Role of sympathetic nerve and adrenal gland in the potentiation of hypoxic pulmonary vasoconstriction during cigarette smoking.

The aim of this study was to investigate the role of sympathetic nerve and adrenal gland in the changes in hemodynamics and hypoxic pulmonary vasoconstriction (HPV) induced by cigarette smoking in Wistar rats. Data showed that an increment of pulmonary vascular resistance (PVR) induced by alveolar hypoxia was partially prevented by prazosin (alpha 1-receptor blocker) and prazosin combined with propranolol (beta-receptor blocker), but not significantly affected by propranolol or adrenalectomy. Cigarette smoking could increase PVR and potentiate HPV, whereas the potentiation of HPV was partially inhibited by prazosin and strengthened by propranolol, but not affected by adrenalectomy. It is suggested that the sympathetic nerve excitation caused by cigarette smoking may play a role in the strengthening of HPV.