Differential regulation of circulating and renal ACE2 and ACE in hypertensive mRen2.Lewis rats with early-onset diabetes.

We examined the impact of early diabetes on the circulating and kidney renin-angiotensin system (RAS) in male and female mRen2.Lewis (mRen2) hypertensive rats. Diabetes (DB) was induced by streptozotocin (STZ; 65 mg/kg) at 11 wk of age for 4 wk without insulin replacement.

Long-term systemic angiotensin II type 1 receptor blockade regulates mRNA expression of dorsomedial medulla renin-angiotensin system components.

In Fischer 344 (F344) rats, renin-angiotensin system (RAS) blockade for 1 yr with the angiotensin II type 1 (AT(1)) receptor blocker L-158,809 prevents age-related impairments in metabolic function, similar to transgenic rats with low glial angiotensinogen (Aogen). Brain RAS regulation may contribute to the benefits of long-term systemic AT(1) antagonism. We assessed the mRNA of RAS components in the dorsomedial medulla of F344 rats at 3 (young; n = 8) or 15 mo of age (old; n = 7) and in rats treated from 3 to 15 mo of age with 20 mg/l of the AT(1) receptor antagonist L-158,809 (Old+L; n = 6).

Autonomic control of the heart is altered in Sprague-Dawley rats with spontaneous hydronephrosis.

The renal medulla plays an important role in cardiovascular regulation, through interactions with the autonomic nervous system. Hydronephrosis is characterized by substantial loss of renal medullary tissue. However, whether alterations in autonomic control of the heart are observed in this condition is unknown.

Long-term AT1 receptor blockade improves metabolic function and provides renoprotection in Fischer-344 rats.

Fischer-344 (F344) rats exhibit proteinuria and insulin resistance in the absence of hypertension as they age. We determined the effects of long-term (1 yr) treatment with the angiotensin (ANG) II type 1 (AT(1)) receptor blocker L-158,809 on plasma and urinary ANG peptide levels, systolic blood pressure (SBP), and indexes of glucose metabolism in 15-mo-old male F344 rats. Young rats at 3 mo of age (n = 8) were compared with two separate groups of older rats: one control group (n = 7) and one group treated with L-158,809 (n = 6) orally (20 mg/l) for 1 yr.