Demonstration of a depressor substance in serum from CCl4 treated rats

Previous studies have shown that blood pressure was reduced in rat experimental hypertension following a series of carbon tetrachloride (CCl4) injections. To define this effect more precisely the presently reported experiments were done. Serum from rats treated with CCl4 was injected into various recipients. The mean systolic blood pressure of renal hypertensive recipients decreased significantly at 60 minutes by -15 mm Hg. In normotensive and spontaneous hypertensive rat recipients the pressure did not fall. It is concluded that a vasodepressor substance appears in the serum of CCl4 treated rats which affects only renal hypertensive recipients.