Abstract
The effects of preganglionic sympathetic nerve stimulation and exogenous agents upon vascular tone were observed in hindlimb preparations of pithed adult bullfrogs. Repetitive electrical stimulation of the sympathetic C, but not the B, system elicited arterial vasoconstriction and reduced blood flow in vascular beds supplying the sartorius muscle and the skin. Close-arterial injections of epinephrine and neuropeptide Y each mimicked neurogenic vasoconstriction. After close-arterial injection of phentolamine, an α-adrenergic antagonist, the maximal effects of nerve stimulation were delayed in onset and reduced in magnitude, but not eliminated. Pretreatment with phentolamine blocked the vasoconstriction caused by injection of epinephrine, and produced a mild reduction in responses to neuropeptide Y. These observations demonstrate the vasomotor function of the sympathetic C system and they support the hypothesis that neuropeptide Y and epinephrine function as cotransmitters in postganglionic C neurons.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
