Laboratory demonstration of baroreflex control of heart rate in conscious rats.
We have developed a laboratory exercise that demonstrates arterial baroreflex control of heart rate (HR) in the conscious unrestrained rat, incorporating graduate level physiological topics as well as a hands-on exposure to conscious animal research. This demonstration utilizes rats chronically instrumented to measure cardiac output (CO), HR, and arterial blood pressure in response to agents that raise or lower blood pressure. The HR response to progressive increases or decreases in blood pressure is recorded, and a baroreflex curve is generated by plotting mean arterial blood pressure (MABP) vs. HR. Observation of altered CO allows for discussion of the relationship between MAP, CO, HR, stroke volume, and total peripheral resistance. Administration of arginine vasopressin demonstrates the ability of this hormone to alter the sensitivity of the baroreflex. Throughout the demonstration, students answer questions from a handout about general cardiovascular physiology, specific pathways of agonists, and the baroreflex system, encouraging group and individual critical analysis of the results. Interpretation of the data reemphasizes lecture material and allows students to observe the baroreflex response in a physiological setting.
O'Donaughy
Theresa L
TL
Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131, USA.
Resta
Thomas C
TC
Walker
Benjimen R
BR
D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology; D017704:Baroreflex / Q000187:drug effects / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D004521:Educational Measurement; D006339:Heart Rate / Q000502:physiology*; D007753:Laboratories; D008297:Male; D010827:Physiology / Q000193:education*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013663:Teaching
D001127:Arginine Vasopressin