[Interstitial cells of the renal medulla in rats with genetic spontaneous hypertension].

Electron microscopic studies of interstitial cells (IC) of the renal medulla inspontaneously hypertensive rats (SHR) were carried out. Morphometric analysis revealed no differences in the total volume of the lipid granules of IC in the 1 1/2-month-old SHR and control Wistar rats; one-year-old SHR showed an increased volume of granules, IC of SHR displayed hypertrophy and hyperplasia of both the rough and the smooth endoplasmic reticulum and the Golgi complex, especially marked at the early stage of hypertension. Apparently the state of ultrastructures of the synthesis and secretion should be accepted as a criterion for the assessment of the IC function, at least in arterial hypertension, but not the degree of decreased lipid granularity as supposed formerly.