous administration of an adjuvant such as Al(OH)3 gel or Bordetella pertussis vaccine. In this study, we have been able to induce IgE antibody formation in mice to antigens such as heterologous whole serum or ovalbumin by giving multiple intraperitoneal injections of these substances without any added adjuvant. The IgE responses were measured by the passive cutaneous anaphylaxis (PCA) test performed in rats. The abrogation of PCA activity by heat treatment of undiluted serum for one hour at 56 ° was confirmed. We propose that this represents an ideal model to study induction of IgE antibody formation.
{"title":"IgE antibody responses induced by repeated administration of antigens without adjuvant.","authors":"J K Manning, M Drewes-Prochniak","doi":"10.3181/00379727-170-41444","DOIUrl":"https://doi.org/10.3181/00379727-170-41444","url":null,"abstract":"Abstract It is generally considered that the induction of IgE antibody responses in laboratory animals to parenterally injected antigens requires the simultaneous administration of an adjuvant such as Al(OH)3 gel or Bordetella pertussis vaccine. In this study, we have been able to induce IgE antibody formation in mice to antigens such as heterologous whole serum or ovalbumin by giving multiple intraperitoneal injections of these substances without any added adjuvant. The IgE responses were measured by the passive cutaneous anaphylaxis (PCA) test performed in rats. The abrogation of PCA activity by heat treatment of undiluted serum for one hour at 56 ° was confirmed. We propose that this represents an ideal model to study induction of IgE antibody formation.","PeriodicalId":20675,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine","volume":" ","pages":"367-72"},"PeriodicalIF":0.0,"publicationDate":"1982-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3181/00379727-170-41444","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35262369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1982-07-01DOI: 10.3181/00379727-170-41431
D M Reinitz, M J Paape, I H Mather
Abstract Polymorphonuclear leukocytes (PMN) were isolated from bovine blood or milk and incubated with heat-killed yeast stained with pH indicator dyes. Observation of changes in the color of the phagocytosed yeast allowed a determination of the temporal and maximal depression in the pH of the newly formed phagosomes. Results indicated that the maximal depression of pH was to approximately 5.0 for PMN isolated from both sources, although cells from milk produced fewer (P < 0.01) phagosomes reaching pH 5.0 than cells from blood. The effect of casein or milk fat globules on the temporal depression in pH of phagosomes was determined by preincubating PMN from blood with isolated preparations of casein and milk fat globules. Results indicated that the prior ingestion of fat globules by PMN inhibited the subsequent depression of pH within phagosomes compared with untreated control cells (P < 0.05). Ingestion of casein micelles, however, had no effect (P > 0.05). The results are discussed with reference to previous reports that PMN in milk have reduced phagocytic ability and bactericidal properties compared with PMN in the systemic circulation.
{"title":"Effect of phagocytosed fat and casein on the intraphagosomal pH in bovine polymorphonuclear leukocytes.","authors":"D M Reinitz, M J Paape, I H Mather","doi":"10.3181/00379727-170-41431","DOIUrl":"https://doi.org/10.3181/00379727-170-41431","url":null,"abstract":"Abstract Polymorphonuclear leukocytes (PMN) were isolated from bovine blood or milk and incubated with heat-killed yeast stained with pH indicator dyes. Observation of changes in the color of the phagocytosed yeast allowed a determination of the temporal and maximal depression in the pH of the newly formed phagosomes. Results indicated that the maximal depression of pH was to approximately 5.0 for PMN isolated from both sources, although cells from milk produced fewer (P < 0.01) phagosomes reaching pH 5.0 than cells from blood. The effect of casein or milk fat globules on the temporal depression in pH of phagosomes was determined by preincubating PMN from blood with isolated preparations of casein and milk fat globules. Results indicated that the prior ingestion of fat globules by PMN inhibited the subsequent depression of pH within phagosomes compared with untreated control cells (P < 0.05). Ingestion of casein micelles, however, had no effect (P > 0.05). The results are discussed with reference to previous reports that PMN in milk have reduced phagocytic ability and bactericidal properties compared with PMN in the systemic circulation.","PeriodicalId":20675,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine","volume":" ","pages":"281-5"},"PeriodicalIF":0.0,"publicationDate":"1982-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3181/00379727-170-41431","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35262363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1982-07-01DOI: 10.3181/00379727-170-41430
B Braverman, A D Ivankovich, G Shah
{"title":"Thiosulfate pharmacokinetics in normal and anuric dogs.","authors":"B Braverman, A D Ivankovich, G Shah","doi":"10.3181/00379727-170-41430","DOIUrl":"https://doi.org/10.3181/00379727-170-41430","url":null,"abstract":"","PeriodicalId":20675,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine","volume":" ","pages":"273-80"},"PeriodicalIF":0.0,"publicationDate":"1982-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3181/00379727-170-41430","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35262362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1982-07-01DOI: 10.3181/00379727-170-41445
C Icard-Liepkalns, A Macieira-Coelho
Abstract Alkali-labile sites accumulate in DNA during aging in vitro of human embryonic lung fibroblasts. The sedimentation velocity of newly synthesized DNA was analyzed in alkaline sucrose gradients in young and old cells. Although most of the old cells had gone through a whole S period, their DNA sedimented in a dispersed fashion. Hydrocortisone shortened the time of appearance of bulk DNA. The results are compatible with the slowdown of DNA chain elongation during aging and could explain to a certain extent the sustaining effect of hydrocortisone on the human fibroblast lifespan.
{"title":"Aging and hydrocortisone effects on transient structures of replicative DNA of human fibroblasts.","authors":"C Icard-Liepkalns, A Macieira-Coelho","doi":"10.3181/00379727-170-41445","DOIUrl":"https://doi.org/10.3181/00379727-170-41445","url":null,"abstract":"Abstract Alkali-labile sites accumulate in DNA during aging in vitro of human embryonic lung fibroblasts. The sedimentation velocity of newly synthesized DNA was analyzed in alkaline sucrose gradients in young and old cells. Although most of the old cells had gone through a whole S period, their DNA sedimented in a dispersed fashion. Hydrocortisone shortened the time of appearance of bulk DNA. The results are compatible with the slowdown of DNA chain elongation during aging and could explain to a certain extent the sustaining effect of hydrocortisone on the human fibroblast lifespan.","PeriodicalId":20675,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine","volume":" ","pages":"373-7"},"PeriodicalIF":0.0,"publicationDate":"1982-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3181/00379727-170-41445","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35262370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1982-07-01DOI: 10.3181/00379727-170-41433
J A Georgiades, J Montgomery, T K Hughes, D Jensen, S Baron
Abstract There is no established prophylaxis of Herpes neonatorum. In experimental, newborn animals protection can be achieved by sufficient passive antibody given shortly after infection. Animal model data was sought to estimate a realistic and practical dose of human immune globulin for prophylaxis of newborn humans at risk. We used a neonatal mouse model and type II herpes simplex virus (HSV) to evaluate factors which govern the efficiency of antibody prophylaxis. Antibodies prepared in mice, rabbits, or man were equally protective. Timing experiments showed that these antibodies gradually lose their protective effect when administered more than 12 hr after infection. The first dose of multiple doses of antibody is the most crucial for protection. Intraperitoneal or subcutaneous injections of human immune globulin were equally effective. About 65 units of human anti-HSV antibody in 1-g newborn mice was the minimum dose which resulted in maximum protection. Comparison of this minimum protective dose with levels of neutralizing antibody in commercial immune globulin indicated that approximately 100 ml would be needed to achieve similar protective serum antibody levels in man. Six percent of potential blood donors were determined to have sufficient HSV antibody titers (≤1000 units) to prepare hyperimmune globulin at least 10 times more potent than commercially available immune globulin. Only 10 ml or less of such hyperimmune globulin is estimated to be protective. This reduced volume of hyperimmune globulin is easily injected into the loose subcutaneous tissue in the backs of newborn children.
{"title":"Determinants of protection by human immune globulin against experimental herpes neonatorum.","authors":"J A Georgiades, J Montgomery, T K Hughes, D Jensen, S Baron","doi":"10.3181/00379727-170-41433","DOIUrl":"https://doi.org/10.3181/00379727-170-41433","url":null,"abstract":"Abstract There is no established prophylaxis of Herpes neonatorum. In experimental, newborn animals protection can be achieved by sufficient passive antibody given shortly after infection. Animal model data was sought to estimate a realistic and practical dose of human immune globulin for prophylaxis of newborn humans at risk. We used a neonatal mouse model and type II herpes simplex virus (HSV) to evaluate factors which govern the efficiency of antibody prophylaxis. Antibodies prepared in mice, rabbits, or man were equally protective. Timing experiments showed that these antibodies gradually lose their protective effect when administered more than 12 hr after infection. The first dose of multiple doses of antibody is the most crucial for protection. Intraperitoneal or subcutaneous injections of human immune globulin were equally effective. About 65 units of human anti-HSV antibody in 1-g newborn mice was the minimum dose which resulted in maximum protection. Comparison of this minimum protective dose with levels of neutralizing antibody in commercial immune globulin indicated that approximately 100 ml would be needed to achieve similar protective serum antibody levels in man. Six percent of potential blood donors were determined to have sufficient HSV antibody titers (≤1000 units) to prepare hyperimmune globulin at least 10 times more potent than commercially available immune globulin. Only 10 ml or less of such hyperimmune globulin is estimated to be protective. This reduced volume of hyperimmune globulin is easily injected into the loose subcutaneous tissue in the backs of newborn children.","PeriodicalId":20675,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine","volume":" ","pages":"291-7"},"PeriodicalIF":0.0,"publicationDate":"1982-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3181/00379727-170-41433","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35262364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1982-07-01DOI: 10.3181/00379727-170-41435
C J Vanderwiel, R V Talmage, C W Cooper
Abstract This study examined physiological and bone morphological changes resulting from parathyroidectomy (PTX) in male rats. Two diets were provided: one contained 1.2% calcium, 1% phosphorus; the other 0.4-0.6% calcium, 0.6% phosphorus. However, at 51/2 months post-PTX all rats were transferred to a diet containing 0.3% calcium. The daily ration for each rat was 16 g. The parameters examined were: (1) Plasma calcium concentrations; (2) plasma and thyroidal calcitonin levels; and (3) histomorphometry of metaphyseal trabecular bone. When maintained on the lower calcium diet, fasted plasma calcium concentrations of PTX rats stabilized between 5 and 6 mg/dl. In contrast, in rats fed the higher calcium diet, these values gradually rose to between 7 and 8 mg/dl (5 months post-PTX). After transfer to the 0.3% calcium diet, plasma calcium values fell to >6 mg/dl. Thyroidal calcitonin content following PTX rose to values three times those of age-matched controls regardless of the daily calcium intake. The volume of trabecular bone in the tibial metaphysis increased threefold by 61/2 months after PTX; however, there was a decrease in osteoid on these bone surfaces. The static parameters of bone resorption and formation in PTX rats were not statistically different from controls; however, the ratio of osteoblasts to lining cells on trabecular surfaces increased following PTX. The cause of the increase in thyroidal calcitonin following PTX is as yet unknown, but appears to be unrelated to the changes in plasma calcium in rats fed a high calcium diet. This rise in plasma calcium is attributed to accumulation of calcium in the bone surface exchangeable compartment which is reversible. The increase in volume of trabecular bone may be due to slight changes in rates of bone turnover which are not detectable in analysis of static parameters. There was no evidence that the epiphyseal growth plate, or the rate of enchondral bone formation was affected by PTX. The effect of high dietary calcium on post-PTX plasma calcium values points out the need for close control of calcium content of rat chow if the rat is to be used as a model for studying calcium homeostasis or hormonal effects on bone remodeling.
{"title":"Plasma calcium, plasma and thyroidal calcitonin, and histomorphometric bone changes in parathyroidectomized rats.","authors":"C J Vanderwiel, R V Talmage, C W Cooper","doi":"10.3181/00379727-170-41435","DOIUrl":"https://doi.org/10.3181/00379727-170-41435","url":null,"abstract":"Abstract This study examined physiological and bone morphological changes resulting from parathyroidectomy (PTX) in male rats. Two diets were provided: one contained 1.2% calcium, 1% phosphorus; the other 0.4-0.6% calcium, 0.6% phosphorus. However, at 51/2 months post-PTX all rats were transferred to a diet containing 0.3% calcium. The daily ration for each rat was 16 g. The parameters examined were: (1) Plasma calcium concentrations; (2) plasma and thyroidal calcitonin levels; and (3) histomorphometry of metaphyseal trabecular bone. When maintained on the lower calcium diet, fasted plasma calcium concentrations of PTX rats stabilized between 5 and 6 mg/dl. In contrast, in rats fed the higher calcium diet, these values gradually rose to between 7 and 8 mg/dl (5 months post-PTX). After transfer to the 0.3% calcium diet, plasma calcium values fell to >6 mg/dl. Thyroidal calcitonin content following PTX rose to values three times those of age-matched controls regardless of the daily calcium intake. The volume of trabecular bone in the tibial metaphysis increased threefold by 61/2 months after PTX; however, there was a decrease in osteoid on these bone surfaces. The static parameters of bone resorption and formation in PTX rats were not statistically different from controls; however, the ratio of osteoblasts to lining cells on trabecular surfaces increased following PTX. The cause of the increase in thyroidal calcitonin following PTX is as yet unknown, but appears to be unrelated to the changes in plasma calcium in rats fed a high calcium diet. This rise in plasma calcium is attributed to accumulation of calcium in the bone surface exchangeable compartment which is reversible. The increase in volume of trabecular bone may be due to slight changes in rates of bone turnover which are not detectable in analysis of static parameters. There was no evidence that the epiphyseal growth plate, or the rate of enchondral bone formation was affected by PTX. The effect of high dietary calcium on post-PTX plasma calcium values points out the need for close control of calcium content of rat chow if the rat is to be used as a model for studying calcium homeostasis or hormonal effects on bone remodeling.","PeriodicalId":20675,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine","volume":" ","pages":"305-12"},"PeriodicalIF":0.0,"publicationDate":"1982-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3181/00379727-170-41435","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35262365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1982-07-01DOI: 10.3181/00379727-170-41442
L N Shulman, S H Robinson
Abstract Multinucleated giant cells (MNGCs) form spontaneously in long-term in vivo diffusion chamber cultures of murine bone marrow. Their appearance coincides with the growth of macrophages which become the predominant cells in culture after an initial phase favoring granulopoiesis. Host mice bearing diffusion chamber cultures were given regular injections of [3H]thymidine beginning prior to the development of MNGCs. The nuclei in MNGCs in these cultures were nonuniformly labeled. In any given MNGC all, none, or some of the nuclei might be labeled and the percentage of labeled nuclei was similar to the percentage labeling of the mononuclear macrophages in these cultures. These findings demonstrate that under these experimental conditions MNGCs arise primarily from cell fusion rather than nuclear division and that they are the random fusion products of both quiescent and actively dividing macrophages.
{"title":"Origin of multinucleated giant cells in long-term diffusion chamber cultures.","authors":"L N Shulman, S H Robinson","doi":"10.3181/00379727-170-41442","DOIUrl":"https://doi.org/10.3181/00379727-170-41442","url":null,"abstract":"Abstract Multinucleated giant cells (MNGCs) form spontaneously in long-term in vivo diffusion chamber cultures of murine bone marrow. Their appearance coincides with the growth of macrophages which become the predominant cells in culture after an initial phase favoring granulopoiesis. Host mice bearing diffusion chamber cultures were given regular injections of [3H]thymidine beginning prior to the development of MNGCs. The nuclei in MNGCs in these cultures were nonuniformly labeled. In any given MNGC all, none, or some of the nuclei might be labeled and the percentage of labeled nuclei was similar to the percentage labeling of the mononuclear macrophages in these cultures. These findings demonstrate that under these experimental conditions MNGCs arise primarily from cell fusion rather than nuclear division and that they are the random fusion products of both quiescent and actively dividing macrophages.","PeriodicalId":20675,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine","volume":" ","pages":"359-62"},"PeriodicalIF":0.0,"publicationDate":"1982-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3181/00379727-170-41442","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35262368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1982-07-01DOI: 10.3181/00379727-170-41437
W C Thomas
Abstract At high citrate:metal ratios the small polyvalent metals Fe3+, Be2+, Al3+, and Cr3+ interact with citrate to form potent inhibitors of both calcium uptake by a calcifiable matrix and crystal formation from a metastable solution of calcium phosphate. These unique metal-citrate complexes are effective inhibitors at 0.2-30 × 10−6 M, with iron (III) citrate being the most potent. The inhibitor effects of mixtures of the metal-citrate complexes are additive. These observations define a new role for citrate and indicate how certain trace elements may, by interaction with citrate, be important determinants in the control of calcium salt deposition in vivo. The possible pertinence of these observations to the deposition of calcium salts within the kidney and to the prevalence of idiopathic calculi in various geographic areas is now under investigation.
{"title":"Trace metal-citric acid complexes as inhibitors of calcification and crystal formation.","authors":"W C Thomas","doi":"10.3181/00379727-170-41437","DOIUrl":"https://doi.org/10.3181/00379727-170-41437","url":null,"abstract":"Abstract At high citrate:metal ratios the small polyvalent metals Fe3+, Be2+, Al3+, and Cr3+ interact with citrate to form potent inhibitors of both calcium uptake by a calcifiable matrix and crystal formation from a metastable solution of calcium phosphate. These unique metal-citrate complexes are effective inhibitors at 0.2-30 × 10−6 M, with iron (III) citrate being the most potent. The inhibitor effects of mixtures of the metal-citrate complexes are additive. These observations define a new role for citrate and indicate how certain trace elements may, by interaction with citrate, be important determinants in the control of calcium salt deposition in vivo. The possible pertinence of these observations to the deposition of calcium salts within the kidney and to the prevalence of idiopathic calculi in various geographic areas is now under investigation.","PeriodicalId":20675,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine","volume":" ","pages":"321-7"},"PeriodicalIF":0.0,"publicationDate":"1982-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3181/00379727-170-41437","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35262367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1982-06-01DOI: 10.3181/00379727-170-41412
J M Ploucha, S J Bursian, R K Ringer, J B Scott
Abstract We have recently reported that hemorrhage to a mean arterial blood pressure (MABP) of 50 mm Hg in the chicken has no effect on total peripheral resistance or skeletal muscle vascular resistance (judged from changes in limb perfusion pressure (Pp) during constant blood flow). In the present study we report the effect of a more severe hemorrhagic hypotension (MABP = 25 mm Hg) on skeletal muscle vascular resistance in the constantly perfused hindlimb of the chicken following severance of the sciatic nerve trunk, bilateral cervical vagotomy, α-adrenergic blockade, or during artificial perfusion of the head with arterial blood. Concentrations of serotonin (SER), dopamine (DA), and norepinephrine (NE) in plasma were determined at different levels of hypotension. While hemorrhage to MABP = 50 mm Hg had no effect on P p, a further hemorrhage to MABP = 25 mm Hg produced a sharp rise in P p which was unaffected by severance of the sciatic nerve truck or bilateral cervical vagotomy. This vasoconstriction could be completely climinated by intraarterial infusion of phentolamine or by pump perfusing the head during the hypotensive interval. Furthermore, concentrations of SER, DA, and NE were significantly elevated only when the rise in P p was evident. We conclude that the vasoconstrictor response to severe hemorrhagic hypotension in the chicken is primarily mediated by an increase in circulating catecholamines due to cerebral ischemia, rather than a baroreflex.
{"title":"Effects of severe hemorrhagic hypotension on the vasculature of the chicken.","authors":"J M Ploucha, S J Bursian, R K Ringer, J B Scott","doi":"10.3181/00379727-170-41412","DOIUrl":"https://doi.org/10.3181/00379727-170-41412","url":null,"abstract":"Abstract We have recently reported that hemorrhage to a mean arterial blood pressure (MABP) of 50 mm Hg in the chicken has no effect on total peripheral resistance or skeletal muscle vascular resistance (judged from changes in limb perfusion pressure (Pp) during constant blood flow). In the present study we report the effect of a more severe hemorrhagic hypotension (MABP = 25 mm Hg) on skeletal muscle vascular resistance in the constantly perfused hindlimb of the chicken following severance of the sciatic nerve trunk, bilateral cervical vagotomy, α-adrenergic blockade, or during artificial perfusion of the head with arterial blood. Concentrations of serotonin (SER), dopamine (DA), and norepinephrine (NE) in plasma were determined at different levels of hypotension. While hemorrhage to MABP = 50 mm Hg had no effect on P p, a further hemorrhage to MABP = 25 mm Hg produced a sharp rise in P p which was unaffected by severance of the sciatic nerve truck or bilateral cervical vagotomy. This vasoconstriction could be completely climinated by intraarterial infusion of phentolamine or by pump perfusing the head during the hypotensive interval. Furthermore, concentrations of SER, DA, and NE were significantly elevated only when the rise in P p was evident. We conclude that the vasoconstrictor response to severe hemorrhagic hypotension in the chicken is primarily mediated by an increase in circulating catecholamines due to cerebral ischemia, rather than a baroreflex.","PeriodicalId":20675,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine","volume":" ","pages":"160-4"},"PeriodicalIF":0.0,"publicationDate":"1982-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3181/00379727-170-41412","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35262357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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