Lymph and intrarenal venous blood as indicators of canine renal cortical function

Samplings of canine capsular and hilar lymph, and intrarenal venous blood were investigated as in vivo techniques for detecting renal cortical function in control and NH4Cl pretreated anesthetized animals. The glucose concentration of capsular, but not hilar, lymph was indicative of cortical drainage in both groups. When lymph flow was increased by elevating renal venous pressure, capsular lymph glucose concentration reflected cortical function only in the NH4Cl animals. The glucose concentration of intrarenal venous blood indicated cortical drainage in both the control and NH4Cl animals but the cortical function of a high para-aminohippuric acid extraction was only detectable in the NH4Cl group. Conclusions are that sampling of capsular lymph and intrarenal venous blood may prove to be useful techniques for studying certain in vivo cortical functions but the intrarenal venous technique is less sensitive than capsular lymph collection.