[The cytochemical characteristics of the epithelium of the proximal nephron and of the endothelium of the peritubular capillaries and kidney functional status in chronic glomerulonephritis patients].

To assess the role of metabolic shifts in pathogenesis of excretory renal dysfunction arising in chronic glomerulonephritis (CGN), two groups of patients were considered. Fourteen patients of group 1 had CGN in a preazotemia stage, thirteen patients of group 2 died of CGN-induced uremia. Cortical nephrobiopsies obtained intravitally (group 1) and renal tissue specimens obtained at autopsies during postmortal hours 0-2 (group 2) were investigated. Apical epithelium of proximal canaliculi in group 1 showed higher levels of acid phosphatase (AP), though much lower of succinate dehydrogenase (SDH) and lactate dehydrogenase (LDH) compared to group 2. In basal proximal nephrothelium of group 1 the activity of LDH and AP was inhibited against these values in group 2. The activity of NADPN2-dehydrogenase, SDH and AP in group 1 surpassed that in group 2 in endothelium of renal cortex peritubular capillaries. These structures LDH and AP proved more active in group 1. The authors observed a series of significant multidirectional correlations between the activity of the enzymes studied and renal excretion. The growing activity of NADN2-dehydrogenase and AP was associated with diminution of electrolyte and water excretion, while enhancing LDH activity exhibited the opposite effect. It is concluded that progression of cortical disorders in the kidneys of CGN patients entails serious metabolic derangement reflected by imbalance in aerobic and anaerobic metabolism. These biochemical shifts result in ambiguous functional sequelae and may contribute both to renal retention of fluid, electrolytes and their excretion. The latter is likely a compensatory mechanism involved in maintenance of water-salt homeostasis in relevant patients.