Increased growth and protein deposition in rats treated with antibodies to adipocytes

Young growing rats treated with an antiserum to adipocytes showed marked reductions in several adipose tissue depots but surprisingly demonstrated increased body weight gain. During the first 3 wk after treatment body weight gain increased by 17% with no effect on food intake, whereas during weeks 3-7 body weight gain increased by 40-50% and was accompanied by a 15% increase in food intake. These animals thus exhibited increased food conversion efficiencies (intake/gain) of approximately 15-20% for almost 2 mo. Subsequently, food intake and body weight gain returned to normal (although body weight remained elevated) up to 6 mo. By this time several fat depots were still reduced in size, although total (chemical) fat was identical in treated and control groups. These results suggest that 1) reduction of body fat depots can be achieved using antibodies to adipocytes, 2) compensatory increases in lean body mass can occur, and 3) total fat mass may be regulated.