Long-time observation of blood glucose and pathological phenotype of leptin knockout obese rats / 中国比较医学杂志

ABSTRACT

Objective To obtain more physiological data of Leptin knockout SD rats available for the user , the long-term observation of fasting blood glucose and pathological phenotypes were performed .Methods The protein expression levels in liver tissues were determined by western blot .Body weight of Leptin knockout rats ( Leptin-/-) and littermate lean rats (Leptin+/+) were weighed up at 1,3,6,8 months of age.Fasting blood glucose of Leptin +/+rats and Leptin-/-rats at 1,3,6,8 months of age were measured using One Touch? brand blood glucose monitoring systems.Pathological changes of pancreas and livers of Leptin -/-rats were observed by the method of HE staining and Immunohistochemistry (IHC).Results Short null Lepin proteins were expressed in liver tissues from Leptin -/-rats. Leptin-/-rats become heavier than Leptin +/+rats since they were one month old .The body weight of Leptin -/-rats at 8 months of age was twice as heavy as Leptin +/+rats, female Leptin-/-rats weighing 884g, and male Leptin-/-rats weighing 1200g.Overt hyperglycemia was observed during the first month after birth .Compared with Leptin+/+female rats,the fasting blood glucose of Leptin -/-female rats was increased by 40%-26%from 1 to 6 months old. After that, blood glucose values decreased and eventually become nearly normal at 8 months of age.Pathological examination indicated that Leptin -/-rats at 8 months of age had a fatty liver , more pancreas islets with lager volume and more beta cells with increased insulin secretion .Conclusion Leptin-/-rat were characterized by obesity , fatty liver, islet cell hyperplasia and early hyperglycemia .