High altitude exposure on body weight in male rats: Effect of cyproheptadine

Abstract

The role of 5-hydroxytryptamine (5-HT), as mediator of body  weight changes during  high altitude exposure  was investigated in male rats using cyproheptadine, a 5-HT antagonist. At sea level male rats daily  injected  with  either 10 mg/kg  of cyproheptadine chlorhydrate or saline solution showed no differences in body weight after five days of treatment. Other rats were acutely exposed to an altitude of 4,338.m. and they were daily injected with either cyproheptadine or the vehicle. Rat weight was recorded daily during four days. Through the first and second days of exposure, a similar reduction in body weight was observed in both groups. After three days of exposure at high altitude, cyproheptadine-treated group decreases body weight to a lesser extent than the control  group.  Between  the  third  and  fourth  days  of permanence at high altitude a gain of weight only occurred in the cyproheptadine treated group. Since cyproheptadine and  saline treated groups at sea level showed  the same pattern of weight curves whereas hypoxic male animals cyproheptadine-treated  group  had  a  better  weight  than those obtained in saline treated group, it is suggested that 5-HT may be mediating body weight reduction during high altitude exposure of male rats.