Two antihypertensive lipids can be derived from the renal papilla, the antihypertensive polar (APRL) and the antihypertensive neutral (ANRL) renomedullary lipid. The renal venous effluent of the undipped kidney contains both ANRL and APRL. This effluent lowers the arterial pressure (AP) of the normal rat when infused i.v. As it lowers the AP the heart rate (HR) and sympathetic nerve activity (S...

Renal perfusion was increased in anesthetized rabbits and dogs by using an extracorporeal circuit. When left kidney perfusion pressure was raised in rabbits (145-240 mm Hg), arterial pressure fell by 1.34 +/- 0.20 mm Hg/min. Pretreatment of the rabbits with 2-bromoethylamine hydrobromide, which destroyed the renal medulla, abolished the fall in arterial pressure (-0.08 +/- 0.08 mm Hg/min) in re...

We investigated the relation between renal perfusion pressure and the release of a renal vasodepressor substance in vivo to determine whether this substance was released at physiological pressures. We perfused the left kidneys of anesthetized rabbits using an extracorporeal circuit that allowed renal perfusion pressures to be set at 65 mm Hg (control) and increased to 95, 125, 155, or 185 mm Hg...