Glutamine has been shown to be an important metabolic substrate of enterocytes in many animals, including cats, dogs, hamsters, human beings, monkeys, rabbits, rats, and sheep. To determine whether glutamine is important in the metabolism of cells of the equine gastrointestinal tract, we examined transintestinal differences in glutamine concentrations in the arterial and venous circulation, and measured activity of the major glutamine catabolizing enzyme, glutaminase. Arteriovenous differences provide an index of the amount of a given substrate removed by the tissue across which the measurements are made, and commonly are expressed as a percentage of substrate removed, or percent extraction. Arteriovenous differences for glutamine were determined in 7 anesthetized adult horses (weight, 450 to 500 kg) before and after an IV glutamine infusion. The mean baseline arterial glutamine concentration (+/- SEM) was 572 +/- 24 microM; this concentration quadrupled (to 2,167 +/- 135 microM, P < 0.01) 1 minute after IV bolus infusion of a 17.5-g glutamine load. Baseline extraction by the portal-drained viscera was 7.5 +/- 1.5%; this value increased to 18 +/- 2% at 1 minute (P < 0.01) and had returned to baseline values 60 minutes later. Arteriovenous differences were greatest across the jejunum (11.8 +/- 1.8% in the baseline period vs 33.1 +/- 3.1% at 1 minute, P < 0.001), with smaller differences across the colon, suggesting that the jejunum was the more avid utilizer of glutamine. Glutaminase activity was 4.38 +/- 0.16 and 4.00 +/- 0.60 micromol/mg of protein/h under standard conditions in jejunal and ileal mucosa, respectively. Kinetic studies of jejunal glutaminase revealed the enzyme to have a Km of 3.81 +/- 0.35 mM and a Vmax of 8.08 +/- 0.54 micromol/mg of protein/h, suggesting that the small intestine of horses has a high capacity to extract and metabolize circulating glutamine.

Although mammals produce either sperm or eggs depending on their sex, newborn MRL/MpJ male mice contain oocytes within their testes. In our previous study, the testicular oocyte appears as early as day 0 afterbirth and has morphological characteristics as an oocyte such as zona pellucida and follicular epithelial cells. Based on the observation of F1 between MRL/MpJ and C57BL/6, one of the genes causing the appearance of testicular oocyte exists on the Y chromosome. In the present study, we found testicular oocytes within newborn AKR mice. We have also analyzed the Sry genes from several inbred mouse strains and identified a shortened glutamine repeat near the C-terminal region that is unique to MRL and AKR. These results suggest that polymorphism of glutamine repeat within SRY correlates with the appearance of testicular oocyte and this phenotype is derived from AKR, one of the original strains of MRL mice.

Foi avaliado o efeito da adição de glutamina, ácidos graxos poliinsaturados ou parede celular de levedura à dieta de leitões desmamados sobre a atividade das enzimas pancreáticas (lipase, amilase e tripsina) e da mucosa intestinal (dipeptidase, sacarase e maltase) e sobre o desempenho. Foram utilizados 45 leitões desmamados e distribuídos em delineamento em blocos casualizados, em esquema fatorial, com quatro dietas (T1 - dieta basal (DB); T2 - DB + 1% de glutamina; T3 - DB + 0,2% de parede celular de levedura; T4 - DB + 5% de óleo de peixe) e duas idades de abate (sete e 14 dias pós-desmame). O desempenho foi medido nas duas primeiras semanas pós-desmame. A adição de 1% de glutamina na dieta dos leitões aumentou a atividade específica e total da amilase, e atividade total da tripsina na segunda semana pós-desmame. Os demais aditivos não alteraram a atividade das enzimas digestivas nos leitões. Também foi observado aumento na atividade total da lipase, e atividade específica da tripsina e maltase em função da idade pós desmame. De modo geral, as atividades das enzimas digestivas estiveram correlacionadas positivamente, com exceção da dipeptidase que não se correlacionou com nenhuma outra enzima. Foi observada correlação positiva entre ganho de peso e atividades da lipase e da amilase. Os aditivos incluídos na dieta não influenciam o desempenho dos leitões no pós-desmame. | It was evaluated the effect of the addition of glutamine, polyunsaturated fatty acids or cellular wall of yeast to the diet of weaned pigs on the activity of the pancreatic enzymes (lipase, amylase and trypsin) and the intestinal mucous membrane (dipeptidase, sucrase and maltase) and on the performance. Forty-five weaned pigs were used and distributed in a randomized block design, in factorial outline, with four diets (T1 - basal diet (BD); T2 - BR + 1% glutamine; T3 - BD + 0,2% cellular wall of yeast; T4 - BD + 5% fish oil) and two slaughter ages (seven and 14 days post weaning). The performance was measured in the first two weeks post-weaning. The addition of 1% glutamine in the diet of pigs increased the specific and total activity of the amylase, and total activity of the trypsin in the second week post weaning. The others supplements not change the activity of the digestive enzymes in the pigs. Also an increase was observed in the total activity of the lipase, and specific activity of the trypsin and maltase in function of the age post-weaning. In general, the activities of the digestive enzymes were correlated positively, except for the dipeptidase that was not correlated with any other enzyme. Positive correlation was observed between weight gain and activity of the lipase and of the amylase. The supplements included in the diet not influence the performance of weaned pigs.