Microinjection of substance P and ACh into rat intermediolateral nucleus elicits cardiovascular responses

Microinjection of substance P and ACh into rat intermediolateral nucleus elicits cardiovascular responses. Am. J. Physiol. 259 (Regulatory Integrative Comp. Physiol. 28): R357-R361, 1990.-The effects of substance P (SP) or acetylcholine (ACh) microinjected into the intermediolateral nucleus of the spinal cord (IMLn) on arterial pressure (AP) and heart rate (HR) were investigated in 22 male Wistar rats under urethan and artificial ventilation. L-Glutamate (Glu) was microinjected into the IMLn between C7 and Tq to locate cardiovascular sites. Micropipettes containing Glu were stereotaxically positioned in 82 histologically verified sites in the IMLn between C7 and Tq on both the right and left sides. Microinjection of 4-10 nl of 0.18 M Glu in 30 of 39 explored sites at the TZ level elicited significant increases in HR (+24.2 t 3.1 beats/min). These changes were accompanied by significant increases in mean A