Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 24
Filter
1.
Braz J Med Biol Res ; 51(5): e7057, 2018 Mar 26.
Article in English | MEDLINE | ID: mdl-29590261

ABSTRACT

The aim of this study was to investigate the effect of lactatemia elevation and glycemia reduction on strenuous swimming performance in fasted rats. Three rats were placed in a swimming tank at the same time. The first rat was removed immediately (control group) and the remaining ones were submitted to a strenuous swimming session. After the second rat was exhausted (Exh group), the third one was immediately removed from the water (Exe group). According to the period of time required for exhaustion, the rats were divided into four groups: low performance (3-7 min), low-intermediary performance (8-12 min), high-intermediary performance (13-17 min), and high performance (18-22 min). All rats were removed from the swimming tanks and immediately killed by decapitation for blood collection or anesthetized for liver perfusion experiments. Blood glucose, lactate, and pyruvate concentrations, blood lactate/pyruvate ratio, and liver lactate uptake and its conversion to glucose were evaluated. Exhaustion in low and low-intermediary performance were better associated with higher lactate/pyruvate ratio. On the other hand, exhaustion in high-intermediary and high performance was better associated with hypoglycemia. Lactate uptake and glucose production from lactate in livers from the Exe and Exh groups were maintained. We concluded that there is a time sequence in the participation of lactate/pyruvate ratio and hypoglycemia in performance during an acute strenuous swimming section in fasted rats. The liver had an important participation in preventing hyperlactatemia and hypoglycemia during swimming through lactate uptake and its conversion to glucose.


Subject(s)
Hypoglycemia/physiopathology , Lactic Acid/blood , Liver/physiopathology , Pyruvic Acid/blood , Swimming/physiology , Animals , Blood Glucose/analysis , Fasting/physiology , Hypoglycemia/blood , Hypoglycemia/metabolism , Male , Perfusion , Physical Conditioning, Animal/physiology , Rats , Rats, Wistar , Time Factors
2.
Arq. bras. med. vet. zootec. (Online) ; 69(5): 1089-1096, set.-out. 2017. ilus, tab
Article in Portuguese | LILACS, VETINDEX | ID: biblio-876985

ABSTRACT

Informações sobre a vascularização da parede folicular e do corpo lúteo equino, associadas à superovulação, são escassas. Com o objetivo de avaliar o efeito superovulatório do extrato de pituitária equina (EPE) no fluxo sanguíneo folicular e luteal, foram utilizadas seis éguas Puro Sangue Árabe, em dois ciclos estrais (controle e tratamento). As éguas foram monitoradas diariamente por ultrassonografia modo B, até que os folículos atingissem diâmetro de 23mm (desvio). No ciclo tratamento, as éguas receberam 8mg de EPE, uma vez ao dia, por via IM, até que dois ou mais folículos atingissem o diâmetro entre 32 e 35mm. A ovulação foi induzida com acetato de deslorelina, quando os folículos atingiram, no mínimo, 35mm. No momento do desvio folicular, da indução da ovulação e do último exame pré-ovulatório, foi utilizada a ultrassonografia modo B para medir o diâmetro dos folículos e, no oitavo dia pós-ovulação, para a área do corpo lúteo (CL). Utilizou-se também ultrassonografia com Doppler colorido para avaliar a perfusão sanguínea da parede folicular e do parênquima luteal. No ciclo controle, foi realizado o mesmo procedimento, exceto pelo uso do EPE. Os dados foram submetidos à análise de variância, com nível de significância de 5%. Não foi observado efeito do EPE sobre o número de ovulações, o diâmetro dos folículos, a vascularização da parede folicular e a concentração sérica de estrógeno. Os animais, tratados ou não, apresentaram CLs funcionais, não havendo diferença na área do parênquima ou da vascularização luteal, nem na concentração sérica de progesterona, no oitavo dia após a ovulação. Foi observado que o EPE proporcionou um maior número de folículos subordinados no momento da indução da ovulação do folículo dominante (P ≤ 0,05). Embora esses folículos não tenham chegado a ovular, concluiu-se que o EPE atuou no crescimento de folículos, que podem ser utilizados em outras biotécnicas, como a transferência de oócitos, com maior aproveitamento da reserva folicular de ovários equinos.(AU)


Knowledge about follicle and corpus luteum vascularization associated with superovulation in mares is scarce. Aiming to evaluate the effect of equine pituitary extract (EPE) on superovulation, the experiment was conducted using six mares Purebred Arabian in two estrous cycles (control and treatment). The mares were synchronized, and monitored daily by ultrasound B mode until the follicles reached diameter ≤ 23 mm (deviation). In the treatment cycle, from the deviation, mares received 8 mg of EPE, once a day, intramuscularly, until two or more follicles reached a diameter between 32 and 35 mm. Ovulation was induced with deslorelin acetate when follicles reached at least 35 mm. At the time of follicular deviation, induction of ovulation and final preovulatory exam, it was used B-mode ultrasound to measure the diameter of follicles and on the eighth day after ovulation to measure the area of the corpus luteum (CL); color Doppler was also used to assess blood perfusion of the follicle wall and luteal parenchyma. In the control cycle was performed the same procedure except for the use of EPE. Data were subjected to analysis of variance, with 5% significance level. There was no effect of EPE on ovulation number, diameter of follicles, vascularity of the follicular wall and serum estrogen concentration. The animals treated or not, showed functional CLs, with no difference in parenchymal area or luteal vascularization, or in serum progesterone concentration on the eighth day after ovulation. It was observed that the EPE provided a greater number of subordinate follicles at the time of induction of ovulation of the dominant follicle. Although these follicles have failed to ovulate, it was concluded that EPE influenced the follicles growth, and it can be used in other biotechnologies, with greater utilization of equine ovarian follicular reserve.(AU)


Subject(s)
Animals , Female , Corpus Luteum/blood supply , Corpus Luteum/diagnostic imaging , Horses/physiology , Ovarian Follicle/blood supply , Ovarian Follicle/diagnostic imaging , Regional Blood Flow/physiology , Superovulation , Ultrasonography, Doppler, Color/veterinary
3.
Andrologia ; 49(3)2017 Apr.
Article in English | MEDLINE | ID: mdl-27251095

ABSTRACT

This work aimed to evaluate the effect of stabilisation times, glycerol concentration, and the catalase and superoxide dismutase supplementation of diluent on parameters of frozen-thawed spermatozoa from epididymis of Nelore bulls: Experiment 1: spermatozoa diluted in Tris-egg yolk with glycerol (3%, 5% or 7%) and stabilisation times (0, 2 or 4 hr at 5°C); Experiment 2: Tris-egg yolk only, Tris-egg yolk with catalase (CAT, 50 or 100 U ml-1 ) or superoxide dismutase (SOD, 50 or 100 U ml-1 ). Frozen-thawed spermatozoa were evaluated for kinetic parameters, plasma membrane and acrosome integrity, mitochondrial activity and IVF capacity. ALH and BCF were affected (p < .05) by glycerol at 3% after 4-hr equilibration time and 7% after 2-hr equilibration time. Glycerol 3% had lower (p < .05) iPM and iAc after 4 hr. Glycerol 5% had greater (p < .05) hPMM after 4 hr and iAc after 2 hr than at 0 hr. SOD 100 U ml-1 had lower (p < .05) linearity and wobble compared to control group. No was observed differences to fertilisation rate (p < .05) among groups. In conclusion, glycerol 5% in Tris-egg yolk extender for 4 hr is suitable for the preservation of sperm kinetics and membrane integrity. CAT (50 and 100 U ml-1 ) or SOD (50-100 U ml-1 ) had no beneficial effects on sperm kinetics, plasma and acrosomal membrane integrity, mitochondrial activity or the capacity for IVF of frozen-thawed spermatozoa from epididymis of Nelore bulls.


Subject(s)
Antioxidants/pharmacology , Cryoprotective Agents/pharmacology , Epididymis/cytology , Glycerol/pharmacology , Insemination, Artificial/veterinary , Semen Preservation/veterinary , Specimen Handling/veterinary , Spermatozoa/drug effects , Animals , Catalase/pharmacology , Cattle , Cryopreservation/veterinary , Freezing/adverse effects , Male , Sperm Motility/drug effects , Superoxide Dismutase/pharmacology , Time Factors
4.
Arq. bras. med. vet. zootec ; 68(5): 1237-1243, set.-out. 2016. tab
Article in English | LILACS, VETINDEX | ID: biblio-827888

ABSTRACT

The aim of this study was to evaluate the effect of different concentrations of trans-resveratrol or quercetin on the ability of goat sperm to withstand being frozen. Six pools of semen obtained from six male goats were processed with different concentrations of resveratrol or quercetin (Experiment 1: 0, 15, 25, 50, 75 or 100µM resveratrol; Experiment 2: 0, 15, 25, 50, 75 or 100µM quercetin) and frozen. After thawing, the semen was evaluated for sperm kinematics, plasma membrane and acrosome integrity, morphology and oxidative stress following 0 and 1h of incubation. Immediately after thawing (0h), wobble (oscillation index) in the groups treated with 100µM of quercetin or resveratrol was lower (P<0.05) than in those treated with 0 and 25µM resveratrol and 0µM quercetin, respectively. After 1h of incubation, the total motility in treatments with 15, 50 and 75µM quercetin, as well as the plasma membrane integrity in all quercetin concentrations were lower (P<0.05) than at 0h. In opposition, the linearity of semen samples treated with 100µM quercetin and the straightness of those treated with 75 and 100µM quercetin were lower (P<0.05) at 0h than at 1h after thawing. Thus, it can be concluded that resveratrol and quercetin at high concentrations (100µM) transiently reduce the wobble of goat sperm submitted to frozen storage, and that quercetin (75 and 100µM) increases the linearity and straightness over time, which can be favorable for fertility.(AU)


O objetivo deste estudo foi avaliar o efeito de diferentes concentrações de transresveratrol ou quercetina sobre a capacidade dos espermatozoides caprinos de resistirem à congelação. Seis pools de sêmen, obtidos de seis reprodutores caprinos, foram processados com diferentes concentrações de resveratrol ou quercetina (Experimento 1: 0, 15, 25, 50, 75 ou 100µM de resveratrol; Experimento 2: 0, 15, 25, 50, 75 ou 100µM de quercetina) e congelados. Após o descongelamento, o sêmen foi avaliado quanto à cinética espermática, à integridade das membranas plasmática e acrossomal, à morfologia e ao estresse oxidativo nos tempos zero e uma hora de incubação. Imediatamente após a descongelação (zero hora), o wobble (índice de oscilação) nos grupos tratados com 100µM de quercetina ou de resveratrol foi menor (P<0,05) do que nos tratados com 0 e 25µM de resveratrol e com 0µM de quercetina, respectivamente. Após uma hora de incubação, a motilidade total dos tratamentos com 15, 50 e 75µM de quercetina, assim como a integridade de membrana plasmática em todas as concentrações de quercetina, foi menor (P<0,05) do que à zero hora. Em oposição, a linearidade das amostras de sêmen tratadas com 100µM de quercetina e a retilinearidade daquelas tratadas com 75µM e 100µM de quercetina foram menores (P<0,05) à zero hora do que à uma hora após descongelação. Assim, pode-se concluir que o resveratrol e a quercetina, em concentrações elevadas (100µM), reduzem, transitoriamente, o índice de oscilação de espermatozoides caprinos submetidos à congelação e que a quercetina (75 e 100µM) aumenta a linearidade e a retilinearidade ao longo do tempo, o que pode ser favorável à fertilidade.(AU)


Subject(s)
Animals , Male , Flavonoids/analysis , Quercetin/analysis , Ruminants , Semen Preservation/veterinary , Antioxidants , Cryopreservation/veterinary , Oxidative Stress
6.
Genet Mol Res ; 11(3): 2598-607, 2012 Aug 16.
Article in English | MEDLINE | ID: mdl-22869085

ABSTRACT

Papillomaviruses are known to cause benign or malignant lesions in various animals. In cattle, bovine papillomavirus (BPV) is the etiologic agent of papillomatosis and neoplasia of the upper gastrointestinal tract and urinary bladder. Currently, there are no standard diagnostic tests or prophylactic vaccines. Protection against papillomavirus infection is conferred by neutralizing antibodies directed towards the major structural protein L1. These antibodies can be efficiently induced by immunization with virus-like particles that are formed spontaneously after L1 gene expression in recombinant systems. The yeast Pichia pastoris is known to provide an efficient system for expression of proteins due to reduced cost and high levels of protein production. We evaluated P. pastoris for expression of the L1 gene from BPV1, BPV2 and BPV4. After methanol induction, the recombinants were able to produce L1 proteins of the three different BPV types. To increase heterologous L1 protein levels, a codon optimization strategy was used for production under bioreactor conditions. The BPV1 L1 protein was identified by monoclonal antibody anti-6xHis. This is the first report of BPV L1 expression in yeast.


Subject(s)
Bovine papillomavirus 1/genetics , Capsid Proteins/genetics , Gene Expression , Genes, Viral/genetics , Pichia/metabolism , Animals , Blotting, Western , Bovine papillomavirus 4/genetics , Capsid Proteins/metabolism , Cattle , Codon/genetics , Electrophoresis, Polyacrylamide Gel , Gene Expression Regulation, Viral , Recombination, Genetic/genetics , Reverse Transcriptase Polymerase Chain Reaction
7.
Theor Appl Genet ; 112(2): 298-314, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16307229

ABSTRACT

Sugarcane (Saccharum spp.) is a clonally propagated outcrossing polyploid crop of great importance in tropical agriculture. Up to now, all sugarcane genetic maps had been developed using either full-sib progenies derived from interspecific crosses or from selfing, both approaches not directly adopted in conventional breeding. We have developed a single integrated genetic map using a population derived from a cross between two pre-commercial cultivars ('SP80-180' x 'SP80-4966') using a novel approach based on the simultaneous maximum-likelihood estimation of linkage and linkage phases method specially designed for outcrossing species. From a total of 1,118 single-dose markers (RFLP, SSR and AFLP) identified, 39% derived from a testcross configuration between the parents segregating in a 1:1 fashion, while 61% segregated 3:1, representing heterozygous markers in both parents with the same genotypes. The markers segregating 3:1 were used to establish linkage between the testcross markers. The final map comprised of 357 linked markers, including 57 RFLPs, 64 SSRs and 236 AFLPs that were assigned to 131 co-segregation groups, considering a LOD score of 5, and a recombination fraction of 37.5 cM with map distances estimated by Kosambi function. The co-segregation groups represented a total map length of 2,602.4 cM, with a marker density of 7.3 cM. When the same data were analyzed using JoinMap software, only 217 linked markers were assigned to 98 co-segregation groups, spanning 1,340 cM, with a marker density of 6.2 cM. The maximum-likelihood approach reduced the number of unlinked markers to 761 (68.0%), compared to 901 (80.5%) using JoinMap. All the co-segregation groups obtained using JoinMap were present in the map constructed based on the maximum-likelihood method. Differences on the marker order within the co-segregation groups were observed between the two maps. Based on RFLP and SSR markers, 42 of the 131 co-segregation groups were assembled into 12 putative homology groups. Overall, the simultaneous maximum-likelihood estimation of linkage and linkage phases was more efficient than the method used by JoinMap to generate an integrated genetic map of sugarcane.


Subject(s)
Chromosome Mapping/methods , Crosses, Genetic , Genetic Linkage , Likelihood Functions , Saccharum/genetics , Chromosome Segregation , Genetic Markers/genetics , Polymorphism, Restriction Fragment Length
8.
Braz. j. med. biol. res ; 34(6): 771-7, Jun. 2001. tab, graf
Article in English | LILACS | ID: lil-285852

ABSTRACT

Hepatic responsiveness to gluconeogenic substrates during insulin-induced hypoglycemia was investigated. For this purpose, livers were perfused with a saturating concentration of 2 mM glycerol, 5 mM L-alanine or 5 mM L-glutamine as gluconeogenic substrates. All experiments were performed 1 h after an ip injection of saline (CN group) or 1 IU/kg of insulin (IN group). The IN group showed higher (P<0.05) hepatic glucose production from glycerol, L-alanine and L-glutamine and higher (P<0.05) production of L-lactate, pyruvate and urea from L-alanine and L-glutamine. In addition, ip injection of 100 mg/kg glycerol, L-alanine and L-glutamine promoted glucose recovery. The results indicate that the hepatic capacity to produce glucose from gluconeogenic precursors was increased during insulin-induced hypoglycemia.


Subject(s)
Animals , Male , Rats , Gluconeogenesis , Hypoglycemia/metabolism , Liver/metabolism , Alanine/blood , Alanine/pharmacology , Blood Glucose/analysis , Cryoprotective Agents/pharmacology , Gluconeogenesis/drug effects , Glucose/biosynthesis , Glutamine/blood , Glutamine/pharmacology , Glycerol/blood , Glycerol/pharmacology , Hypoglycemia/chemically induced , Insulin/adverse effects , Lactic Acid/biosynthesis , Liver/drug effects , Pyruvic Acid/metabolism , Rats, Wistar , Urea/metabolism
9.
Braz J Med Biol Res ; 34(6): 771-7, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11378667

ABSTRACT

Hepatic responsiveness to gluconeogenic substrates during insulin-induced hypoglycemia was investigated. For this purpose, livers were perfused with a saturating concentration of 2 mM glycerol, 5 mM L-alanine or 5 mM L-glutamine as gluconeogenic substrates. All experiments were performed 1 h after an ip injection of saline (CN group) or 1 IU/kg of insulin (IN group). The IN group showed higher (P<0.05) hepatic glucose production from glycerol, L-alanine and L-glutamine and higher (P<0.05) production of L-lactate, pyruvate and urea from L-alanine and L-glutamine. In addition, ip injection of 100 mg/kg glycerol, L-alanine and L-glutamine promoted glucose recovery. The results indicate that the hepatic capacity to produce glucose from gluconeogenic precursors was increased during insulin-induced hypoglycemia.


Subject(s)
Gluconeogenesis/drug effects , Hypoglycemia/metabolism , Liver/drug effects , Alanine/blood , Alanine/pharmacology , Animals , Blood Glucose/analysis , Cryoprotective Agents/pharmacology , Glucose/biosynthesis , Glutamine/blood , Glutamine/pharmacology , Glycerol/blood , Glycerol/pharmacology , Hypoglycemia/chemically induced , Hypoglycemic Agents , Insulin , Lactic Acid/biosynthesis , Liver/metabolism , Male , Pyruvic Acid/metabolism , Rats , Rats, Wistar , Urea/metabolism
10.
Res Commun Mol Pathol Pharmacol ; 110(3-4): 264-72, 2001.
Article in English | MEDLINE | ID: mdl-12760493

ABSTRACT

The purpose of the present study was to investigate the effect of the combined administration of hepatic gluconeogenic substrates (glycerol + L-lactate + L-alanine + L-glutamine) on glucose recovery during insulin induced hypoglycemia (IIH), in rats. IIH was obtained by an ip injection of regular insulin (1 U/kg). Thus, 150 min after insulin administration the rats received an ip injection of glycerol + L-lactate + L-alanine + L-glutamine (each 100 mg/kg). In these experiments control groups, which received saline, glucose or isolated precursors (100 mg/kg), were employed. Glycemia was measured 30 min later, i.e., 180 min after insulin injection. The results showed that the combined administration of gluconeogenic precursors is more efficient than that of glucose itself to promote glycemia recovery. Since, the blood levels of hepatic glucose precursors were decreased (glycerol, L-lactate and L-alanine) or maintained (L-glutamine) during IIH, the ability of the liver to produce glucose from these gluconeogenic substrates was investigated. The results showed that the maximal capacity of the liver to produce glucose from glycerol (2 mM), L-lactate (2 mM), L-alanine (5 mM) and L-glutamine (5 mM) was increased. To L-alanine and L-glutamine, not only the glucose production was increased (P < 0.05) but also the production of L-lactate, pyruvate and urea. Therefore, the results suggest that the decreased availability of glucose precursors, promoted by insulin administration, limits the participation of hepatic gluconeogenesis to glycemia recovery. However, the administration of gluconeogenic precursors could overcome this limitation and promote better glycemia recovery than glucose itself.


Subject(s)
Glucose/therapeutic use , Hypoglycemia/drug therapy , Liver/drug effects , Alanine/administration & dosage , Alanine/blood , Alanine/therapeutic use , Animals , Blood Glucose , Drug Combinations , Glycerol/administration & dosage , Glycerol/blood , Glycerol/therapeutic use , Lactic Acid/administration & dosage , Lactic Acid/blood , Lactic Acid/therapeutic use , Liver/metabolism , Male , Rats , Rats, Wistar
12.
Int J Obes Relat Metab Disord ; 23(11): 1207-12, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10578212

ABSTRACT

OBJECTIVE: To investigate whether leptin interferes directly with glycogenolysis and gluconeogenesis in isolated rat hepatocytes and also in in situ rat perfused livers. ANIMALS: Male albino rats (200-250 g) were used in all experiments. MEASUREMENTS: D-glucose, L-lactate and pyruvate production. RESULTS: In the present study, no differences were found for the rates of glycolysis, as expressed by the areas under the curves, among control (24.2+5.0 mmol¿g), leptin (32.0+4.5 mmol¿g), glucagon (24.7+3.0 mmol¿g), and the leptin + glucagon (23.8+3.4 mmol¿g) groups. No difference was found for the rates of glycogenolysis between the control and the leptin perfused livers (15.2+3.9 and 15.0+3.2 mmol¿g, respectively). In the presence of glucagon, the areas under the curves for the rate of glycogenolysis rose to 108.6+3.8 mmol¿g. When leptin was combined with glucagon, the area under the curve for glycogenolysis was 43. 7+4.3 mmol¿g. In fact, leptin caused a reduction of almost 60% (P<0. 001) in the rate of glucagon-stimulated glycogenolysis. Under basal conditions, the addition of leptin (100 ng¿ml) to the incubation medium did not elicit any alteration in glucose production by isolated hepatocytes. However, in the presence of leptin, the production of glucose from glycerol (2 mM), L-lactate (2 mM). L-alanine (5 mM) and L-glutamine (5 mM) by the isolated hepatocytes was significantly reduced (30%, 30%, 23% and 25%, respectively). The rate of glucose production (glycogenolysis) by isolated hepatocytes was not different between the control and the leptin incubated groups (445.0+/-91.0 and 428.0+/-72.0 nmol¿106 cells¿h, respectively). CONCLUSION: We conclude that leptin per se does not directly affect either liver glycolysis or its glucose production, but a physiological leptin concentration is capable of acutely inducing a direct marked reduction on the rate of glucagon-stimulated glucose production in in situ rat perfused liver. Leptin is also capable of reducing glucose production from different gluconeogenic precursors in isolated hepatocytes.


Subject(s)
Glucose/metabolism , Leptin/pharmacology , Liver/drug effects , Liver/metabolism , Alanine/metabolism , Animals , Glucagon/pharmacology , Gluconeogenesis/drug effects , Glutamine/metabolism , Glycerol/metabolism , Glycogen/metabolism , Lactic Acid/metabolism , Male , Rats , Rats, Wistar
13.
Zhongguo Yao Li Xue Bao ; 20(12): 1083-6, 1999 Dec.
Article in English | MEDLINE | ID: mdl-11189196

ABSTRACT

AIM: To investigate the hepatic capacity to produce glucose during hypoglycemia induced by insulin (HII). METHODS: Livers from 24-h fasted rats which received i.p. insulin (HII rats) or saline (control rats) were perfused in situ. The gluconeogenic substrates L-alanine (5 mmol/L), L-glutamine (5 mmol/L), L-lactate (2 mmol/L), and glycerol (2 mmol/L) were employed. The gluconeogenic activity was measured as the difference between rates of glucose released during and before the substrate infusion. In part of the experiments the production of urea was measured. Before the liver perfusion blood was collected for determination of glycemia and insulinemia. RESULTS: HII rats showed: (a) hypoglycemia and hyperinsulinemia; (b) increased hepatic capacity to produce glucose from L-alanine and L-glutamine; (c) increased hepatic ureogenesis from L-alanine and L-glutamine; and (d) increased hepatic glucose production from glycerol. However, hepatic glucose production from L-lactate was not affected by hypoglycemia. CONCLUSION: In spite of hyperinsulinemia the hepatic capacity to produce glucose from L-glutamine and L-alanine increased during HII. These results can be attributed to the higher hepatic catabolism of both amino acids, since the ability of the liver to produce glucose was not affected by hypoglycemia.


Subject(s)
Gluconeogenesis , Glucose/metabolism , Hypoglycemia/metabolism , Liver Glycogen/metabolism , Liver/metabolism , Alanine/metabolism , Animals , Glutamine/metabolism , Hypoglycemia/chemically induced , Insulin , Male , Rats , Rats, Wistar
14.
Res Commun Mol Pathol Pharmacol ; 102(2): 113-23, 1998 Nov.
Article in English | MEDLINE | ID: mdl-10100503

ABSTRACT

The participation of hepatic glycogenolysis and gluconeogenesis to the glycemic changes promoted by exercise was investigated. For this purpose, we employed swimming rats (2.5% body weight extra load attached to the tail, at 24 degrees C) using a favorable condition to measure hepatic glycogenolysis (fed rats) and a favorable condition to measure hepatic gluconeogenesis (fasted rats). This experimental approach permits us to compare the contribution of hepatic glycogenolysis and gluconeogenesis to glucose changes for a specific schedule of exercise. The animals were investigated at rest, after 5 minutes of swimming and after swimming to exhaustion. Our results show that hepatic glycogen has a crucial role to determine hyperglycemia during exercise. In contrast, hypoglycemia developed during exercise when glycogen was depleted. However, the ability of the liver to produce glucose from L-lactate, glycerol and L-glutamine was increased during exercise. Taken together, these findings suggest that the hepatic capacity to produce glucose from gluconeogenic substrates (except for L-alanine) was increased when hepatic glycogen stores were depleted. Thus, the increased capacity to produce glucose shown by livers from exercising rats must to be an important metabolic adaptation to protect against severe hypoglycemia.


Subject(s)
Blood Glucose/metabolism , Gluconeogenesis , Liver Glycogen/metabolism , Physical Conditioning, Animal , Animals , Liver/metabolism , Male , Rats , Rats, Wistar
15.
Zhongguo Yao Li Xue Bao ; 17(5): 455-9, 1996 Sep.
Article in English | MEDLINE | ID: mdl-9863174

ABSTRACT

AIM: To study the synergistic effect of G (glucagon, 0.02 mg.kg-1), H (hydrocortisone, 20 mg.kg-1) and E (phenylephrine + isoproterenol, both 1 mg.kg-1) during insulin-induced hypoglycemia (IIH) in rats with 6 h of food deprivation (F6 group). METHODS: I (insulin, 1 U.kg-1) was injected i.p. and 30 min later saline (F6 + I group), H, G and E individually or combined (G + H, G + E, H + E and G + H + E) were all injected i.p. and all experiments started 1 h after I injection. RESULTS: The rise in glycemia with H + G + E was greater than the sum of the responses to i.p. H, G and E individually or in double combination plus any single hormone. This effect was reproduced by G + H + Iso (isoproterenol, 1 mg.kg-1), G + H + Iso + Met (metoprolol, 1 mg.kg-1) and G + H + Sal (salbutamol, 1 mg.kg-1). A clear relationship was shown between glycemia and free fatty acids levels. Liver gluconeogenesis from glycerol (2 mmol.L-1) was higher in the group which received G + H + beta-adrenergic agonist vs control rats (F6 or F6 + I groups). CONCLUSION: (a) Acute hyperglycemia is obtained from a condition of IIH by combined i.p. of G + H + beta-adrenergic agonists; (b) This effect cannot be ascribed to a single hormone, but is a consequence of the combined effects of these substances; (c) Blood insulin levels and liver glycogen have no participation; (d) Lipolysis mediated by a beta-adrenergic mechanism and gluconeogenesis from glycerol contribute to the hyperglycemia.


Subject(s)
Blood Glucose/metabolism , Hyperglycemia/etiology , Hypoglycemia/metabolism , Animals , Drug Synergism , Fasting , Fatty Acids, Nonesterified/metabolism , Glucagon/pharmacology , Gluconeogenesis , Hydrocortisone/pharmacology , Hypoglycemia/chemically induced , Insulin , Isoproterenol/pharmacology , Lipolysis , Liver Glycogen/metabolism , Male , Phenylephrine/pharmacology , Rats , Rats, Wistar
16.
Braz J Med Biol Res ; 27(12): 2883-7, 1994 Dec.
Article in English | MEDLINE | ID: mdl-7550009

ABSTRACT

The synergistic effect of combined injection of glucagon (G), cortisol (C) and phenylephrine+isoproterenol (E) during hypoglycemia in male adult Wistar rats was investigated. For this purpose we injected insulin (1 mg/kg) and 30 min later saline (controls), C (20 mg/kg), G (0.02 mg/kg), or E (1 mg/kg), individually or combined (G+C, G+E, C+E and C+G+E). All drugs were injected i.p. and all rats were killed 60 min after insulin injection. The rise in glycemia with C+G+E was greater (delta = 107 mg/dl) than the sum of the responses to injection of C, G and E individually, or in double combination plus any single hormone injection. This synergistic effect was reproduced by G + C + isoproterenol (Iso) but not by G + C + phenylephrine (delta = 0 mg/dl). The results also showed a clear relationship between hyperglycemia and lipolysis. Thus, lipolysis mediated by a beta-adrenergic mechanism played a significant role in promoting hyperglycemia when Iso was combined with G and C.


Subject(s)
Hypoglycemia/drug therapy , Insulin , Lipolysis/drug effects , Animals , Drug Synergism , Drug Therapy, Combination , Gastrointestinal Agents/administration & dosage , Glucagon/administration & dosage , Hydrocortisone/administration & dosage , Hypoglycemia/chemically induced , Isoproterenol/administration & dosage , Male , Phenylephrine/administration & dosage , Rats , Rats, Wistar
17.
Braz. j. med. biol. res ; 27(12): 2883-7, Dec. 1994. graf
Article in English | LILACS | ID: lil-153288

ABSTRACT

The synergistic effect of combined injection of glucagon (G), cortisol (C) and phenylephrine + isoproterenol (E) during hypoglycemia in male adult Wistar rats was investigated. For this purpose we injected insulin (1 mg/kg), individually or combined (G+C, G+E, C+E and C+G+E). All drugs were injected ip and all rats were killed 60 min after insulin injection. The rise in glycemia with C+G+E was greater (delta = 107 mg/dl) than the sum of the responses to injection of C, G and E individually, or in double combination plus any single hormone injection. This synergistic effect was reproduced by G + C + isoproterenol (Iso) but not by G + C + phenylephrine (delta = 0 mg/dl). The results also showed a clear relationship between hyperglycemia and lipolysis. Thus, lipolysis mediated by a ß-adrenergic mechanism played a significant role in promoting hyperglycemia when Iso was combined with G and C


Subject(s)
Animals , Male , Rats , Glucagon/administration & dosage , Hydrocortisone/administration & dosage , Hypoglycemia/chemically induced , Insulin/adverse effects , Blood Glucose/analysis , Drug Therapy, Combination , Fatty Acids, Nonesterified/blood , Isoproterenol/administration & dosage , Lipolysis , Phenylephrine/administration & dosage , Rats, Wistar
18.
Trop Geogr Med ; 44(4): 317-21, 1992 Oct.
Article in English | MEDLINE | ID: mdl-1295140

ABSTRACT

Growth and sexual maturation was studied of 125 Brazilian patients with sickle cell disease whose ages ranged from 7 months to 42 years. Height and weight were significantly lower when compared with the unaffected population. The height and weight deficit increased in the age range of 11-19 years as compared with patients less than 11 years of age. Age of menarche, breast and pubic hair staging in girls, and genitalia staging and testicular volume measurements in boys indicated a delayed sexual maturation for both sexes. The comparison of adult and young patients, however, demonstrated that although puberty is delayed, a normal sexual maturation is attained later in life by most patients.


Subject(s)
Anemia, Sickle Cell/complications , Growth Disorders/epidemiology , Puberty, Delayed/epidemiology , Sexual Maturation , beta-Thalassemia/complications , Adolescent , Adult , Age Factors , Anemia, Sickle Cell/genetics , Body Height , Body Weight , Brazil/epidemiology , Child , Child, Preschool , Female , Growth Disorders/diagnosis , Growth Disorders/etiology , Heterozygote , Homozygote , Humans , Infant , Male , Outpatient Clinics, Hospital , Puberty, Delayed/diagnosis , Puberty, Delayed/etiology , beta-Thalassemia/genetics
SELECTION OF CITATIONS
SEARCH DETAIL
...