The effect of a sulphated mucopolysaccharide (RO1-8307) on adrenal and kidney morphology and function in the rat.

Abstract

RO1–8307, a heparinoid with low anticoagulant activity, was injected into male rats on a controlled diet. The width of the zona glomerulosa decreased, in relation to dosage and duration of treatment. Other endocrine organs were histologically unchanged, but there was involution of the thymus in rats given large doses. Vacuolation occurred in the proximal convoluted renal tubule, without derangement of tubule function. Coincident with the histologically altered zona glomerulosa was a marked reduction in aldosterone levels in the adrenal venous plasma, without significant change in deoxycorticosterone or corticosterone levels. Plasma sodium and potassium values were unchanged. The juxtaglomerular index increased in most animals, but extractable renin, measured by direct bioassay, increased significantly only with maximal dosage of RO1-8307. The findings confirm the hypothesis that heparin and heparinoids with diuretic properties act selectively on the zona glomerulosa to reduce aldosterone secretion, but the exact mechanism remains unknown.