Vascular responses produced by histamine by ion transfer

The vascular effects of histamine by ion transfer were studied in the hand and/or forearm of 25 normal subjects, using the venous occlusion plethysmographic method. Consistently a marked increase in blood flow was elicited in the hand and a lesser, but still considerable, augmentation occurred in the forearm. Histamine by ion transfer to the hand and foot produced significant vasodilatation in an opposite forearm, thus supporting the view that the drug is absorbed into the systemic circulation to affect distant vascular structures. Further evidence for such a belief was the flushing of the face and neck, associated with very little alteration in blood pressure and pulse rate. As a vasodilating agent, histamine by ion transfer was found to compare more than favorably with such agents as Mecholyl by ion transfer, ultrasound, short-wave diathermy, reflex vasodilatation, and wet heat. Submitted on September 10, 1962