Adrenocortical activity in fetal SHR and WKY rats

There is increasing evidence that the intrauterine milieu and corticosteroi d exposure play a role in the etiology of hypertension. We examined adrenoc ortical gene expression and circulating corticosteroids in the d 21 fetal s pontaneously hypertensive rat (SHR) and its normotensive genetic control, t he Wistar-Kyoto (WKY) rat. By RNase protection assays, we found no differen ces in the relative abundances of mRNAs for P450scc and P450c11 beta, and b arely detectable P450c11AS mRNA in the adrenals of fetal SHR and WKY rats. P450c11B3 RNA was undetectable by reverse transcription polymerase chain re action in both SHR and WKY fetuses. The zonal expression of P450c11 mRNA wa s comparable in SHR and WKY fetuses by in situ hybridization histochemistry . There were no significant differences in peripheral levels of aldosterone and corticosterone by radioimmunoassay in fetal SHR and WKY rats. Based up on the absence of distinct differences in the aspects of adrenocortical act ivity examined, it is unlikely that they are integral in the programming of hypertension in this model.