Efferent vascular patterns and early vascular-tubular relations in the dog kidney.

BEEUWKES, REINIER III. E$ erent vascular patterns and early vasculartubular relations in the dog kidney. Am. J. Physiol. 221(5): 1361-1374. 197 1 .-Glomerular efferent vascular patterns were studied in cleared dog kidneys injected with silicone rubber. In addition, to show vascular-tubular relations, kidneys were perfusion-fixed in vivo and their vasculature was filled with silicone rubber. Proximal tubules were then injected by means of micropipets inserted into the urinary spaces of glomeruli in cleared slices of the fixed kidneys. Ten efferent vascular patterns including two subcapsular, four midcortical, and four inner cortical patterns are described. Close association between the efferent capillary network and proximal tubule of the same glomerulus was found only in the subcapsular cortex. In the bulk of the cortex, proximal tubules were found to be dissociated from the efferent vessels of the same glomerulus. Hence, it appears that the proximal tubules accessible to micropuncture have vascular-tubular relations different from proximal tubules in the bulk of the cortex. Furthermore, close association between the proximal tubule and efferent vascular network of the same glomerulus should not be assumed in proposed mechanisms of glomerular-tubular balance.