Sex-differentiated enzyme levels and oestrogen uptake in adult rats treated neonatally with tamoxifen or CI-628

Neonatal diethylstilbestrol alters blood pressure and CNS drinking response in SHR and WKY rats

Neonatal SHR and WKY rats were treated with diethylstilbestrol or propylene glycol (controls). Control SHR had higher blood pressures than WKY rats. Neonatal diethylstilbestrol treatment delayed the onset and full expression of hypertension in the male SHR but had no effect on blood pressure in the other animals. Neonatal diethylstilbestrol treatment had an adverse effect on body weights of male SHR and WKY rats through 98 days of age (not statistically decreased thereafter). Adult female SHR and WKY rats treated neonatally with diethylstilbestrol had body weights significantly greater than the control females. Neonatal treatment with diethylstilbestrol resulted in precocious puberty in female SHR and WKY rats. Control female SHR and WKY rats and female SHR treated neonatally with diethylstilbestrol had attenuated angiotensin - II induced drinking response from the central administration of estrogen in adulthood. The angiotensin II - induced drinking response was not significantly attenuated by central estrogen in adult WKY females exposed neonatally to diethylstilbestrol. Neonatal diethylstilbestrol treatment of WKY female rats appears to have altered neuroendocrine secretions that control CNS drinking behavior.

Altered activation/detoxication enzymology following neonatal diethylstilbestrol treatment

The effects of neonatal exposure to diethylstilbestrol (DES) on hepatic activation/detoxication enzyme levels in the adult rat were investigated. Neonatal exposure of male rats to DES (DES males) decreased the endogenous levels of UDP-glucuronyltransferase as compared to control males. Female rats exposed neonatally to DES (DES females) had higher endogenous epoxide hydrolase and glutathione transferase activity levels than control females. Adult animals treated neonatally with DES also had altered metabolic potential following exposure to 3-methylcholanthrene and phenobarbital. The DES males treated in adulthood with 3-methylcholanthrene had higher benzo(a)pyrene hydroxylase activities and lower UDP-glucuronyl-transferase activity levels than did control males treated in adulthood with 3-methylcholanthrene. The DES males exposed in adulthood to phenobarbital had reduced cytochrome P-450 and glutathione transferase activity levels as compared with respective controls. The DES females treated in adulthood with 3-methylcholanthrene had lower benzo(a)pyrene hydroxylase and epoxide hydrolase activity levels than control females receiving 3-methylcholanthrene. The DES females challenged in adulthood with phenobarbital also had decreased benzo(a)pyrene hydroxylase, epoxide hydrolase, UDP-glucuronyltrasferase, and glutathione transferase activity levels as compared with respective controls. Our results demonstrated that neonatal exposure to DES changed the endogenous levels of specific hepatic enzymes and altered the metabolic response of these adult animals to a carcinogen and a drug.