Acta physiologica, pharmacologica et therapeutica latinoamericana : organo de la Asociacion Latinoamericana de Ciencias Fisiologicas y [de] la Asociacion Latinoamericana de Farmacologia最新文献

Lp(a) and LDL2 were used for detailed fatty acid analyses and tested in an in vitro model for promotion of fibroblast-mediated collagen lattice contraction to determine possible compositional and functional differences between these two apoB-containing lipoprotein species. Autologous Lp(a) was more saturated with respect to fatty acid composition than LDL2 in triglyceride and cholesterol ester lipid classes and had differences in the fatty acid content of phospholipids. Functionally, LDL2 promoted rapid fibroblast-mediated contraction while Lp(a) was significantly less active in promoting rapid contraction on a protein per weight basis. These studies suggest a synthetic route for Lp(a) diverging from the majority of other apoB-containing lipoproteins and significant activity of LDL2 in a collagen lattice contraction system.

Diabetic nephropathy is associated with increased urinary albumin and reduce kallikrein excretion. Increased activity of the renal kallikrein-kinin system has been suggested as one of the possible mechanisms underlying diabetic hyperfiltration. The present study shown that the Kallikrein-kinin system is progressively increased in the diabetic-pregnant rats at 7, 14, 21 days; 48 and 7 days after pregnancy (P < 0.05 vs Control). However, this increase during diabetic pregnancy did not reached the levels of control pregnancy. On the other hand albumin excretion shown a significant and progressive renal damage in the diabetic state. These findings suggest that the diabetic pregnancy could impair the renal hemodynamic, but, on the other side could modulate the vasodilator system at pregnancy in the attempt to protect the fetus.

The hyperlipidemia posttransplant has been largely attributed to immunosuppressant agents. In the present work we evaluated the effect of oral administration of cyclosporine (5 mg/kg/day) and/or methyl-prednisone (1 mg/kg/day) on lipid composition and polyunsaturated fatty acid biosynthesis in normal adult male rats. The results obtained showed that both agents produced a delay on the growth together with a significant loss of body weight. In liver microsomal fraction from rats treated with methyl-prednisone, a depression in delta 6 and delta 5 desaturation activities, was observed. This effect was corroborated in the fatty acid pattern through the enhancement of linoleic and dihomo-gamma-linolenic acids, and a depression of arachidonic acid. Similar results were noticed in those rats treated with both drugs when compared to the controls. No changes were observed either in the amount of liver microsomal total lipids or in the fatty acid composition of kidney and testis microsomes, as well as in erythrocyte membranes, among the different groups studied. Cyclosporine alone produced a significant depression in plasma triglycerides and showed no modifications in the other lipid parameters studied compared to the controls. Fluorescence anisotropy measured in the different membranes was not modified by the several treatments used. In view of the aforementioned data, it can be stated that methyl-prednisone would be the responsible for many of the lipid disorders that can be observed in posttransplant patients when they are subjected to the combined immunotherapy with cyclosporine.

The mechanisms underlying the muscle relaxant activity of 1-bebeerine (BB), a tertiary alkaloid isolated from the roots of Chondrodendron platyphyllum, were examined in mammalian and amphibian skeletal muscles. Injections of BB (0.05-1 g/kg, i.p.) in rats caused a dose-related flaccid paralysis and respiratory arrest at high doses. In isolated rat diaphragm and toad sartorius muscles, BB depressed the indirectly elicited muscle twitches (IC50: 228 microM and 5.4 microM, respectively, at 22 degrees C) and blocked the nerve-elicited muscle action potential. The neuromuscular blockade was not reversed by neostigmine (10 microM). High concentrations of BB (170 and 340 microM) caused muscle contracture unrelated to the junctional blockade, and intensified by increasing the bath temperature. Analysis of the contraction properties showed that BB (40 and 80 microM) increased the twitch/tetanus ratio (46% and 125%) and prolonged the relaxation time; the falling phase of the directly elicited action potential in toad sartorius muscle fibers was slower probably by a decreased potassium conductance. BB (0.1-340 microM) reduced the binding of [125l]alpha--bungarotoxin to the junctional ACh receptor of the rat diaphragm (IC50: 47.7 microM, at 37 degrees C. At low concentrations BB (1.5-15 microM) induced either opening or blockade of the ACh receptor-ionic channel. The results showed that BB blocked noncompetitively the neuromuscular transmission through a mechanism that affects the ACh recognition site and the ionic channel properties. The alkaloid also produced muscle contracture and changed the contractile properties through its extra-junctional action at the calcium handling by the sarcoplasmic reticulum or the contractile machinery.

It is now well known that zinc is an essential micronutrient. Even though much information is available, there are many points that remain to be studied. zinc is absorbed by the intestine and transported in the plasma by albumin, forming a small exchangeable pool, which is rapidly exhausted even in cases of mild deficiency. zinc is essential for the activity of about 70 enzymes among other functions. Therefore, zinc deficiency produces a great number of clinical disorders, the symptoms of which may range between mild up to serious dysfunctions. These problems are corrected by a dietary supplementation with zinc. The lack of a reliable method to determine the zinc nutritional status reflects the problem to estimate the metal recommended dietary allowances, which are difficulty met specially by children, old persons and pregnant women which constitute the main risk groups. Although our knowledge concerning zinc toxicity is scarce, it is well known that the amounts of zinc that produces toxic effects are much higher than those that are contained in regular diets as well as in diets supplemented with this metal. Therefore, the need of the development of effective strategies, like food fortification with proper zinc compounds, appears as an attractive alternative in order to prevent and/or correct the deficiency of this vital element and to improve the health and the life quality of the whole population.

Actions and interactions of spontaneous diabetes mellitus (DM) and natural estrous cycles (sex seasons) on the regulation of serum nonesterified fatty acids (NEFAs) and free glycerol (FG) levels in bitches in the fasting condition and during i.v. glucose (IVGTT) and insulin (ITT) tolerance tests, were studied. DM increased serum NEFAs concentration both in the basal condition and during IVGTT; it provoked a fall response to glucose load which is absent in normal controls. Estrous cycles did not modify these observations. Serum NEFAs levels during ITT were unresponsive in normal and diabetic bitches at every sex stage; flat, overlapped serum NEFAs profiles were then observed except for the diabetic group at A, which showed an early abrupt fall response of this variable from its high base line. DM increased also serum FG concentration in the fasting condition and during IVGTT. In the normal controls, serum FG base line was not affected by sex status; similarly shaped, increasing, overlapped curves during the test were observed. In the diabetic bitches "in season" (either phase), serum FG basal value was hardly above in respect to anestrous, but during IVGTT their flat profiles coincided. DM increased serum FG concentration in the basal condition and during ITT, and modified the profiles of this variable. In normal dogs in the basal condition, serum FG concentration remained unaffected by sex status; this variable hard, transiently increased during ITT, which was not influenced by "sex seasons"; therefore, similarly shaped, overlapped serum FG profiles were then observed. In the normal and diabetic bitches, serum-FG base line was not changed by "sex seasons". During ITT, serum FG mean profile in the diabetic bitches at EP was modestly above that observed in those at LP; differences for any other comparisons in normals or diabetic bitches were nonsignificant. As reported by us elsewhere, impaired glucose metabolism and absolute insulin deficiency induced ketose-prone, acidotic, insulin-dependent diabetic chryses in certain normal and diabetic beaches "in season" studied here. The unability of these animals for hydrolizing glyceride-glycerol via lipoproteinlipase (IVGTT) or via hormone sensitive fractions of lipase (ITT) and the abolished serum NEFAs suppressibility during modest hiperinsulinemia (ITT) appear to contribute to the production of such chryses. Results are discussed on the basis of interactions of serum NEFAs and FG with respective blood sugar and serum immunoreactive insulin levels as influenced by DM and estrous cycle.

Hair cells can be damaged by countless agents, among them aminoglycoside antibiotics. In the chick cochlea, the hair cell loss can be recovered by regeneration. The objectives of the present investigation were to study the time progression of injury caused by gentamicin and the regeneration process in chick hair cells. Gentamicin was administered in a single subcutaneous dose of 125 or 250 mg/kg to two groups of 3-day old chicks. The cochleae were processed for analysis by scanning electron microscopy on the 1st, 3rd, 5th and 20th day after injection. The cellular sequence of degeneration and regeneration was studied. On the 20th day, most it he damaged cochlear area showed regenerated hair and support cells. Stereocilia and microvilli were observed on the apical surface of the regenerated hair cells.

This study was conducted to compare the analgesic action of Lysine Clonixinate (LC) vs Paracetamol/Codeine association (PC) in the treatment of postepisiotomy pain in primiparae women: 131 primiparous patients with moderate-to-severe postepisiotomy pain were enrolled in a double blind dummy design study and randomly allocated to either treatment with fixed doses of LC 125 mg or Paracetamol 500 mg+Codeine 30 mg 6 qh during 24 hours. Intensity of spontaneous pain and pain on walking was assessed according to a visual analog scale (VAS) and patient's assessment before receiving treatment and after 1, 2, 6 and 24 hours. Intensity of spontaneous pain was reduced in 24 hours from 4.28 +/- 2.11 to 1.73 +/- 1.46 (P < 0.0001) in the LC group and from 4.78 +/- 2.08 to 1.90 +/- 1.72 in the PC-treated group (p < 0.0001); with no significant differences between treatments. 54% of the patients treated with LC and 55% of those receiving PC showed onset of analgesic action 30 minutes following dose administration. Patient's final global assessment revealed that 95% of LC-treated patients and 96% of the PC group showed total or partial pain relief during the first treatment day. No sleep disturbances were seen during the night in 75% of patients. Only one patient receiving LC showed nausea not requiring treatment discontinuation. It is concluded that both treatments are equally effective to relieve moderate-to-severe postepisiotomy pain.

The aim of the present investigation was to evaluate the potential modulatory effect of the guinea pig tracheal smooth muscle intrinsic tone on the relaxant responses to sodium nitroprusside and the effects of methylene blue on this response. Paired tracheal chains were mounted for isotonic contractions under 500 mg of tension in Krebs-Henseleit solution. The intrinsic modulatory tone was inhibited by indomethacin, in a concentration that did not have any effect over carbachol induced contractions. Sodium nitroprusside-induced relaxations were the same in the absence or presence of the modulatory tone. Methylene blue inhibited 50% sodium nitroprusside-induced relaxations, in the presence or absence of the intrinsic system. This suggests that sodium nitroprusside-induced relaxations are mediated through guanylyl-cyclase activation and that these are not under the modulation of the intrinsic prostaglandinergic tone.