Transmission of hypertension in rats by cross circulation

Cross circulation was performed in 54 couples of spontaneously hypertensive and normotensive rats. Blood was pumped through two anastomoses between the carotid arteries and external jugular veins in both directions with equal flow rate. In normotensive rats cross-circulated with untreated spontaneously hypertensive rats mean arterial pressure increased by 20.9 +/- 12.2 mm Hg (p less than 0.01). Administration of digoxin antibody in a dose binding 0.25 mg digoxin to the spontaneously hypertensive rats before cross circulation prevented the transmission of hypertension to the normotensive rat, whereas chemical sympathectomy with 6-hydroxydopamine and intravenous injection of inactive Fab fragments had no inhibitory effect. It is concluded that, in this strain of spontaneously hypertensive rats, a circulating hypertensive factor exists. The factor binds to digoxin antibody and is not produced in sympathetic nervous tissue.