Angiotensin-(1-7) antagonist [D-Ala7-Ang-(1-7);A-779] attenuates post-suspension hypotension in Sprague-Dawley rats.

Abstract

Cardiovascular deconditioning manifested by reduction in mean arterial pressure (MAP) and cardioaccleration are usually observed in astronauts during standing postflight. The head-down tilt (HDT) rat model with "unloaded" hindlimbs has been extensively studied because some of the observed responses mimic observations made during exposure to microgravity. Angiotensin-(1-7) is a biologically active component of the renin-angiotensin system that acts to oppose the pressor and proliferative actions of Angiotensin II. It produces a hypotensive response by either stimulating production of vasodilator prostaglandins (i.e., prostacyclin), increasing nitric oxide or both. In the present study, we have evaluated the role of a specific inhibitor of Ang-(1-7), D-Ala7-Ang-(1-7)[A-779], as a countermeasure against post-suspension hypotension.

• Authors: M A Bayorh, M Wang, R R Socci, D Eatman, N Emmett, M Thierry-Palmer
• Journal: Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology (J Gravit Physiol) Vol. 6 Issue 1 Pg. P115-6 (Jul 1999) ISSN: 1077-9248 [Print] United States
• PMID: 11542983 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• 7-Ala-angiotensin (1-7)
• Peptide Fragments
• Angiotensin II

Topics

• Angiotensin II (analogs & derivatives, pharmacology)
• Animals
• Blood Pressure (drug effects)
• Heart Rate
• Hindlimb Suspension
• Hypotension, Orthostatic (prevention & control)
• Male
• Peptide Fragments (pharmacology)
• Rats
• Rats, Sprague-Dawley
• Weightlessness Countermeasures
• Weightlessness Simulation