Primate kidney function in hemorrhagic shock as influenced by dibutyryl cyclic AMP.

Standardized hemorrhagic shock was employed to study alterations in electrolyte and water handling in the owl monkey, either normally hydrated or moderately dehydrated. Increase in fractional clearance of osmolarity,sodium, and calcium occurred with retransfusion after the hypotensive phase. In the hydrated animals, free-water clearance became positive, and the urine-to-plasma osmolarity ratio [(U/P)osM] decreased below 1.0. In the dehydrated animals, free-water reabsorption (TCH2O) decreased but remained negative,while (U/P)osM remained above 1.0. Dibutyryl cyclic AMP (DBcAMP) was infused into the renal arterial supply in an attempt to correct a possible deficiency of cyclic AMP production. In the hydrated group, free-water clearance (CH2O) became more positive with infusion, and (U/P)osM decreased even further, with no effect on fractional sodium clearance. Effects were less or absent in the dehydrated group. Possible explanations for the observed effects of DBcAMP are considered. It was concluded that the loss of concentrating power seen in hemorrhagic shock occurs at a step beyond the production of cyclic AMP by adenylate cyclase.