EFFECTS OF HYPERPROLACTINEMIA ON PLASMA-GLUCOSE AND PROLACTIN IN RATSEXPOSED TO ETHER STRESS

The present study was designed to characterize the effect of chronic h yperprolactinemia on plasma glucose and prolactin (PRL) during ether s tress in male and female rats. Wistar rats of both sexes were divided into a hyperprolactinemic group (bearing pituitary grafts) and a contr ol group (sham operated). They were exposed to ether during 10 min and had blood samples taken immediately before, and 5, 15, 40, and 70 min after ether exposure and assayed for glucose and PRL concentrations. Ether stress induced significant increase in plasma PRL of control rat s at 5 min (male 171%, female 161%; P < 0.01), but only a mild PRL inc rease occurred in grafted rats (male 66%, female 62%; P < 0.05). Contr ol male rats sustained elevated plasma PRL longer than females. There was a marked elevation of glucose levels at 5 min (P < 0.01) which pea ked at 15 min in all groups. Grafted rats had glucose levels significa ntly above control at baseline (female 15%, P < 0.05) and at 40 min (m ale 25%, female 29%; P < 0.05). It is concluded that ether-induced PRL release produced a rapid and transient response, more intense in male s than in females and which was impaired by previous hyperprolactinemi a (pituitary grafts). There was an acute hyperglycemic response, plasm a glucose being increased in grafted rats, supporting the hypothesis o f a hyperglycemic effect of PRL.