Adrenal blood flow in the albino rat

The cardiac output fractionation technique employing Rb86 or iodoantipyrine (I131) has been applied to the study of adrenal blood flow in the rat. Either indicator is suitable for the measurement of adrenal blood flow: this is indicated by constancy of label uptake during the first 30 seconds after its administration in a single intravenous injection; when given together the same fraction of each indicator is taken up by the gland. The adrenal flow fraction is 0.14% of the cardiac output in 200–275-gm female rats, corresponding to a flow of 0.078 ml/min. or 1.9 ml/gm/min. The value is increased 114% by ACTH. Ligation of one common carotid artery increases the value 80%. Laparotomy and dissection around the adrenal gland produce irregular changes in adrenal blood flow. The significance of these findings for the ‘normal’ adrenal blood flow is discussed.