Faculty Collaboration Database

Importance of the renin-angiotensin system in the regulation of arterial blood pressure in conscious mice and rats. Acta Physiol Scand 2005 Mar;183(3):309-20

Date

03/04/2005

Pubmed ID

15743391

DOI

10.1111/j.1365-201X.2004.01401.x

Scopus ID

2-s2.0-15244344204 (requires institutional sign-in at Scopus site)   24 Citations

Abstract

AIM: The present experiments were designed to determine the mechanism(s) for increased sensitivity to blockade of the renin-angiotensin system in mice in comparison with rats.

METHODS: Mice and rats, with indwelling femoral arterial and venous catheters, were chronically administered angiotensin II or pharmacological inhibitors of the renin-angiotensin system as sodium intake was altered.

RESULTS: Increasing sodium intake led to suppression of circulating renin, angiotensin II, and aldosterone in rats and mice in the absence of alterations in arterial blood pressure. Additional experiments demonstrated that continuous intravenous infusion of angiotensin II (20 ng kg(-1) min(-1)) significantly increased arterial blood pressure by approximately 35 mmHg in conscious rats at all levels of sodium intake (n = 6). In contrast, arterial pressure was unaffected by angiotensin II infusion in conscious mice under conditions of low sodium intake, although arterial pressure was increased by 16 mmHg when mice were administered a high sodium intake while infused with angiotensin II (n = 6). In comparison, blockade of the endogenous renin-angiotensin system led to significantly greater effects on arterial pressure in mice than rats. Continuous infusion of captopril (30 microg kg(-1) min(-1)) or losartan (100 microg kg(-1) min(-1)) resulted in a 55-90% greater fall in blood pressure in conscious mice in comparison with conscious rats.

CONCLUSION: The present studies indicate that arterial pressure in mice is more dependent upon the endogenous renin-angiotensin system than it is in rats, but mice are more resistant to the hypertensive effects of exogenous angiotensin II.

Author List

Cholewa BC, Meister CJ, Mattson DL

MESH terms used to index this publication - Major topics in bold

Angiotensin II
Animals
Aorta, Thoracic
Blood Pressure
Dose-Response Relationship, Drug
Male
Mice
Mice, Inbred C57BL
Rats
Rats, Sprague-Dawley
Renin-Angiotensin System
Sodium, Dietary
Species Specificity
Tissue Culture Techniques
Vasoconstriction