The littoral alga Chaetomorpha linum is especially able to maintain a constant turgor pressure in the cell by regulating the internal osmotic pressure, if the salt content of the sea water changes. Experiments in artificial isotonic sea water with a constant sodium concentration, but variable potassium concentrations (from 1 to 50 mMol/1) prove, that the decrease or increase of the potassium concentration in the medium (CKa) is an essential cause for this regulation of the turgor pressure besides the change of the osmotic pressure of the medium, which was thought to be the predominant cause till now. In the examined concentration range the ratio CKa to CK1 (potassium concentration in the cell) depends linear on CKa in the steady state. At low values of CKa (< 10 mMol/1) the decrease in CK1 is compensated by a reversible sodium uptake only in part, and this leads to partly high changes in the cell turgor pressure, although the osmotic pressure of the medium remains constant. The results are discussed on the basis of carrier models.
{"title":"[Cell turgor and selective ion transport of Chaetomorpha linum].","authors":"E Steudle, U Zimmermann","doi":"10.1515/znb-1971-1216","DOIUrl":"https://doi.org/10.1515/znb-1971-1216","url":null,"abstract":"The littoral alga Chaetomorpha linum is especially able to maintain a constant turgor pressure in the cell by regulating the internal osmotic pressure, if the salt content of the sea water changes. Experiments in artificial isotonic sea water with a constant sodium concentration, but variable potassium concentrations (from 1 to 50 mMol/1) prove, that the decrease or increase of the potassium concentration in the medium (CKa) is an essential cause for this regulation of the turgor pressure besides the change of the osmotic pressure of the medium, which was thought to be the predominant cause till now. In the examined concentration range the ratio CKa to CK1 (potassium concentration in the cell) depends linear on CKa in the steady state. At low values of CKa (< 10 mMol/1) the decrease in CK1 is compensated by a reversible sodium uptake only in part, and this leads to partly high changes in the cell turgor pressure, although the osmotic pressure of the medium remains constant. The results are discussed on the basis of carrier models.","PeriodicalId":23706,"journal":{"name":"Zeitschrift fur Naturforschung. Teil B, Chemie, Biochemie, Biophysik, Biologie und verwandte Gebiete","volume":"26 12","pages":"1276-82"},"PeriodicalIF":0.0,"publicationDate":"1971-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/znb-1971-1216","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15503180","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}
Intact and adrenalectomized rats were irradiated with 900 R or treated with 10 mg per 100 g body weight of hydrocortisone. The incorporation of orotic acid-6-14C for 2 hours into liver free uridine nucleotides, nuclear and cytoplasmic RNA and RNA fractions obtained by agar gel electrophoresis, were studied. The obtained results show that in intact animals both irradiation and hydrocortisone induce a higher labelling of cytoplasmic and nuclear liver RNA. The higher labelling of RNA is not correlated with a higher labelling of the free uridine nucleotides. The labelling of all electrophoretic RNA fractions is increased to approximately the same extent under the action of either hydrocortisone or irradiation. Irradiation or hydrocortisone treatment of adrenalectomized rats causes also a higher labelling of liver nuclear and cytoplasmic RNA. The higher labelling of RNA is not correlated with that of free uridine nucleotides and affects all electrophoretic RNA fractions.. The combined action of irradiation and hydrocortisone shows an additive effect on the labelling of nuclear and cytoplasmic liver RNA. The obtained results indicate that whole body irradiation causes an increased synthesis of both ribosomal and non-ribosomal RNA’s of rat liver. Since the same effect is observed in intact and adrenalectomized animals it may be concluded that the stimulation of liver RNA synthesis by irradiation is not mediated by the adrenals.
{"title":"Effect of irradiation on the biosynthesis of liver ribonucleic acids in intact and adrenalectomized rats.","authors":"P G Popov, L I Valeva-Dimitrova, A A Hadjiolov","doi":"10.1515/znb-1971-1217","DOIUrl":"https://doi.org/10.1515/znb-1971-1217","url":null,"abstract":"Intact and adrenalectomized rats were irradiated with 900 R or treated with 10 mg per 100 g body weight of hydrocortisone. The incorporation of orotic acid-6-14C for 2 hours into liver free uridine nucleotides, nuclear and cytoplasmic RNA and RNA fractions obtained by agar gel electrophoresis, were studied. The obtained results show that in intact animals both irradiation and hydrocortisone induce a higher labelling of cytoplasmic and nuclear liver RNA. The higher labelling of RNA is not correlated with a higher labelling of the free uridine nucleotides. The labelling of all electrophoretic RNA fractions is increased to approximately the same extent under the action of either hydrocortisone or irradiation. Irradiation or hydrocortisone treatment of adrenalectomized rats causes also a higher labelling of liver nuclear and cytoplasmic RNA. The higher labelling of RNA is not correlated with that of free uridine nucleotides and affects all electrophoretic RNA fractions.. The combined action of irradiation and hydrocortisone shows an additive effect on the labelling of nuclear and cytoplasmic liver RNA. The obtained results indicate that whole body irradiation causes an increased synthesis of both ribosomal and non-ribosomal RNA’s of rat liver. Since the same effect is observed in intact and adrenalectomized animals it may be concluded that the stimulation of liver RNA synthesis by irradiation is not mediated by the adrenals.","PeriodicalId":23706,"journal":{"name":"Zeitschrift fur Naturforschung. Teil B, Chemie, Biochemie, Biophysik, Biologie und verwandte Gebiete","volume":"26 12","pages":"1282-7"},"PeriodicalIF":0.0,"publicationDate":"1971-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/znb-1971-1217","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15503181","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}
In part 1 a method is described how the nerve current iax of passively conducting nerves can be measured. iax is shown to be a quantitative measure of the receptor potential. For a known state of function of the photoreceptor iax can be used to calculate the resistance of the nerve. Part 2 is concerned with the primary electrical reaction (receptor potential) of vision. Formulae are derived which allow to calculate 1. the quantity of absorbed light (input); 2. the charge flux (output). The ratio of output to input is the photo-electric efficiency ηq. With ηq it is possible to estimate the turnover of ions and energy of the transduction reaction.
{"title":"Derivation of the photo-electric efficiency of photoreceptors and a method of extracellular measurement of nerve current. I.","authors":"C C Krischer","doi":"10.1515/znb-1971-1222","DOIUrl":"https://doi.org/10.1515/znb-1971-1222","url":null,"abstract":"In part 1 a method is described how the nerve current iax of passively conducting nerves can be measured. iax is shown to be a quantitative measure of the receptor potential. For a known state of function of the photoreceptor iax can be used to calculate the resistance of the nerve. Part 2 is concerned with the primary electrical reaction (receptor potential) of vision. Formulae are derived which allow to calculate 1. the quantity of absorbed light (input); 2. the charge flux (output). The ratio of output to input is the photo-electric efficiency ηq. With ηq it is possible to estimate the turnover of ions and energy of the transduction reaction.","PeriodicalId":23706,"journal":{"name":"Zeitschrift fur Naturforschung. Teil B, Chemie, Biochemie, Biophysik, Biologie und verwandte Gebiete","volume":"26 12","pages":"1322-5"},"PeriodicalIF":0.0,"publicationDate":"1971-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/znb-1971-1222","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15503185","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}
{"title":"On the nature of achromatic lesions (\"gaps\") induced by X-rays in chromosomes of Vicia faba.","authors":"W Scheid, H Traut","doi":"10.1515/znb-1971-1245","DOIUrl":"https://doi.org/10.1515/znb-1971-1245","url":null,"abstract":"","PeriodicalId":23706,"journal":{"name":"Zeitschrift fur Naturforschung. Teil B, Chemie, Biochemie, Biophysik, Biologie und verwandte Gebiete","volume":"26 12","pages":"1384-5"},"PeriodicalIF":0.0,"publicationDate":"1971-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/znb-1971-1245","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15506935","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}
In synchronized growing yeast, the level of acid-soluble purine deoxynucleotides, as determined by the diphenylamine reaction, fluctuates rhythmically: A rapid increase each time before DNA starts to replicate is followed by a considerable decrease during DNA augmentation. Delay of DNA replication by irradiation of synchronized yeast with 50 kr of X-rays results in a stepwise augmentation of deoxyribose derivatives. The fluctuating behaviour is restored, when DNA starts to increase, again. During asynchronous growth acid-soluble deoxyribosidic compounds are augmented with a considerably increased rate, when DNA replication is delayed by X-rays. The resulting unusual pool seize is maintained, even if DNA replication is resumed to a normal degree, but the rate of further increase is reduced to normal values. Parts of the rapidly accumulated deoxyribosidic material differ with some properties from purine deoxynucleotides.
{"title":"Acid-soluble deoxynucleotides and DNA synthesis in growing yeast after x-irradiation. I. Diphenylamine positive material in synchronized and asynchronously growing cells.","authors":"H Eckstein","doi":"10.1515/znb-1971-1214","DOIUrl":"https://doi.org/10.1515/znb-1971-1214","url":null,"abstract":"In synchronized growing yeast, the level of acid-soluble purine deoxynucleotides, as determined by the diphenylamine reaction, fluctuates rhythmically: A rapid increase each time before DNA starts to replicate is followed by a considerable decrease during DNA augmentation. Delay of DNA replication by irradiation of synchronized yeast with 50 kr of X-rays results in a stepwise augmentation of deoxyribose derivatives. The fluctuating behaviour is restored, when DNA starts to increase, again. During asynchronous growth acid-soluble deoxyribosidic compounds are augmented with a considerably increased rate, when DNA replication is delayed by X-rays. The resulting unusual pool seize is maintained, even if DNA replication is resumed to a normal degree, but the rate of further increase is reduced to normal values. Parts of the rapidly accumulated deoxyribosidic material differ with some properties from purine deoxynucleotides.","PeriodicalId":23706,"journal":{"name":"Zeitschrift fur Naturforschung. Teil B, Chemie, Biochemie, Biophysik, Biologie und verwandte Gebiete","volume":"26 12","pages":"1266-70"},"PeriodicalIF":0.0,"publicationDate":"1971-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/znb-1971-1214","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15503178","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}
In adult males of the giant silk moth Hyalophora cecropia (L.) the amount of juvenile hormone (JH) extractable from the abdomens increases sharply between the first and fourth day of adult life; 4-8 day-old moths contain up to 6 μg. During the biosynthesis, L-methionine provides the ester methyl group of both JH and its lower homologue JH-II. It does not contribute to the formation of the carbon skeleton. Farnesol, farnesyl pyrophosphate, and propionate are not utilized. Mevalonate is extensively incorporated into trans,trans-farnesol, but not into the sesquiterpene-like hormone. This result indicates that JH is not synthesized via mevalonate in the adult moths. Label of 2-14C-acetate was recovered in both JH and farnesol; the incorporation rate, however, was very small. The label of JH was located in the carbon skeleton.
{"title":"On the biosynthesis of juvenile hormone in the adult Cecropia moth.","authors":"M Metzler, K H Dahm, H Meyer D Röller","doi":"10.1515/znb-1971-1215","DOIUrl":"https://doi.org/10.1515/znb-1971-1215","url":null,"abstract":"In adult males of the giant silk moth Hyalophora cecropia (L.) the amount of juvenile hormone (JH) extractable from the abdomens increases sharply between the first and fourth day of adult life; 4-8 day-old moths contain up to 6 μg. During the biosynthesis, L-methionine provides the ester methyl group of both JH and its lower homologue JH-II. It does not contribute to the formation of the carbon skeleton. Farnesol, farnesyl pyrophosphate, and propionate are not utilized. Mevalonate is extensively incorporated into trans,trans-farnesol, but not into the sesquiterpene-like hormone. This result indicates that JH is not synthesized via mevalonate in the adult moths. Label of 2-14C-acetate was recovered in both JH and farnesol; the incorporation rate, however, was very small. The label of JH was located in the carbon skeleton.","PeriodicalId":23706,"journal":{"name":"Zeitschrift fur Naturforschung. Teil B, Chemie, Biochemie, Biophysik, Biologie und verwandte Gebiete","volume":"26 12","pages":"1270-6"},"PeriodicalIF":0.0,"publicationDate":"1971-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/znb-1971-1215","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15503179","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}
{"title":"Studies on the recovery of X-irradiated bacteria.","authors":"P Mukherjee","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":23706,"journal":{"name":"Zeitschrift fur Naturforschung. Teil B, Chemie, Biochemie, Biophysik, Biologie und verwandte Gebiete","volume":"26 12","pages":"1383-4"},"PeriodicalIF":0.0,"publicationDate":"1971-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15506934","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}
A microbioautographic method for the identification of pteroylglutamic acid derivatives and their glutamyl conjugates is described. Chromatograms or pherograms of mixtures of the compounds are treated with chicken pancreas conjugase, followed by tetrazolium bioautography. This combined procedure allows qualitative and semi-quantitative analyses of folate compounds in biological material in the nano- and picomole range. Application of this method to extracts of different sources proved the following: (1) the presence of 10-formyl pteroyl-γ-heptaglutamate as the only folate derivative in yeast boiled juice; (2) Clostridium kluyverii and pastorianum contain almost exclulively pteroyl-γ-triglutamic acid; (3) the main folate activity in human leucocytes is 5-methyltetrahydropteroyl monoglutamate.
{"title":"[Tetrazolium bioautography of pteroylglutamic acid conjugates].","authors":"I Schlie, L Jaenicke","doi":"10.1515/znb-1971-1213","DOIUrl":"https://doi.org/10.1515/znb-1971-1213","url":null,"abstract":"A microbioautographic method for the identification of pteroylglutamic acid derivatives and their glutamyl conjugates is described. Chromatograms or pherograms of mixtures of the compounds are treated with chicken pancreas conjugase, followed by tetrazolium bioautography. This combined procedure allows qualitative and semi-quantitative analyses of folate compounds in biological material in the nano- and picomole range. Application of this method to extracts of different sources proved the following: (1) the presence of 10-formyl pteroyl-γ-heptaglutamate as the only folate derivative in yeast boiled juice; (2) Clostridium kluyverii and pastorianum contain almost exclulively pteroyl-γ-triglutamic acid; (3) the main folate activity in human leucocytes is 5-methyltetrahydropteroyl monoglutamate.","PeriodicalId":23706,"journal":{"name":"Zeitschrift fur Naturforschung. Teil B, Chemie, Biochemie, Biophysik, Biologie und verwandte Gebiete","volume":"26 12","pages":"1260-5"},"PeriodicalIF":0.0,"publicationDate":"1971-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/znb-1971-1213","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15503177","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}
{"title":"The photo-electric efficiency of the median and the lateral photoreceptor of the barnacle Balanus eburneus. II.","authors":"C C Krischer","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":23706,"journal":{"name":"Zeitschrift fur Naturforschung. Teil B, Chemie, Biochemie, Biophysik, Biologie und verwandte Gebiete","volume":"26 12","pages":"1326-35"},"PeriodicalIF":0.0,"publicationDate":"1971-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15503186","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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