Changes in AdSNA and arterial catecholamines to coronary occlusion in cats

Abstract

The relationship between adrenal (preganglionic) sympathetic nerve activity (AdSNA), cardiac sympathetic nerve activity (CSNA), and arterial catecholamines, i.e., epinephrine (Epi) and norepinephrine (NE), were analyzed during 200 s of occlusion of left anterior descending coronary artery in anesthetized cats. With coronary occlusion, AdSNA maximally increased to 168 +/- 20% (mean +/- SE) of the control value at 20 s and gradually decreased to 149 +/- 10% at 200 s. Mean CSNA (MCSNA), mean arterial pressure, and heart rate decreased significantly because of coronary occlusion. Arterial NE and Epi progressively increased from 0.54 +/- 0.05 and 0.29 +/- 0.03 ng/ml to 1.41 +/- 0.16 and 0.59 +/- 0.08 ng/ml at 3 min after the onset of occlusion, respectively. The correlation between AdSNA and arterial Epi (r = 0.71; P less than 0.01) and between AdSNA and arterial NE (r = 0.57; P less than 0.05) were significant, but the correlation between CSNA and arterial NE was not significant. On the other hand, in adrenalectomized cats, the increases in arterial Epi and NE did not appear during coronary occlusion. We concluded that, with coronary occlusion, AdSNA increased and, in turn, caused an increase in arterial Epi and NE.