Abstract

1. Release of VIP from the submaxillary gland, in response to stimulation of the chorda tympani, and its vasodilator action at the site of release have been investigated in anaesthetised cats. 2. Chorda stimulation at 20 Hz produced an abrupt rise in the concentration of VIP in the submaxillary venous effluent plasma, accompanied by a substantial increase in submaxillary blood flow, in the presence or absence of atropine. 3. Intra-arterial infusions of VIP which reproduced the rise in submaxillary venous plasma concentration that occurred during chorda stimulation at 20 Hz, also produced a rise in submaxillary blood flow of the same order of magnitude. 4. Direct comparison of the responses of the submaxillary vasculature to intraarterial infusions of VIP, ACh and bradykinin showed that the vasodilator potency of VIP far exceeded that of either of the other agonists. 5. Intra-arterial infusion of ACh, sufficient to elicit a maximal submaxillary vasodilator response, caused no detectable release of VIP from the gland. 6. The results are discussed in relation to the proposition that VIP is released from post-ganglionic parasympathetic neurones, in the submaxillary gland of the cat, and acts, as a transmitter, to cause vasodilatation, which is resistant to atropine.

Full Text
Paper version not known

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 call

Disclaimer: 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.