OBJECTIVETo study the effects of different administrations of antibodies against adipocyte plasma membrane proteins on growth and fat deposition in rats.

METHODNinety six female SD rats that weighed approximately 140 g were allotted randomly into four groups which were given negitive control yolk and positive yolk containing antibody (IgY) against adipocyte plasma membrane (APM) proteins by intragastric administration (i.g.) and subcutaneous injection (s.c.) respectively. Rats were given 1 ml of yolk for every three days in i.g. groups. Rats were given 1 ml of yolk for 4 consecutive days, and the procedure was repeated after one month. The trial lasted for 75 days after which rats were slaughtered for carcass analysis and sampling.

RESULTSThe body weight gain and food intake of rats were not different between treatment and control groups. In i.g. goups, positive yolk decreased mesemteric fat index, paramertrial fat index and perirenal fat index (P < 0.05), reduced serum triglycerides (P < 0.05) and increased serum free fatty acids (FFA) (P < 0.01), and also decreased serum leptin, insulin and TNF-alpha levels ( P < 0.01 or P < 0.05), but did not affect gastrocnemius muscle index and serum cholesterol. In s.c. groups, positive yolk increased gastrocnemius muscle index (P < 0.05), reduced serum triglycerides and serum leptin (P < 0.01), increased serum TNF-alpha (P < 0.05), but did not affect adipose tissue depots, serum FFA, cholesterol and insulin.

CONCLUSIONAdministration of yolk antibody against APM proteins could effectively improve body composition of rats, and the treatment by intragastric administration could give better effect than by subcutaneous injection.