M: Cardiac sympathetic nerve activity and heart rate during coronary occlusion in awake cats

nerve activity and heart rate durirtg coronary occlusion in awake cats. Am. J. Physiol. 251 (Heart Circ. Physiol. 20): H528-H537, 1986.-Responses in efferent cardiac sympathetic nerve activ-ity (CSNA) and heart rate (HR) to a 100-s anterior descending coronary artery occlusion were measured in cats under awake, atropinized, anesthetized, or anesthetized and atropinized states. In the conscious state, at 20 and 90 s of occlusion, CSNA increased by 23 % and then decreased by 7%, respectively, whereas HR decreased by 5 and 17%, respectively. With atro-pinization and/or anesthesia, the initial increase in CSNA was inhibited and the later decrease in CSNA was enhanced, whereas the bradycardia was diminished. HR changed in pro-portion to CSNA responses with high correlations, i.e., r = +0.89, +0.90, +0.96, and-to.91 for the four states, respectively. In the conscious state, the CSNA-HR relation line shifte