Inhibition of Angiotensin - Converting Enzyme in CBA Mice with Psychosocial Hypertension

Abstract

Captopril (SQ 14,225) was acutely administered to control mice and to mice which had developed hypertension as a result of being caged in a manner which facilitates social interactions and competition. Systolic blood pressure was measured four hours after captopril administration, and blood was taken for measurement of plasma renin activity (PRA) several days later. Captopril produced no effect on normotensive control mice living in isolation nor did it reduce the blood pressure of the hypertensive mice on days 1, 7, and 14 following their placement in the special caging, despite the fact that their PRA was significantly elevated at these times. In contrast, by 1.5 months after placement in the cages and continuing for the next 5.5 months, captopril abolished the hypertension; PRA was normal during this period. We conclude that the increased PRA existing during the early stage of this psychosocial model of hypertension is not a significant direct contributor to the hypertension, whereas the renin-angiotensin system may be essential for the maintenance of the hypertension beyond the early stage.

Key Words:

• Angiotensin Converting Enzyme
• Captopril
• CBA Mice
• Stree Psychosocial Hypertension