KIDNEY AND BLADDER CALCULI IN SPONTANEOUSLY HYPERTENSIVE RATS

  • 1 January 1981
    • journal article
    • research article
    • Vol. 62  (4) , 369-374
Abstract
Naturally-occurring kidney stones are rare in animals. The Japanese strains of spontaneously hypertensive rats (SHR) are normotensive at birth but develop high blood pressure, hyperglycemia and hyperlipidemia as they mature. The SHR strain is prone to develop kidney stones. A unique sub-strain of SHR was developed in which some animals develop hypothalamic obesity concomitantly with their rising blood pressure, i.e., obese/SHR. The obese/SHR characteristically develop microscopic kidney stones which become detached at an early stage of formation, migrate to the bladder and grow by concretion into huge, rounded calculi. The stone nidus starts as a subepithalial cyst-like focus containing edema, colloidal acidic mucoprotein and red and white blood cells suspended on a delicate network of fibrils. The nidi grow by concretion of an admixture of Ca and acidic protein in a lamellar arrangement. The disparate morphogenesis and anatomic location of kidney stones in obese as opposed to non-obese/SHR suggest that calculus formation may be governed by specific differences in genetic programming. The incidence of kidney stones parallels the severity and chronicity of the hypertension in SHR, non-obese and obese/SHR and the Cushingoid habitus in the obese/SHR.