Role of the glycine sensitive area in the regulation of cardiac output

Publisher Summary This chapter describes the role of glycine sensitive area (GSA) in the regulation of cardiac output. By using glycine as a tool, it is possible to localize more precisely, within the areas covered by perspex rings, the structures responsible for the maintenance of blood pressure. In these experiments, glycine was applied either unilaterally or bilaterally. The unilateral electrolytic destruction of a small area within the left ring only produced a small blood pressure drop, but it potentiated the effect of glycine unilaterally applied to the opposite side. Bilateral electrolytic destruction of this glycine sensitive area produced a fall in arterial blood pressure to levels similar to those usually obtained in acute spinal animals, without the signs of recovery for at least six hours, which was the longest period of time the animals were observed for. The results obtained with pharmacological manipulation of the glycine sensitive area are a strong indication that this area controls CO, in addition to its well-known role in the control of mean arterial blood pressure, total peripheral resistance, and heart rate. This control is exerted most probably through the sympathetic innervation to the heart affecting its contractility.