Endocrine Abstracts

The goal of this study was to determine whether injections of bombesin increase the plasma concentration of thyroxine (T4) , triiodothyronine (T3), growth hormone (GH), milk amount and constituents in the cows. sixty cows were randomly divide into 4 groups. Each group received daily injections of either saline or 1, 2, 4 milligrams bombesinper kilogram for 15 days. Blood samples were collected daily on day 3 before injections untill 3 days after the last injection . Samples were assayed for plasma T3, T4 and GH concentrations of the cows by double-antibody RIA. Milk samples were daily collected from day 1 day till day 21 of experiment. Milk samples were assayed for protein, fat and lactose constituents. The daily amount of milk and BW changes were determined throughout the experiment. Injections of saline, 1 and 2 and 4 milligrams bombesin per kilogram did not changed the plasma concentration of the GH during the period of injections in the all animals. Injections of saline, 1 and 2 milligrams bombesin per kilogram did not changed the plasma concentration of the T3 and T4 during the period of injections in the all animals. Injection of 4 milligrams bombesinper significantly increased the plasma concentration of the T3 and T4 during injections in the animals. Injections of 4 milligram bombesin significantly increased the amount of milk by 25%. The protein, fat and lactose constituents of milk were not changed among all animals in the different groups. The result of these experiment indicated that long injection of bombesin may increase the plamsa concentration of T3 and T4 and the amount of milk in the cow.

Key word : bombesin, T3, T4, GH, cow