Relationship of blood pressure to renal concentrating defect in hemorrhagic shock

¹ Departments of Surgery and Physiology, Western Reserve University, Cleveland, Ohio

The osmolalities of renal papillary and cortical tissue extracts, urine, and peripheral plasma were measured in Pitressin-loaded dogs in hemorrhagic shock after 1 hr of anuria. The excretion of urine during hypotension was induced by an infusion of mannitol. After 1 hr of anuria at 60 mm Hg mean blood pressure, the renal papilla, cortex, peripheral plasma, and urine were essentially isoosmotic. After 1 hr of anuria at 40 mm Hg, the renal papilla and urine were hypertonic to cortex and plasma. The results indicate that medullary solute washout in hemorrhagic shock is a function of blood pressure, and suggest that the rate of washout is related to the rate of medullary blood flow.

Key Words: kidney • urinary concentrating ability • medullary blood flow

Submitted on January 27, 1965