Bacillus anthracis lethal toxin induces complex changes in sympathetic nerve discharge regulation

Bacillus anthracis lethal toxin (LeTx) alters blood pressure and visceral sympathetic nerve discharge (SND) regulation (Garcia et al., 2012). The present results indicate that LeTx infusions produce similar response profiles in peripheral (lumbar) and visceral (renal) SND; an initial widespread activation of sympathetic nerve outflow, followed by a generalized reduction in lumbar and renal SND from peak levels, although the sympathoinhibition tended to be attenuated in lumbar SND. Combined hypoxia + hypercapnia during the hypotensive phase of LeTx infusions increased lumbar and renal SND, indicating that sympathetic neural circuits can be activated during the circulatory shock phase of B. anthracis septicemia.