Related Experiment Videos
Renin distribution in the rabbit renal microvasculature
L A Juncos1, S Ito, R Nobiling
1Department of Medicine, Henry Ford Hospital, Detroit, Mich. 48202.
Hypertension (Dallas, Tex. : 1979)
|February 1, 1992
Summary
Chronic renin-angiotensin system stimulation increases renin in the distal afferent arteriole, not the glomerulus. This finding impacts understanding of renal microvascular renin distribution under altered sodium intake or enalapril treatment.
Area of Science:
- Nephrology
- Renal Physiology
- Endocrinology
Background:
- Renin is typically localized to the juxtaglomerular afferent arteriole.
- Chronic renin-angiotensin system (RAS) stimulation may alter renin distribution within the renal vasculature.
Purpose of the Study:
- To investigate renin distribution along the renal microvasculature under conditions of chronic RAS stimulation.
- To quantify renin content in specific segments of the afferent arteriole and glomerulus.
Main Methods:
- Quantitative analysis and immunocytochemistry were employed in rabbits.
- Renin content was measured in microdissected segments: proximal afferent arteriole (p-AF), distal afferent arteriole (d-AF), and glomerulus (GL).
- Experimental groups included normal sodium diet, low sodium diet, and enalapril treatment.
Main Results:
- Control rabbits showed minimal renin in p-AF (0.3 ng AI/hr/arteriole) and moderate levels in d-AF (27.0 ng AI/hr/arteriole) and GL (2.8 ng AI/hr/GL).
- Low sodium diet and enalapril significantly increased renin in the d-AF (53.1 and 68.4 ng AI/hr/arteriole, respectively).
- Renin levels in the GL remained unchanged, and increases in p-AF were minimal compared to d-AF.
Conclusions:
- Chronic RAS activation primarily enhances renin accumulation in the distal afferent arteriole.
- Renin distribution shifts upstream towards the interlobular artery under stimulated conditions.
- The glomerulus does not appear to be a significant site for renin accumulation during RAS stimulation.