Nitric Oxide and Salt Resistance in Dahl Rats: No Role of Inducible NO Synthase

0573073 - FGÚ 2024 RIV CZ eng J - Journal Article
Zicha, Josef - Řezáčová, Lenka - Vaněčková, Ivana
Nitric Oxide and Salt Resistance in Dahl Rats: No Role of Inducible NO Synthase.
Physiological Research. Roč. 72, č. 1 (2023), s. 123-127. ISSN 0862-8408. E-ISSN 1802-9973
R&D Projects: GA MŠMT(CZ) LX22NPO5104; GA ČR(CZ) GC19-08260J
Institutional support: RVO:67985823
Keywords : high salt intake * Dahl salt-resistant rats * blood pressure * NO synthase II * aminoguanidine * AMT * renin-angiotensin system * sympathetic nervous system * nitric oxide
OECD category: Cardiac and Cardiovascular systems
Impact factor: 2.1, year: 2022
Method of publishing: Open access
https://www.biomed.cas.cz/physiolres/pdf/2023/72_123.pdf

Inducible NO synthase (NOS II) was proposed to play an important role in salt resistance of Dahl salt-resistant (SR/Jr) rats. Its chronic inhibition by specific inhibitors was accompanied by blood pressure (BP) elevation in animals subjected to high salt intake. The aim of our study was to evaluate 1) whether such inhibitors affect BP and/or its particular components (sympathetic tone and NO-dependent vasodilation) only under the conditions of high salt intake, and 2) whether similar BP effects are elicited after systemic or intracerebroventricular (icv) application of these inhibitors. Wistar rats fed Altromin diet (0.45 % NaCl) and SR/Jr rats fed either a low-salt (LS, 0.3 % NaCl) or a high-salt (HS, 4 % NaCl) diet were studied. Aminoguanidine (AMG) and 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (AMT) were used as NOS II inhibitors. BP and its responses to acute blockade of renin-angiotensin system (captopril), sympathetic nervous system (pentolinium) and NO synthase (L-NAME) were measured in conscious cannulated rats. There were no significant changes of BP or its components in either Wistar rats or SR/Jr rats subjected to chronic inhibition of NOS II by peroral aminoguanidine administration (50 mg/kg/day for 4 weeks). This was true for SR/Jr rats fed either LS or HS diets. Furthermore, we have studied BP effects of chronic icv administration of both NOS II inhibitors in SR/Jr rats fed HS diet, but we failed to find any BP changes elicited by such treatment. In conclusion, inducible NO synthase does not participate in the resistance of SR/Jr rats to hypertensive effects of excess salt intake.
Permanent Link: https://hdl.handle.net/11104/0343581