Renin secretion in Lyon hypertensive rats

In genetically hypertensive rats of Lyon strain (LH), both development and maintenance of hypertension are extremely sensitive to the chronic blockade of the renin-angiotensin system. However, LH rats exhibit a low renin secretory profile as indicated by (1) low basal plasma renin concentration; (2) blunted renin responses to reductions of renal perfusion pressure and beta-adrenoceptor stimulation both in vitro (isolated perfused kidney) and in vivo (conscious rat). None of the latter abnormalities are corrected by chronic sodium deprivation or when hypertension is prevented by hydralazine or perindopril treatment. Future studies will therefore have to elucidate the 'renin paradox' in LH rats.