The Reno-Hepatic Axis of Blood Pressure Control: Further Studies

A reno-hepatic axis of blood pressure (BP) control has been proposed primarily by two developments: (1) the lag period between the injection of the antihypertensive neutral renomedullary lipid (ANRL) into the vena cava and the beginning of the drop of the BP is significantly reduced by injection of this lipid into the portal vein; and (2) a reno-portal shunt (RPS) accelerates markedly the drop of the BP following unclipping the Goldblatt hypertensive rat. In the present studies, three maneuvers were performed: (1) perfusion of the isolated, blood-drained rat liver with plasma containing ANRL and delivery of the plasma into the jugular vein of a hypertensive rat; (2) injection of captopril, establishment of a RPS of a hypertensive rat (one-kidney, one-clip) followed by unclipping; and (3) establishment of a RPS in a normal rat. The blood-drained liver was capable of decreasing significantly the lag period of ANRL. Captopril did not potentiate the antihypertensive action of the kidney when RPS was coupled with unclipping. Following the RPS, the BP of the normal rat dropped modestly over a 3-hour period. These results further support the concept of reno-hepatic axis of BP control.