Role of the Splanchnic Nerve and the Adrenal Medulla in the Genesis of ‘Preoptic Pulmonary Edema’

¹ From the Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington

The pulmonary edema which follows preoptic lesions in rats is prevented by antecedent bilateral section of the splanchnic nerves. Intravenous epinephrine in doses exceeding 0.0125 mg/100 gm body weight causes fatal lung edema in rats comparable to that produced by preoptic lesions. Moreover, extracted pressor amines from rat adrenal glands cause lung edema, often fatal, when injected into the donor or into intact rats. However, adrenal demedullation does not prevent lung edema following preoptic lesions. Hence the protective effect of splanchnectomy against preoptic lesions is not wholly due to adrenal denervation. It is tentatively suggested that preoptic lung edema results from overloading of the pulmonary circuit owing to splanchnic mediated constriction of visceral venous reservoirs. Liver and spleen weights of animals dying from preoptic lung edema were significantly less than normal.