Intermittent sustained swimming in 'matrinxã' Brycon amazonicus (Bryconidae: Bryconinae): hematological and metabolic responses

In fish, studies on a wide variety of physiological effects of exercise have been reported since a long time. It has been attributed special attention to some types of exercise, however, its application as a healthful practice in the rearing and welfare of farming fish is rising in last few years. In this particular, long-term intermittent sustained swimming (ISS) has been not yet explored. In this work, the freshwater fish Brycon amazonicus was submitted to (ISS) for 30 days at velocity of 1.0 body-length sec-1 for 12h interspaced by 12h under still water. Hematology and metabolism were evaluated. Exercised fish decreased 30% the erythrocyte number and hemoglobin was unvaried. The stores of liver glycogen and muscular triacylglycerol (TAG) were increased and the metabolic profile was typically aerobic. The slight decrease of liver (TAG) plus the full metabolic and hematic trait allow investing in this kind of exercise a beneficial practice in the rearing of fish species.

Há muito tempo, tem sido relatada uma ampla variedade de efeitos fisiológicos em peixes sob exercício. Tem sido dada especial atenção a alguns tipos de exercício, mas, sua aplicação como prática salutar na criação e para o bem estar dos peixes vem crescendo nos últimos anos. Neste caso, a natação sustentada intermitente (ISS) por longos períodos ainda não foi explorada. Neste trabalho, o peixe de água doce Brycon amazonicus foi submetido a (ISS) por 30 dias à velocidade de 1,0 comprimento corporal s-1 por 12h intervalado de 12h sob regime de água sem movimento. A hematologia e o metabolismo foram avaliados. Os peixes exercitados diminuíram 30% a contagem de eritrócitos e o teor de hemoglobina permaneceu constante. Os estoques de glicogênio hepático, o teor de triacil glycerol muscular (TAG) aumentou e o perfil metabólico foi tipicamente aeróbico. O discreto aumento de TAG hepático, além das características hematológicas e do metabolismo como um todo, instiga-nos investigar este tipo de exercício como uma prática benéfica na criação de peixes.

Effect of melatonin supplementation on plasma glucose and liver glycogen levels in rats subjected to acute swimming exercise

The aim of the present study is to examine how melatonin supplementation affects plasma glucose and liver glycogen levels in rats subjected to acute swimming exercise. Spraque-Dawley species thirty adult male rats were allocated to 3 groups with equal number of animals: general control group which was not subjected to any procedure [Group 1], the group subjected to a 30-minute acute swimming exercise [Group 2], and the group subjected to a 30-minute acute swimming exercise after intraperitoneal [i.p.] melatonin supplementation [3 mg/kg/day] for 4 weeks [Group 3]. Blood samples collected from the experimental animals by decapitation method were analyzed in terms of plasma glucose, and glycogen levels were determined in liver tissue samples by histological method. The highest plasma glucose levels were obtained in group 2 [p<0,05]. Plasma glucose levels in groups 1 and 3 were not different. Mean liver glycogen level in group 3 was significantly higher than those in the other groups [p<0,01], while there was no significant difference between group 1 and group 2 in terms of this parameter. Results of the study demonstrate that melatonin supplementation can have a protective effect on liver glycogen reserves in rats subjected to acute swimming exercise

Association of diabetes and cigarette smoke exposure on the glycemia and liver glycogen of pregnant Wistar rats / Associação entre diabetes e exposição à fumaça de cigarro sobre a glicemia e glicogênio hepático de ratas Wistar prenhes

PURPOSE: To evaluate cigarette smoke exposure and/or diabetes association effects on the glycemia and liver glycogen levels of pregnant Wistar rats. METHODS: 60 adult rats were randomly distributed into (n=10/group): non-diabetic exposed to filtered air (G1); non-diabetic exposed to cigarette smoke only before pregnancy (G2); non-diabetic exposed to cigarette smoke before and during pregnancy (G3); diabetic exposed to filtered air (G4); diabetic exposed to cigarette smoke only before pregnancy (G5), and diabetic exposed to cigarette smoke before and during pregnancy (G6). Glycemia was determined at days 0 and 21 of pregnancy. Liver samples were collected for liver glycogen determinations. RESULTS: At day 21 of pregnancy, glycemia was higher in G5 and G6 compared to G4 group. G2 (2.43±0.43), G3 (3.20±0.49), G4 (2.62±0.34), G5 (2.65±0.27) and G6 groups (1.94±0.35) presented decreased liver glycogen concentrations compared to G1 (4.20±0.18 mg/100mg liver tissue) (p<0.05). G5 and G6 groups presented decreased maternal weight gain and litter weight. CONCLUSIONS: Severe diabetes and cigarette smoke exposure, alone or associated, caused impairment in liver glycogen storage at term pregnancy. Due to the fact that liver glycogen storages were considered determinant for glucose tolerance, it is relevant to point out a rigid clinical glycemic control and to stop smoking so earlier in pregnancy programming.

OBJETIVO: Avaliar a associação da exposição à fumaça de cigarro e/ou diabete sobre a glicemia e concentrações de glicogênio hepático em ratas Wistar prenhes. MÉTODOS: 60 ratas adultas foram distribuídas aleatoriamente em seis grupos (n=10/grupo): não-diabético exposto ao ar filtrado (G1); não-diabético exposto à fumaça de cigarro antes da prenhez (G2); não-diabético exposto à fumaça de cigarro antes e durante a prenhez (G3); diabético exposto ao ar filtrado (G4); diabético exposto à fumaça de cigarro antes da prenhez (G5); diabético exposto à fumaça de cigarro antes e durante a prenhez (G6). A glicemia foi determinada nos dias 0 e 21 de prenhez. Foram coletadas amostras de fígado para dosagens de glicogênio. RESULTADOS: No 21º dia de prenhez, a glicemia foi maior nos grupos G5 e G6 comparados ao grupo G4. Os grupos G2 (2,43±0,43), G3 (3,20±0,49), G4 (2,62±0,34), G5 (2,65±0,27) e G6 (1,94±0,35) apresentaram concentrações de glicogênio diminuídas comparados ao grupo G1 (4,20±0,18 mg/100mg) (p <0.05). Os grupos G5 e G6 apresentaram ganho de peso materno e peso da ninhada diminuídos. CONCLUSÕES: O diabete grave e a exposição à fumaça de cigarro, sozinhos ou associados, causaram prejuízo no armazenamento de glicogênio na prenhez a termo. Devido ao fato dos estoques de glicogênio serem determinantes para a tolerância à glicose, é imprescindível indicar um rígido controle glicêmico e deixar de fumar antes da gestação.

Avaliação do perfil lipídico, glicêmico, conteúdo de glicogênio hepático ecardíaco em ratos diabéticos suplementados com farinha de casca de maracujá (Passiflora edulis) / Assessment of the profile of lipids, glucose, liver and heart glucogen, in diabetic mice supplemented withpassion-fruit rind flour (Passiflora edulis) / Evaluación del perfil de lípidos, glucosa, contenido de glicógeno hepático y cardíaco, en ratones diabéticoscomplementados con harina de cáscara de maracuyá (Pasiflora edulis)

A ingestão de fibras alimentares está associada a redução do risco das complicações do diabetes mellitus, caracterizado pelos níveis elevados de glicose sangüínea. Com base nisto, o presente estudo propôs verificar o efeito da suplementação com farinha de casca de maracujá (Passiflora edulis) sobre os níveis plasmáticos de glicose, triglicérides, colesterol total e frações, e conteúdo de glicogênio hepático e cardíaco de ratos diabéticos. Utilizou-se 25 ratos, divididos em 5 grupos (n=5): grupo controle (GI) e grupo diabético (GII) que receberam ração comercial, dois grupos diabéticos tratados com ração suplementada com farinha de maracujá nas concentrações de 50 (GIII) e 100% (GIV) da dose correspondente à ingestão diária recomendada (IDR) de fibras, e grupo GV com ração suplementadacom 150% da IDR. Após o tratamento, coletou-se o plasma sangüíneo para análise dos parâmetros bioquímicos. No fígado e no coração, dosou-se o conteúdo de glicogênio. Em relação aos níveis lipídicos, não houve diferença significativa entre os grupos. A glicemia do GIII (137,60 ± 10,24 mg/dL)e GIV (153,60 ± 14,99 mg/dL) foi reduzida quando comparada ao GII (399,20 ± 37,21 mg/dL). O teor de glicogênio hepático e cardíaco, respectivamente, em GIII (22,91 ± 7,78 mg/g e 0,65 ± 0,09 mg/g)e GIV (28,29 ± 7,99 mg/g e 2,1 ± 0,19 mg/g) aumentou significativamente em relação ao GI (7,0 ± 4,71mg/g e 0,12 ± 0,01 mg/g), p<0,05. Conclui-se que a utilização da farinha de casca de maracujá nas concentrações de 50 e 100% da IDR foi efetiva para controle glicêmico e aumento do glicogênio hepático e cardíaco, não sendo efetiva na diminuição de lipídios plasmáticos no período de estudo.

The intake of alimentary fibers is associated to the reduction of the risk of complications with diabetes mellitus, which is characterized by high glucose levels in the blood. Based upon this,the present study aimed to check the effect of supplementation with passion fruit rind flour (Pasiflora edulis) on the glucose plasmatic levels, triglycerides, cholesterol total and fractions, and the hepatic and heart glucogen in diabetic mice. Twenty five mice were used, divided into 5 groups (n=5): control group (GI) and diabetic group (GII) which received commercial ration,two diabetic groups which received ration supplemented with passion fruit flour, 50% (GIII) and100% (GIV) concentrations of the recommended dose of daily fiber intake (RDI), and group(GV) having ration supplemented with 150% of the RDI. After the treatment, blood plasma was collected for the analysis of the biochemical parameters. The content of glucogen in the liver and the heart was quantified. In relation to the lipidic levels no significant difference was found among groups. The glucose level in GIII (137.60 + 10.24 mg/dL) and in GIV (153.60 + 14.99 mg/dL) was reduced when compared to GII (399.20 + 37.21 mg/dL). The level of hepatic and heart glucogen was significantly increased in GIII (22.91 + 7.71 mg/g and 0.65 + 0.09 mg/g) and GVI (28.29 + 7.99 mg/g) when compared to GI (7.0 + 4.71 mg/g and 0.12 + 0.01 mg/g), p<0.05. It was concluded that the use of flour from passion fruit rind in the concentrations of 50% and 100% was effective on the control of blood glucose and the increase of hepatic and heart glucogen, not being effective on the reduction of plasmatic lipids during the period of study.

La ingestión de fibras alimentares está asociada a la reducción del riesgo de complicaciones de la diabetes mellitus, caracterizada por elevados niveles de glucosa en la sangre. Con base en esto, el presente estudio se propuso verificar el efecto de la complementación con harina de cáscara de maracuyá (Pasiflora edulis) sobre los niveles plasmáticos de glucosa, triglicéridos, colesterol total y fracciones, y contenido de glicógeno hepático y cardíaco en ratones diabéticos. Se utilizaron 25 ratones, divididos en 5 grupos (n=5): grupo de controle (GI) y grupo diabético (GII) que recibieron ración comercial, dos grupos diabéticos tratados con ración complementada con harina de maracuyá, en las concentraciones de 50% (GIII) y 100% (IV) de la dosis correspondiente a la ingestión diaria recomendada (IDR) de fibras, y grupo (GV) con ración complementada con 150% de la IDR. Tras el tratamiento se colectó el plasma de la sangre para el análisis de los parámetros bioquímicos. En el hígado y en el corazón se ha dosificado el contenido de glicógeno. Con relación a los niveles lípidos no hubo diferencia significativa entre los grupos. La glicemia del GIII (137,60 + 10,24 mg/dL) y GIV (153,60 + 14,99 mg/dL)se ha reducido cuando comparada con GII (399,20 + 37,21 mg/dL). El contenido de glicógenohepático y cardíaco, respectivamente, en GIII (22,91 + 7,78 mg/g y 0,65 + 0,09 mg/g) y GIV(28,29 + 7,99 mg/g y 2,1 + 0,19 mg/g) ha aumentado significativamente con relación al GI (7,0+ 4,71 mg/g), p<0,05. Se ha concluido que la utilización de la harina de cáscara de maracuyá,en las concentraciones de 50% y 100% de la IDR, fue efectiva para el control de la glucosa y del aumento del glicógeno hepático y cardíaco, no resultando efectivo en la reducción de lípidos plasmáticos durante el periodo del estudio.

Thyroid dysfunction modulates glucoregulatory mechanism in rat.

The role of the thyroid gland in glucose homeostasis remains incompletely understood. To get a better insight hypo-and hyperthyroid conditions were experimentally induced in rat and found severe defects in glucose homeostasis. While blood glucose level returned to normal level after 2.5 hr of oral glucose challenge in control rats the blood glucose level remained high even after 24 hr of glucose load in both hypo- and hyperthyroid rats. These experimentally manipulated rats displayed higher levels of liver glycogen (10.45-22.8-fold) and serum glutamic pyruvic transaminase (1.48-9.8-fold). Liver histology of hyperthyroid treated rats revealed hepatotoxicity. From the results it can be concluded that thyroid gland plays an important role in glucose homeostasis.

Massive intestinal resection in rats fed up on glutamine: hepatic glycogen content valuation

RACIONAL: A glutamina tem sido utilizada amplamente no tratamento da síndrome do intestino curto e seus efeitos metabólicos são bem conhecidos no intestino delgado, porém pouco se tem relatado sobre seus efeitos no metabolismo hepático nessa condição. OBJETIVO: Verificar em modelo experimental, o efeito de dieta suplementada com glutamina administrada por via oral, em ratos submetidos a ressecção intestinal extensa, na evolução ponderal e no conteúdo de glicogênio hepático. MATERIAL E MÉTODOS: Ratos Wistar machos foram distribuídos em três grupos enterectomizados. As seguintes dietas foram utilizadas: com glutamina (grupo G), sem glutamina (grupo NG) e a dieta padrão do laboratório (grupo R). Em todos os animais a ressecção extensa do intestino delgado incluiu a válvula íleo-cecal. Após 20 dias os animais foram sacrificados. O fígado foi retirado para estudo histológico por microscopia ótica. As lâminas foram coradas pelo ácido periódico com base de Schiff com diastase. RESULTADOS: Todos os animais perderam peso entre o inicio e o final da pesquisa. Na comparação da perda média de peso expressa em percentagem, não houve diferença estatística em relação a essa variável. Nos grupos estudados o conteúdo de glicogênio no hepatócito, avaliado por método histológico, não diferiu estatisticamente. CONCLUSÕES: A oferta de glutamina por via oral não contribuiu para redução da perda de peso dos animais submetidos a ressecção intestinal extensa e não estimulou a síntese e armazenamento de glicogênio nos hepatócitos.

Preclinical evaluation of the antidiabetic effect of Eugenia jambolana seed powder in streptozotocin-diabetic rats

The world is facing an explosive increase in the incidence of diabetes mellitus and cost-effective complementary therapies are needed. The effects of Eugenia jambolana, a household remedy for diabetes, were studied. Streptozotocin diabetic female albino Wistar rats weighing 150-200 g (N = 6) were fed E. jambolana seed powder (250, 500 or 1000 mg/kg) for 15 days. Diabetic rats fed 500 and 1000 mg/kg seed powder showed an increase in body weight on day 20 in relation to day 5 (6 ± 4.7, 9 ± 7.8 vs diabetic control -16 ± 7.1 g, P < 0.001), a decrease in fasting blood glucose (75 ± 11.9, 123 ± 14.4 vs diabetic control -34 ± 12.1 mg/dl, P < 0.001), a difference in post-treatment fasting and peak blood glucose (38 ± 11.9, 36 ± 14.2 vs diabetic control 78 ± 11.9 mg/dl, P < 0.001), and a difference in liver glycogen (50 ± 6.8, 52 ± 7.5 vs normal control 90 ± 6.6 æg/g of liver tissue, P < 0.001). Tri-terpenoids, tannins, gallic acid, and oxalic acid were the chemical constituents detected in E. jambolana seed. The best results were obtained with an oral dose of 500 mg/kg. Subacute toxicity studies with a single administration of 2.5 and 5.0 g/kg seed powder showed no mortality or abnormality. These data on the antidiabetic effect of E. jambolana seed are adequate for approval of phase 2 clinical trials to evaluate this seed powder as complementary therapy in type 2 and type 1 diabetes.

Hyperglycemic effect of low protein cassava diet.

Hyperglycemic effect of cassava diet in presence of varying amounts of protein has been carried out. The rats fed a low protein high cyanide diet showed an increase in the blood glucose and a decrease in the liver glycogen. The activity of glycogen phosphorylase, glucose 6-phosphatase and phosphoglucomutase showed higher levels in the liver of low protein high cyanide group compared to the control group. Also, the activity of hexokinase, and isocitrate dehydrogenase activity in the liver of high cyanide low protein were significantly low. The results suggests that cassava diet with the low protein can induce hyperglycemia.

Metabolic changes induced by reperfusion after warm liver ischemia

Experimental studies have demonstrated a decrease in hepatocyte transmembrane potential (HTP) during ischemia, whereas HTP is improved in livers with greater glycogen reserves. The present study was undertaken to assess blood glucose. pH, K+ and hepatic glycogen levels during determined periods of warm liver ischemia and after reperfusion. The study was conducted on 15 mongrel dogs (9-17 kg) submitted to warm liver ischemia by clamping of the portal vein and hepatic artery (90 ñ 20 min) with blood flow of the infradiaphragmatic region shunted into left external jugular vein through a venovenous bypass draining the portal vein and the inferior vena cava. Blood samples and hepatic tissue biopsies were obtained before ischemia (control), after 15 and 45 min of ischemia, and 15 min after liver reperfusion. A significant increase in blood glucose was observed during reperfusion of the liver (p < O.05 vs control, 15 and 45 min of ischemia). The period of ischemia had a progressive glycogenolysis which became more marked after reperfusion, possibly explaining the increase in blood glucose levels observed during this period.

Effect of leaf extract of Aegle marmelose in diabetic rats.

Alloxan induced animal model was used to evaluate the potential antidiabetic effect of A. marmelose leaf extract. The diabetic animals were given insulin injection and another group A. marmelose leaf extract orally. It maintained the weight of the animals near to the control rats but a significant decrease in weight was noted in diabetic animals without any treatment. The blood glucose level in treated animals were near to that of control ones. Also a significantly increased glucose tolerance was observed in animals orally given the leaf extract prior to the experiment. A significant decrease in liver glycogen (1.24 +/- .07 g/100 g of wet tissue) was observed in diabetic rats which was brought to almost the normal level (1.84 +/- .14 g/100 g) with leaf extract treatment. Blood urea and serum cholesterol increased (62.66 +/- 3.50 and 192.67 +/- 13.64 mg/dl) significantly in alloxan diabetic rats. The leaf extract treatment decreased the blood urea and serum cholesterol (37.83 +/- 3.97 and 99.20 +/- 8.43 mg/dl) to that of control ones. A similar effect was seen with insulin treatment. The results indicate that the active principle in A. marmelose leaf extract has similar hypoglycaemic activity to insulin treatment.

Developmental changes in blood glucose and tissue carbohydrates in the fetal rat: effects of insulin and adrenaline

The ontogeny of glucose regulation was studied in the rat by measuring the levels of plasma glucose, tissue glucose and tissue glycogen from fetal day 15 (E15) to adulthood. Since insulin and adrenaline are important glucose regulators in the adult, we also tested the effects of these hormones on above variables. The main findings are the following: 1) Umbilical blood glucose was very low (25 mg/100 ml) from E15 to E19, increasing to 66 mg/ml by E21 but still below maternal levels (110 mg/100 ml). 2) Umbilical venous-arterial (VEN-ART) glucose differences were very small (1 mg/100 ml) from E15 to E17, increased to 6 mg/100 ml by E19, but dropped again becoming negative (-l5 mg/100 ml) just before birth when umbilical arterial blood glucose rose above venous blood glucose. 3) Glucose and glycogen concentrations rose drastically in liver towards the end of gestation. 4) Tissue glycogen and, to a much lesser degree, glucose, fell after birth to rise again in adulthood. 5) Insulin injection caused an increase in liver glycogen from E17 onwards, and also increased glycogen in brain and placenta on E19. However, insulin decreased glycogen in brain and kidney by E21. 6) Adrenaline caused an increase in the umbilical venous-arterial glucose difference at E15 and E17 with a concomitant increase in liver, brain and heart glycogen at E15. By E21 the response of liver glycogen to adrenaline was drastically reversed. Our data suggest that the mechanism regulating glucose homeostasis changes half way through fetal development. Tissue self-regulation is replaced with a centralized mechanism similar to that of the adult. This occurs just before birth as the liver becomes a reservoir for carbohydrates and responsive to insulin and adrenaline

Long-term treatment with 2,5-hexanedione has no effect on the specific activity of some brain and liver glycolytic enzymes of adult rats

Prolonged exposure to hexacarbon compounds is neurotoxic to humans and animals. As various hexacarbon compounds inhibit glycolytic enzymes in vitro, it has been suggested that this may underlie their neurotoxic effects in vivo. in the present investigation we examined whether long-term treatment with 2,5-hexanedione (200 mg/kg, sc) for 40 days affects the specific activity of brain and liver enolase, lactic dehydrogenase and malate dehydrogenase in female Wistar rats (150-170 g). Glycemia and liver glycogen levels were also determined. The specific activity of all enzymes tested, liver glycogen content and glycemia were not affected by chronic treatment with 2,5-hexanedione. Rats treated with 2,5-hexanedione weighed significantly less than control rats starting on day 18 of treatment (183 ñ 3.4G for the vehicle groups vs 171 ñ 3.2G for the 2,5-hexanedione group). 2,5-hexanedione also increased water intake (46 por cento when compared to vehicle-treated rats). prolonged treatmentof rats with the non-neurotoxic hexacarbon 1,6-hexanediol (207 mg/kg, sc) significantly increased liver glycogen content (5.9 ñ 0.6g/100g for the vehicle group vs 9.0 ñ 1.1g/100 g for the 1.6-hexanediol group) as well as food intake (44.0 ñ 1.5g 100g-1 6 days-1 for thge 1,6-hexanediol group). These results indicate that long-term treatment with 2,5-hexanedione did not alter the brain and liver glycolytic enzymes studied, liver glycogen content or glycemia but did reduce weight gain and increased water intake, whereas the administration of the reportedly non-neurotoxic hexacarbon 1,6-hexanediol has demonstrable metabolic effects

Influence of parathyroidectomy on liver glycogen in rats treated with carbon tetrachloride.

Carbon tetrachloride (CCl4) brings about a rise in cytosolic free calcium which may lead to glycogen mobilization. Therefore, glycogen and glucose-6-phosphatase (G-6-pase) levels in the liver of parathyroidectomized (PTX) rats following CCl4 treatment have been estimated. CCl4 depletes both glycogen and G-6-pase levels in the liver. PTX followed by CCl4 administration, however, fails to restore liver glycogen and G-6-pase levels. The results suggest that neither cytosolic Ca2+ nor phospholipase A2 mediation is needed for glycogen mobilization, however, glucocorticoid intervention might have a role in such mechanisms.

Hypoglycemic activity of Swertia chirayita (Roxb ex Flem) Karst.

Hexane fraction of S. chirayita (250 mg/kg body wt.) induced significant fall in blood sugar and significant increase in plasma IRI simultaneously after single oral administration without influencing liver glycogen concentration in albino rats. On the other hand, daily administration for 28 days resulted in significant lowering of blood sugar and increase in plasma IRI along with a significant rise in liver glycogen. Intestinal absorption of glucose was not inhibited by hexane fraction. It is suggested that hexane fraction of S. chirayita possibly acts through its insulin releasing effect.