Altered Cardiovascular Responses to Glutamate and Acetylcholine Microinjected into the Nucleus Tractus Solitarii of the SHR

Abstract

L-glutamate (GLU) or acetylcholine (ACh) injected into the nucleus tractus solitarii (NTS) of rat elicits a decrease in arterial pressure (AP) and heart rate (HR) similar to that seen with activation of the baroreflex. Both compounds may play a role in the mediation of the baroreflex at the level of NTS. The baroreflex may be disturbed in the spontaneously hypertensive rat (SHR). Thus we sought to determine if the dose-related responses to microin-jection (50 nl) of the two putative transmitters into NTS may be altered in

Key Words:

• acetylcholine
• baroreflex
• glutamate
• nucleus tractus solitarii
• spontaneously hypertensive rat