Plasma renin activity determined by two different methods in spontaneously hypertensive rats

Area of Science:

• Physiology
• Cardiovascular Research
• Renal Physiology

Background:

• Discrepancies in previous laboratory reports on plasma renin activity (PRA) in spontaneously hypertensive rats (SHR) necessitated further investigation.
• Existing literature suggested a potential suppression of PRA in SHR linked to elevated blood pressure, requiring validation.

Purpose of the Study:

• To resolve conflicting findings regarding PRA levels in SHR.
• To accurately determine PRA in 15-week-old SHR using two distinct methodologies.
• To establish appropriate normotensive control groups for comparison.

Main Methods:

• Plasma renin activity (PRA) was measured in 15-week-old spontaneously hypertensive rats (SHR).
• Two established methods, Boucher et al. and Haber et al., were employed for PRA determination.
• Normotensive Donryu (DON) and Wistar-Kyoto (WKY) rats served as control groups.

Main Results:

• Using Boucher's method, SHR exhibited significantly lower PRA than DON rats, but not WKY rats.
• Using Haber's method, SHR showed no significant difference in PRA compared to either DON or WKY rats.
• DON rats displayed significantly higher PRA than WKY rats, irrespective of the method used.

Conclusions:

• The study confirms that 15-week-old SHR have plasma renin activity (PRA) within the normal range.
• Previous conclusions suggesting PRA suppression in SHR due to hypertension require revision.
• The use of appropriate control strains, like WKY, is crucial for accurate interpretation of SHR physiological data.