Adição de óleo de palma na dieta sobre a lipidemia e a qualidade do sêmen de bubalinos (Bubalus bubalis) / Addition of palm oil to diet on serum lipid profile and seminal quality of buffaloes (Bubalus bubalis)

O estudo visou investigar o efeito da suplementação dietética com óleo de palma sobre o perfil sérico lipídico e as características seminais de touros bubalinos (Bubalus bubalis), bem como suas correlações. Doze touros foram alocados no Grupo CONT (n=5) ou Grupo ÓLEO (n=7) e receberam alimentação isoproteica composta por silagem de milho e concentrado (milho triturado, farelo de trigo e ureia), com proporção volumoso/concentrado de 50%, durante 130 dias (Períodos 1 e 2). Diferencialmente, óleo de palma foi adicionado ao concentrado (2% MS) do Grupo ÓLEO. Sêmen e sangue foram colhidos quinzenalmente. Houve aumento nas concentrações séricas de colesterol, HDL e lipídios totais nos animais do Grupo ÓLEO, enquanto o período influenciou nas taxas de colesterol, LDL, lipídios totais e VLDL (P<0,05). Houve decréscimo no turbilhonamento e discreta redução na integridade de membranas nos animais do Grupo ÓLEO (P<0,05). Correlações significativas foram encontradas entre triglicerídeos e defeitos menores (r=-0,412; P=0,006), LDL e defeitos totais (r=-0,333; P=0,030), lipídios totais e defeitos menores (r=-0.366; P= 0,017), lipídios totais e defeitos totais (r=-0.309; P= 0,046), e VLDL e viabilidade espermática (r=0,381; P=0,012), apontando efeitos positivos da maior lipidemia na morfologia e na viabilidade espermática. O uso de óleo de palma alterou o perfil lipídico sérico, mas não favoreceu per se os parâmetros seminais relacionados com o potencial de fertilidade dos touros.

The study aimed to investigate the effect of dietary supplementation with palm oil on serum lipid profile, the seminal characteristics of buffaloes (Bubalus bubalis) and the correlations between them. Twelve bulls were divided into Group CONT (n = 5) or Group OIL (n = 7). Animals in both groups were fed with isoproteic diets composed of corn silage and concentrated (ground corn, wheat bran and urea), with 50% forage/concentrate ratio, during 130 days (Periods 1 and 2). Palm oil (2%DM) was added to diet offered to Group OIL. Semen and blood samples were collected every two weeks. Increased serum levels of cholesterol, HDL and total lipids were observed for Group OIL, while the period influenced on cholesterol, LDL, total lipids and VLDL (P<0,05). Treatment decreased gross motility (P<0.05) and slightly reduced sperm membrane integrity (P<0.05) in animals of Group OIL. There were significant correlations between triglycerides and minor defects (r=-0.412, P=0.006), LDL and total defects (r=-0.333, P=0.030), total lipids and minor defects (r=-0.366, P=0.017), VLDL and spermatic viability (r=0.381, P=0.012), and total lipids and totals defects (r=-0.309, P=0.046), highlighting positive effects of higher lipid serum levels on sperm morphology and viability. The incorporation of palm oil in the diet altered the serum lipid profile, but it showed no positive effect on seminal parameters related to the potential of bull fertility.

Soybean meal induces intestinal inflammation in common carp (Cyprinus carpio L.).

The development of soybean meal (SBM) induced enteritis in the hindgut of the omnivorous common carp (Cyprinus carpio L.). The developed condition was assessed when carp, continuously fed on animal protein, were transferred to a diet in which 20% of the protein was replaced by SBM. After week 1, most of the inflammation parameters were already present, but at week 3, a strong aggravation of the condition was observed which included a shortening of the mucosal folds, the disappearance of the supranuclear vacuoles, an increased number of goblet cells, a thickened lamina propria and sub-epithelial mucosa with increased numbers of basophilic granulocytes as well as a decreased uptake capacity of enterocytes (impaired endocytosis and microvilli). Contrary to previous observations made with respect to Atlantic salmon, common carp start to recover from the fourth to the fifth week after switching to SBM feeding. At this stage, the supranuclear vacuoles refill and most of the parameters revert to basal levels. During the enteritis process, a real-time quantitative PCR analysis was conducted to measure the expression of inflammatory and anti-inflammatory cytokine genes in the isolated intraepithelial lymphocytes (IEL). The pro-inflammatory interleukin 1 beta (IL-1 beta) and tumour necrosis factor alpha1 (TNF-alpha1) genes were up-regulated during the inflammation process while the anti-inflammatory interleukin 10 (IL-10) was down-regulated after an initial up-regulation at week 1. Transforming growth factor beta (TGF-beta) expression showed an up-regulation from week 3 onwards despite the high Ct value and the low primer efficiency shown. This study confirms the contribution of IEL (mainly T-like cells) and basophils in the enteritis process. In addition, the results show a clear involvement of up- and down-regulated cytokine genes in both the onset and recovery of the SBM-induced enteritis in the hindgut of carp.

Involuçäo uterina em um rebanho Gir leiteiro segundo o período pós-parto e o número de pariçöes / Uterine involution in dairy Gir cows, according to postpartum period and parity

Durante três anos, vacas Gir leiteiro da Fazenda Experimental da EPAMIG, em Uberaba-MG, foram examinadas, pela palpaçäo retal, para verificaçäo da involuçäo uterina. Em 111 pariçöes de 104 vacas, a involuçäo dos cornos uterinos teve duraçäo média de 29,7ñ9,6 dias e, na maioria das vezes, a involuçäo da porçäo cervical demorou mais do que 43 dias. O tempo de involuçäo foi mais longo em vacas com maior número de partos. Na primeira semana, o útero permaneceu na cavidade abdominal (95,0 por cento), na segunda teve início o retorno do órgäo à pelve (8,2 por cento), na terceira aconteceram os primeiros casos de involuçäo completa dos cornos uterinos (20,6 por cento) e na sexta semana, a maior parte das vacas apresentavam involuçäo completa (82,9 por cento). Foram constatados seis casos de permanência do útero em involuçäo na cavidade abdominal e oito casos de localizaçäo pélvico/abdominal na quinta semana após o parto, detectados somente em vacas pluríparas. Observaram-se 19 casos de retrocesso na seqüência natural das fases da involuçäo. O retrocesso do útero para a cavidade abdominal só ocorreu em vacas com problemas sanitários. Em sete vacas com metrite, verificou-se prolongamento do tempo médio de involuçäo dos cornos uterinos e aumento do diâmetro cervical em relaçäo às demais vacas do rebanho

Evidence for the involvement of the crustacean hyperglycemic hormone in the regulation of lipid metabolism.

Effects of the crustacean hyperglycemic hormone on total lipids in the hemolymph of Chasmagnathus granulata and on free fatty acids, phospholipids, and triglycerides in the hemolymph of Carcinus maenas, as well as on their release by Orconectes limosus hepatopancreas in vitro, were investigated. Eyestalk ablation led to a significant decrease of total lipids in the hemolymph of C. granulata and of free fatty acid levels in C. maenas. Crustacean hyperglycemic hormone injections completely reversed the effects of eyestalk extirpation in short-term experiments. Crustacean hyperglycemic hormone also caused significant elevations of hemolymph phospholipids and triglycerides in eyestalkless C. maenas. The release of free fatty acids and phospholipids from O. limosus hepatopancreas in vitro was significantly increased in the presence of crustacean hyperglycemic hormone. These results suggest a physiological role for crustacean hyperglycemic hormone in the control of lipid metabolism in crustaceans. This role may be similar to that of the adipokinetic hormone of insects.

Partial recovery of erythrocyte glycogen in diabetic rats treated with phenobarbital.

Erythrocytes may play a role in glucose homeostasis during the postprandial period. Erythrocytes from diabetic patients are defective in glucose transport and metabolism, functions that may affect glycogen storage. Phenobarbital, a hepatic enzyme inducer, has been used in the treatment of patients with non-insulin-dependent diabetes mellitus (NIDDM), increasing the insulin-mediated glucose disposal. We studied the effects of phenobarbital treatment in vivo on glycemia and erythrocyte glycogen content in control and alloxan-diabetic rats during the postprandial period. In control rats (blood glucose, 73 to 111 mg/dl in femoral and suprahepatic veins) the erythrocyte glycogen content was 45.4 +/- 1.1 and 39.1 +/- 0.8 micrograms/g Hb (mean +/- SEM, N = 4-6) in the femoral artery and vein, respectively, and 37.9 +/- 1.1 in the portal vein and 47.5 +/- 0.9 in the suprahepatic vein. Diabetic rats (blood glucose, 300-350 mg/dl) presented low (P < 0.05) erythrocyte glycogen content, i.e., 9.6 +/- 0.1 and 7.1 +/- 0.7 micrograms/g Hb in the femoral artery and vein, respectively, and 10.0 +/- 0.7 and 10.7 +/- 0.5 in the portal and suprahepatic veins, respectively. After 10 days of treatment, phenobarbital (0.5 mg/ml in the drinking water) did not change blood glucose or erythrocyte glycogen content in control rats. In diabetic rats, however, it lowered (P < 0.05) blood glucose in the femoral artery (from 305 +/- 18 to 204 +/- 45 mg/dl) and femoral vein (from 300 +/- 11 to 174 +/- 48 mg/dl) and suprahepatic vein (from 350 +/- 10 to 174 +/- 42 mg/ dl), but the reduction was not sufficient for complete recovery. Phenobarbital also stimulated the glycogen synthesis, leading to a partial recovery of glycogen stores in erythrocytes. In treated rats, erythrocyte glycogen content increased to 20.7 +/- 3.8 micrograms/g Hb in the femoral artery and 30.9 +/- 0.9 micrograms/g Hb in the suprahepatic vein (P < 0.05). These data indicate that phenobarbital activated some of the insulin-stimulated glucose metabolism steps which were depressed in diabetic erythrocytes, supporting the view that erythrocytes participate in glucose homeostasis.

Partial recovery of erythrocyte glycogen in diabetic rats treated with phenobarbital

Erythorocytes may play a role in glucose homeostasis during the postprandial period. Erythrocytes from diabetic patients are defective in glucose transport and metabolism, functions that may affect glycogen storage. Phenobarbital, a hepatic enzyme inducer, has been used in the treatment of patients with non-insulin-dependent diabetes mellitus (NIDDM), increasing the insulin-mediated glucose disposal. We studied the effects of phenobarbital treatment in vivo on glycemia and erythrocyte glycogen content in control and alloxan-diabetic rats during the postprandial period. In control rats (blood glucose, 73 to 111 mg/dl in femoral and suprahepatic veins) the erythrocyte glycogens content was 45.4 + 1.1 and 39.1 + 0.8 mug/g Hb (mean + SEM, N = 4-6) in the femoral artery and vein, respectively, and 37.9 +1.1 in the portal vein and 47.5 + 0.9 in the suprahepatic vein. Diabetic rats (blood glucose 300-350 mg/dl) presented low (p<0.05) erythrocyte glycogen content, i.e., 9.6 + 0.1 and 7.1 + 0.7 mug/g Hb in the femoral artery and vein, respectively, and 10.0 + 0.7 and 10.7 + 0.5 in the portal and suprahepatic veins, respectively. After 10 days of tratment, phenobarbital (0.5 mg/ml in the drinking water) did not change blood glucose or erythrocyte glycogen content in control rats. In diabetic rats, however, it lowered (P<0.05) blood glucose in the femoral artery (from 305 + 18 to 204 + 45 mg/dl) and femoral vein (from 300 + 11 to 174 + 48 mg/dl) and suprahepatic vein (from 350 + 10 to 174 + 42 mg/dl), but the reduction was not sufficient for complete recovery. Phenobarbital also stimulated the glycogens synthesis, leading to a partial recovery of glycogen stores in erythrocytes. In treated rats, erythrocyte glycogen content increased to 20.7 + 3.8 mug/g Hb in the femoral artery and 30.9 + 0.9 mug/g Hb in the suprahepatic veins (p<0.05). These data indicate that phenobarbital activated some of the insulin-stimulated glucose matabolism steps which were depressed in diabetic srythrocytes, supporting the view that erythrocytes participate in glucose homeostasis.

Característica de produtos lácteos fermentados produzidos no Brasil: conteúdo de proteína e gordura, osmolaridade e valor calórico / characteristics of fermented dairy products in Brazil: protein and lipids content, osmolarity and caloric value

Foram estudadas algumas caracteristicas de produtos lócteos fermentados com vistas à sua utu/ilizaçäo em crianças com diarréia. Utilizaram-se amostras de iogurte de três marcas e tipos, coalhada industrializada e yakilt. Drtermonaram-se, nos mesmos, conteúdo de proteinas, , gorduras e osmolaridade e calculou-se o valor calórico destes produtos. A média dos niveis de proteina variou de 1,70 a 3,57, situando-se em torno de 3g por cento nos iogurtes e coalhadas. O conteúdo de gorduras variou de 0,07 a 3,56, sendo muito baixo nos iogurtes desnatados e no yakult (média de 0,58 e 0,07, respectivamente). A osmolaridade situou-se em torno de 490 nos iogurtes naturais, desnatados e nas coalhadas e foi bem mais alta nos produtos com acréscimo de açúcares (de 690 a 965)...

Amino acid sequence of TsTX-V, an alpha-toxin from Tityus serrulatus scorpion venom, and its effect on K+ permeability of beta-cells from isolated rat islets of Langerhans.

Highly purified Tityustoxin V (TsTX-V), an alpha-toxin isolated from the venom of the Brazilian scorpion Tityus serrulatus, was obtained by ion exchange chromatography on carboxymethylcellulose-52. It was shown to be homogeneous by reverse phase high performance liquid chromatography, N-terminal sequencing (first 39 residues) of the reduced and alkylated protein and by polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate and tricine. Following enzymatic digestion, the complete amino acid sequence (64 residues) was determined. The sequence showed higher homology with the toxins from the venoms of the North African than with those of the North and South American scorpions. Using the rate of 86Rb+ release from depolarized rat pancreatic beta-cells as a measure of K+ permeability changes, TsTX-V (5.6 micrograms/ml) was found to increase by 2.0-2.4-fold the rate of marker outflow in the presence of 8.3 mM glucose. This effect was persistent and slowly reversible, showing similarity to that induced by 100 microM veratridine, an agent that increases the open period of Na+ channels, delaying their inactivation. It is suggested that, by extending the depolarized period, TsTX-V indirectly affects beta-cell voltage-dependent K+ channels, thus increasing K+ permeability.

Effects of crustacean hyperglycemic hormones from Carcinus maenas and Orconectes limosus on blood and muscle glucose and glycogen concentration of Chasmagnathus granulata.

The effects of purified crustacean hyperglycemic hormones (CHH) from Carcinus maenas or Orconectes limosus, and of eyestalk extract of Chasmagnathus granulata on the blood and muscle glucose and glycogen concentration of Chasmagnathus granulata were investigated. Different groups of animals (at least 7 animals per group) were injected with CHH from either C. maenas or O. limosus CHH dissolved in saline (16 pmol/animal) or crude eyestalk extract of C. granulata (1 eyestalk equivalent/animal). All injections had a volume of 10 microliters. Blood and muscle glucose and glycogen concentrations were determined immediately before the injections and after 30, 60 and 120 min. CHH administration from both species, as well as eyestalk extract, resulted in marked hyperglycemia. However, their effects were different. CHH from C. maenas also caused a decrease in the glycogen concentration of blood (from 89.8 +/- 4.3 to 76.6 +/- 3.1 mg/100 ml) and muscle (from 7.9 +/- 0.8 to 4.0 +/- 0.7 mg/g) and glucose concentration of muscle (from 2.4 +/- 0.3 to 1.2 +/- 0.2 mg/g). CHH from O. limosus caused an increase of glycogen concentration of muscle (from 4.9 +/- 1.1 to 9.0 +/- 1.1 mg/g). The injection of eyestalk extract resulted also in a decrease of hemolymph glycogen (from 157.7 +/- 20.6 to 30.2 +/- 7.7 mg/100 ml). Therefore, C. granulata may have different receptors for CHH in its different tissues, and/or in the same tissue, which act through different metabolic pathways to achieve the same final result, i.e., hyperglycemia.

Effects of crustacean hyperglycemic hormones from Carcinus maenas and Orconectes limosus on blood and muscle glucose and glycogen concentration of Chasmagnathus granulata

The effects of purified crustacean hyperglycemic hormones (CHH) from Carcinus maenas or Orconectes limosus, and of eyestalk extract of Chasmagnathus granulata on the blood and muscle glucose and glycogen concentration of Chasmagnathus granulata were investigated. Different groups of animals (at least 7 animals per group) were injected with CHH from either C. maenas or O. limosus CHH dissolved in saline (16 pmol/animal) or crude eyestalk extract of C. granulata (1 eyestalk equivalent/animal). All injections had a volume of 10 microliters. Blood and muscle glucose and glycogen concentrations were determined immediately before the injections and after 30, 60 and 120 min. CHH administration from both species, as well as eyestalk extract, resulted in marked hyperglycemia. However, their effects were different. CHH from C. maenas also caused a decrease in the glycogen concentration of blood (from 89.8 +/- 4.3 to 76.6 +/- 3.1 mg/100 ml) and muscle (from 7.9 +/- 0.8 to 4.0 +/- 0.7 mg/g) and glucose concentration of muscle (from 2.4 +/- 0.3 to 1.2 +/- 0.2 mg/g). CHH from O. limosus caused an increase of glycogen concentration of muscle (from 4.9 +/- 1.1 to 9.0 +/- 1.1 mg/g). The injection of eyestalk extract resulted also in a decrease of hemolymph glycogen (from 157.7 +/- 20.6 to 30.2 +/- 7.7 mg/100 ml). Therefore, C. granulata may have different receptors for CHH in its different tissues, and/or in the same tissue, which act through different metabolic pathways to achieve the same final result, i.e., hyperglycemia

Charybdotoxin-sensitive K(Ca) channel is not involved in glucose-induced electrical activity in pancreatic beta-cells.

The effects of charybdotoxin (CTX) on single [Ca2+]-activated potassium channel (K(Ca)) activity and whole-cell K+ currents were examined in rat and mouse pancreatic beta-cells in culture using the patch-clamp method. The effects of CTX on glucose-induced electrical activity from both cultured beta-cells and beta-cells in intact islets were compared. K(Ca) activity was very infrequent at negative patch potentials (-70 less than Vm less than 0 mV), channel activity appearing at highly depolarized Vm. K(Ca) open probability at these depolarized Vm values was insensitive to glucose (10 and 20 mM) and the metabolic uncoupler 2,4 dinitrophenol (DNP). However, DNP blocked glucose-evoked action potential firing and reversed glucose-induced inhibition of the activity of K+ channels of smaller conductance. The venom from Leiurus quinquestriatus hebreus (LQV) and highly purified CTX inhibited K(Ca) channel activity when applied to the outer aspect of the excised membrane patch. CTX (5.8 and 18 nM) inhibited channel activity by 50 and 100%, respectively. Whole-cell outward K+ currents exhibited an early transient component which was blocked by CTX, and a delayed component which was insensitive to the toxin. The individual spikes evoked by glucose, recorded in the perforated-patch modality, were not affected by CTX (20 nM). Moreover, the frequency of slow oscillations in membrane potential, the frequency of action potentials and the rate of repolarization of the action potentials recorded from pancreatic islet beta-cells in the presence of glucose were not affected by CTX. We conclude that the K(Ca) does not participate in the steady-state glucose-induced electrical activity in rodent pancreatic islets.

Potassium permeability in pancreatic beta-cell. The effect of thiopental.

We studied the effects of the barbiturate thiopental on mouse beta-cell membrane potential and electrical activity under conditions where K+ permeability was stimulated by increases in cytosolic Ca2+. Thiopental (1 mM) antagonized the hyperpolarizing effect of increases in cytosolic Ca2+, increased either by exposure of islets to 50 mM K+ or by reduction of cellular ATP content by 2,4 dinitrophenol.

Cation transport by pancreatic beta-cells: effect of 4-aminopyridine on 86Rb+ and 45Ca2+ fluxes.

The effects of 4-aminopyridine (4-AP) on insulin release, glucose oxidation and 86Rb+ and 45Ca2+ fluxes of rat isolated islets were studied. 4-AP (0.1 and 1.0 mM) did not alter the 86Rb+ fractional efflux. However, 10 mM 4-AP significantly increased the 86Rb+ fractional efflux. 10 mM 4-AP also reduced the insulin release from islets incubated over 90 min in the presence of both 6 and 16.7 mM glucose and from perifused islet in the presence of 16.7 mM glucose. 4-AP (10 mM) only transiently increased the insulin release and the 45Ca2+ fractional efflux in the presence of 6 mM glucose. The 45Ca2+ fractional efflux was not changed when the islets were perifused at higher glucose concentration. At zero, 6 or 16.7 mM glucose, 4-AP (10 mM) significantly increased the 45Ca2+ net uptake by islets incubated for 90 min. 10 mM 4-AP significantly reduced the glucose oxidation of islets incubated for 120 min in the presence of 16.7 mM glucose. The effects of 10 mM 4-AP on the dynamics of insulin release and 86Rb+ fractional efflux were poorly reversible. In conclusion, 4-AP, at concentrations that did not alter the glucose metabolism, (0.1 and 1 mM), failed to affect the K+ permeability in beta-cells as judged by the measurements of 86Rb+ fractional efflux. At higher concentrations (10 mM) 4-AP increased 86Rb+ efflux, decreased glucose metabolism and reduced insulin release.

Thiopental inhibits K+ permeability of rat and mouse pancreatic beta-cells.

The effects of thiopental on the insulin release and 86Rb efflux from isolated rat islets and on parameters of the electrical activity of single beta-cells of mice were studied. Thiopental 0.2 and 1.0 mM increased by 16.6 and 33.3%, respectively, the insulin release induced by 6.0 mM glucose. Thiopental reduced the 86Rb efflux rate in both 0 and 6.0 mM glucose, but had only a slight effect in 16.7 mM glucose. Menadione (20 microM) did not block the inhibitory effect of thiopental on 86Rb efflux. Thiopental induced a reversible membrane depolarization in a dose-dependent manner (0.2-1.0 mM). It also induced electrical activity at a subthreshold glucose concentration and continuous spiking in presence of 11.1 mM glucose. In the presence of 2,4-dinitrophenol (20 microM) this continuous spiking was changed to an oscillatory activity similar to that induced by 11.1 mM glucose. Thiopental (0.5 mM) induced an increase in input resistance of 12.7, 17.9 and 16.0% in 0, 5.6 and 11.1 mM glucose, respectively. The thiopental-induced changes in insulin secretion, 86Rb efflux and electrical parameters indicate that K+ permeability was affected in both rat and mouse beta-cells. Our results suggest that thiopental is a direct inhibitor of the glucose-sensitive K+ permeability in the beta-cell.

Effect of temperature upon potassium-stimulated insulin release and calcium entry in mouse and rat islets.

The effect of cooling to 27 degrees C was studied in islets of Langerhans exposed to 5 and 50 mM potassium in the absence of glucose. Membrane potential and insulin release were measured simultaneously from microdissected mouse islets while 45Ca outflow and insulin release were measured from collagenase-isolated rat islets. Cooling inhibited potassium-induced insulin release in both preparations. However, calcium entry estimated from electrical records and from 45Ca outflow experiments was only slightly affected by decreasing the temperature to 27 degrees C. It is concluded that the inhibition of insulin release caused by cooling to 27 degrees C can, within limits, be dissociated from calcium influx.

Comparison of glucose-induced changes in electrical activity, insulin release, lactate output and potassium permeability between normal and ob/ob mouse islets: effects of cooling.

A comparison has been made between the glucose-induced changes in electrical activity, insulin release, lactate output and potassium permeability in normal and ob/ob obese (Norwich strain) mice. The electrical response of the islet membrane to high glucose (22.2 mmol/l) stimulation was different in the two types of mice, generating continuous spike activity in normal but producing bursts of activity in ob/ob mouse islets. The absolute amounts of insulin and lactate produced by ob/ob islets in response to both basal and high glucose concentrations were greater than the absolute amounts produced by normal islets, though the ratio of the amount produced in high glucose concentrations to the amount produced in basal glucose concentrations was not significantly different between normal and ob/ob islets for both parameters. Glucose-induced changes in potassium permeability were smaller in ob ob than in normal mice. Cooling from 37 to 27 degrees C, during steady-state glucose stimulation, reduced both lactate output and insulin release, the temperature coefficients being similar in both types of mice. The effect of temperature reduction on electrical activity was more marked in the islets of ob/ob mice than in those of normal mice; spike frequency was unaffected in normal but reduced in ob/ob mice, whereas spike amplitude was decreased in both. Cooling-induced inhibition of potassium permeability was greater in the islets of ob/ob mice than in those of normal mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrophysiological evidence for the inhibition of potassium permeability in pancreatic beta-cells by glibenclamide.

The effects of glibenclamide on the electrical activity of the beta-cells of the islets of Langerhans of normal mice have been investigated in the absence and presence of glucose (11.1 mM). Glibenclamide depolarized the cell membrane and this has been interpreted in terms of an increase in the ratio of the Na+ and K+ permeabilities, PNa/PK. This ratio increased from 0.05 to 0.24 in the presence of 4 microM glibenclamide and zero glucose. The input resistance of the beta-cells also increased. These observations indicate a decrease in K+ permeability. The effect is only slowly reversed after removal of glibenclamide. Uncouplers of oxidative phosphorylation do not reverse the depolarization induced by glibenclamide. It is suggested that glibenclamide is acting directly to inhibit the [Ca2+]i-gated K+ permeability in the beta-cell membrane.

Incidencia de gonorreia em populacao previdenciaria da Baixada Santista. / Gonorrhoea incidence in a social security population in Santos, Brazil

O estudo laboratorial sistematico (e independente do tipo de solicitacao do medico assistente) de 10.559 mulheres cuja queixa principal era de corrimento vaginal, revelou a seguinte frequencia dos patogenos pesquisados: Neisseria gonorrhoeae 2,9%, Trichomonas vaginalis 11,5% e Candida albicans 17,7%. Ressalta-se que na grande maioria dos casos que se revelaram como gonorreia, o medico assistente nao suspeitava do diagnostico e nao pedira exames especificos para esse patogeno. Sugere-se que em todos os casos de corrimento vaginal, a secrecao seja submetida a exame direto a fresco (pesquisa de Trichomonas vaginalis e leveduras), esfregaco corado pelo Gram (exame cuidadoso da lamina para pesquisa de diplococos Gram-negativos intracelulares, suspeitos de Neisseria gonorrhoeae e tambem de formas filamentosas de leveduras). A cultura em meios especificos fica assim reservada para os casos em que nao forem encontradas formas tipicas de Neisseria gonorrhoeae no esfregaco mesmo que nao haja suspeita de ser este o agente etiologico em questao. Pesquisa laboratorial de Chlamidia trachomatis e desejavel nos casos em que nao se isola nenhum outro patogeno