OBJECTIVETo establish a rat model of hypophyseal compression and observe and analyze the changes in its biological characteristics after operation.

METHODSThe rats were subjected to compression of the pituitary gland by stuffing the autologous muscular tissue into the hypophyseal fossa. The postoperative mortality of the rats was recorded and the volume of the hypophyeseal fossa, body weight, daily food intake, water intake, urine volume and urine specific gravity were measured.

RESULTSRat models of the hypophyseal compression model were successfully established by this procedure, which resulted in an increase of the volume of hypophyseal fossa by 35%. Rapid body weight loss occurred within 5 weeks after the operation (by as much as 31% on day 10). The rats exhibited recovery of appetite after 2 weeks, but their food intake was still less than that in the control group. Manifestations of central diabetes insipidus occurred gradually, which were especially obvious at 2 weeks and persisted afterwards, and at this time point, significant increment of urine volume (55.4-/+15.9 vs 18.5-/+5.8 ml) and lowered urine gravity (1.011-/+0.004 vs 1.036-/+0.006) were observed.

CONCLUSIONRat models of hypophyseal compression can be established successfully by the described procedure, and the compression results in alteration of the rats' metabolic behaviors, which may differ from the effects of hypophysectomy and damage of pituitary stalk.