[Endocrine system of the kidneys in nephrogenic arterial hypertension: functional and morphological analysis]

The renin-angiotensin (juxtaglomerular apparatus--JGA) and prostaglandin [interstitial cells (IC) of renal medulla and nephrocytes of collecting tubules (NCT)] systems of the kidneys were studied in 72 patients (renal biopsies, nephrectomy, morphofunctional correlations) with the nephrogenic arterial hypertension (vasorenal hypertension, chronic glomerulonephritis, pyelonephritis). Histological and electron-microscopic methods were used; the renin activity was determined in the peripheral blood and blood from the renal veins. The results were analysed mathematically and statistically using an original programme. It is shown that stereotype cyclic changes develop in the endocrine renal system of patients with renal hypertension and they reflect the stages of initial hyperfunction (ultrastructural hyperplasia of JGA cells with appearance of numerous immature granules; ultrastructural moderate hyperplasia of medulla IC; increase of blood renin activity), discoordination of functions (progressing JGA hyperfunction and depletion of prostaglandin synthetic function of medulla IC; compensatory activation of NCT; further increase of the blood renin activity) and depletion (atrophy and fibroblastic transformation of the JGA of the majority of nephrons and of medulla IC). The stages of renal endocrine system alterations in the arterial hypertension are the manifestation of compensatory and adaptive response. Morphofunctional analysis with the use of morphometry and mathematical statistics are necessary for the objective evaluation of this response.