The Effect Of Exogenous Leptin On The Growth And Development Of The Digestive System In Neonatal Aletai Lamb

In present paper the effect of exogenous leptin on the growth and development of the digestive system was studied in the neonatal lamb. The experimental animals were randomly divided into three groups; the ewe rearing group, artificial milk supplement group and artificial milk plus leptin group, respectively. The fallowing items were tested: 1) the blood physiological and biochemical indices, 2) the concentration of plasma leptin, 3) the coefficient of digestive organs, 4) the morphometry of small intestine and 5) digestive enzymes both in pancreas and in brush border. .The results were that exogenous leptin supplement increased the content of plasm glucose, but extremely decreased the content of plasm cholesterol, compared with that in the ewe rearing group, and the content of triglyceride compared with that in the ewe rearing and artificial milk supplement group. The relative weight of pancreas in the leptin supplement group was higher than that in other two groups. The length of small intestine in leptin feeding lambs was significantly longer than that in the other two groups, mainly ascribing to the longer duodenum and jejunum in leptin feeding group. Regarding the length of villi it was longest in the ewe rearing lambs but the crypts were deeper in leptin feeding group than in ewe rearing group. In addition the activity of sucrase in the proximal and intermediate small intestine of leptin feeding group showed the tendency of approaching to the ewe rearing group. However, the activity of mucosal amylase in the intermediate and distal jejunum was higher in leptin feeding lambs than in both ewe rearing and artificial milk supplement groups. These results indicated that the exogenous leptin may have promoting effect on the growth and development of digestive system in Altai lambs, mainly via stimulating the growth and development of digestive organ and digestive enzymes.