1. Contribution of Central Nitric Oxide to the Regulation of Blood Pressure and Sodium Balance in DOCA-salt Hypertension
- Author
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Shin-ichiro Ozeki, Shinji Seto, Masazumi Akahoshi, Shoichi Nagao, Hirokuni Tetsuo, and Katsusuke Yano
- Subjects
Male ,medicine.medical_specialty ,Ganglionic Blockers ,medicine.medical_treatment ,Sodium ,Drinking ,Ganglionic blocker ,chemistry.chemical_element ,Blood Pressure ,Sodium Chloride ,Nitric Oxide ,Hexamethonium ,Nitric oxide ,Eating ,Norepinephrine ,chemistry.chemical_compound ,Internal medicine ,Renin ,Renin–angiotensin system ,medicine ,Animals ,Enzyme Inhibitors ,Rats, Wistar ,Desoxycorticosterone ,Saline ,Pharmacology ,omega-N-Methylarginine ,biology ,Rats ,Arginine Vasopressin ,Nitric oxide synthase ,Endocrinology ,Blood pressure ,chemistry ,Hypertension ,biology.protein ,Omega-N-Methylarginine ,Nitric Oxide Synthase ,Cardiology and Cardiovascular Medicine ,hormones, hormone substitutes, and hormone antagonists - Abstract
We examined whether central nitric oxide is involved in blood pressure (BP) regulation in deoxycorticosterone acetate (DOCA)-salt hypertension. DOCA-salt rats were intracerebroventricularly infused (ICV) NG-monomethyl L-arginine (L-NMMA) for 4 weeks at either low (0.08 mg/kg/d; n = 8) or high (0.16 mg/kg/d; n = 8) dose. Saline ICV (n = 9) and intraperitoneal infused L-NMMA (low, n = 6; high dose, n = 6) were served as controls. Also, L-NMMA ICV (low, n = 6; high dose, n = 6) was conducted in normal rats. At week 3 and after, DOCA-salt with low L-NMMA ICV showed a higher BP than saline ICV (at week 4: 167.4 +/- 3.6 vs. 150.3 +/- 3.9 mm Hg, P < 0.01); this difference of BP was cancelled after ganglionic block. High L-NMMA ICV did not affect the trend of BP; however, it caused a reduced amount of saline drinking and a less estimated sodium retention than saline or low L-NMMA ICV (for 3 wk; 47.5 +/- 1.1 vs. 66.0 +/- 3.7 and 61.7 +/- 2.5 mmol, P < 0.01). In normal rats, high, but not low, L-NMMA ICV elevated BP with no effect on drinking behavior. Intraperitoneal infused L-NMMA did not affect the development of hypertension and/or sodium balance. These data suggested that, in DOCA-salt, central nitric oxide is involved in BP regulation through the dual action on sympathetic nervous activity and sodium balance.
- Published
- 2006