[The renal systems regulating water-electrolyte balance in the nephrotic syndrome]

A study was made of the role of renal factors regulating water and sodium balance in the body in chronic nephritis of the nephrotic type. 120 patients with the nephrotic syndrome were examined at different phases of its formation, namely at the phase of edema increase, stabilization phase, and at the phase of edema reduction. The rate of glomerular filtration and its relation to sodium excretion were defined. A significant decrease of glomerular filtration was identified at the phase of edema increase as was its rise at the phase of edema stabilization. A study was made of the activity of the hormonal systems regulating sodium reabsorption in the canaliculi, namely of aldosterone, the renin-angiotensin system, and renal prostaglandins. To specify the role of the hormonal systems, investigations were performed under the conditions of blocking aldosterone synthesis with heparin and blocking of prostaglandin synthesis with indomethacin. It has been revealed that inhibition of glomerular filtration is the crucial factor in sodium retention at the phase of edema increase. Enhancement of sodium reabsorption in the canaliculi is related to excess production of aldosterone and inadequate production of renal prostaglandins. Activation of the renin-angiotensin system does not play any material role in the formation of the nephrotic syndrome.