[Quantitative relationship of renal blood flow with size and density of glomeruli in rat postnatal ontogenesis]

The aim of the study was to find the quantitative relationship of postnatal changes in the glomeruli anatomic structure with the blood flow in kidneys. Kidney development was studied in 4-, 12-, 30-, and 65-day-old Wistar rats. Diameters of glomerulus (Dgl, microm), afferent and efferent arterioles (Daf and Def), and the glomeruli density (Ngl, mm(-3)) were measured posthumously. Volumes of one ((see text of symbol))V gl, microm3) and all glomeruli (see text for symbol)(sigma(see text for symbol)Vgl, mm3/cm3) and the glomeruli arterioles lumen (Saf and Sef, microm2) were calculated. The renal specific blood flow (SBF per unit of kidney weight, KW) was measured by the laser-Doppler flowmeter (in perfusion units, p.u.) under sodium barbamyl narcosis. We have found that, during postnatal growth, glomeruli morphological parameters vary according to the equations: Dgl = 7.1 (see text for symbol) KW0.41, (see text for symbol)V gl = 187 (see text for symbol) KW1.23, Ngl = 5309 (see text for symbol) KW-0.63 (KW, mg and for one kidney), Saf = 1.1 (see text for symbol)V gl 0.35, and Sef = 6.3 (see text for symbol) V gl 0.14. The renal SBF in 4-, 12-, and 65-day-old rats increases according to SBF = 6.7 (see text for symbol) (sigma( see text for symbol)V gl)0.98. The renal SBF calculated per unit of glomeruli volume varies a little with age.