STEREOLOGICAL STUDY OF THE TROPHIC EFFECTS OF THE RENIN-ANGIOTENSIN SYSTEM ON THE RAT ADRENAL ZONA GLOMERULOSA

  • 1 January 1979
    • journal article
    • research article
    • Vol. 129  (OCT) , 561-570
Abstract
Left renal artery stenosis increases and timolol maleate chronic administration decreases systolic blood pressure, plasma renin activity, and plasma aldosterone concentration in adult male rats. In hypertensive animals the volume of the zona glomerulosa, the volume and number of zona glomerulosa cells, and the volume of the mitochondrial compartment and the surface area of smooth endoplasmic reticulum membranes and mitochondrial cristate are significantly increased. The volume of the lipid compartment is reduced, and several clumps of electron-dense granules appear at the juxta-sinusoidal pole of the cells. Opposite results are found in the zona glomerulosa of hypotensive rats, with the exception that the volume of the lipid compartment shows no significant change. The renin-angiotensin system may be involved in the maintenance and stimulation of growth in the zona glomerulosa. Since in the hypertensive rats the increase in the volume density of electron-dense granules fits well with that in the intracellular concentration of aldosterone, the working hypothesis is that these granules are aldosterone-containing secretory organelles.