Anthony Garcia, D.D.S.
Education: Bachelor of Science in kinesiology (May 2011)
Master of Science in kinesiology from Kansas State University
Doctor of Dental Surgery from the University of Missouri-Kansas City
McNair Project: Mechanisms Mediating Blood Pressure Complications to Bacillus anthracis toxins (2010)
Mentor: Michael Kenney, Ph.D.
Bacillus anthracis infection is produced by two endotoxins, lethal toxin (LeTx) and edema toxin (ETx). In recent years investigators at the National Institutes of Health have shown that LeTx and ETx produce significant cardiovascular alterations in infected individuals, which play an important role in the lethality of B. anthracis infections. However, the mechanisms by which these alterations, specifically hypotension, occur are still unknown. The sympathetic nervous system (SNS) plays a prominent role in the moment-to-moment regulation of the cardiovascular system during basal conditions, as well as in response to acute and chronic stressors. Despite the important role that the SNS plays in maintaining homeostasis, the effects of LeTx and/or ETx on sympathetic nerve discharge (SND) regulation is not well understood. We hypothesized that LeTx and/or ETx would produce sympathoinhibition, resulting in significant decreases in mean arterial pressure (MAP). There were four groups in which LeTx , ETx, LeTx+ETx, or vehicle was administered via an intravenous infusion in anesthetized Sprague-Dawley rats. SND, MAP and heart rate (HR) responses were measured throughout the experiment. Rats who received LeTx infusions displayed attenuated renal SND responses along with simultaneous decreases in MAP after two hours. The results suggest that LeTx produces sympathoinhibition in infected individuals, which contributes to the hypotensive response.