Chemical sympathectomy and postganglionic nerve transection produce similar increases in galanin and VIP mRNA but differ in their effects on peptide content.

Large changes in neuronal gene expression occur in adult peripheral neurons after axonal transection. In the rat superior cervical ganglion, for example, neurons that do not normally express vasoactive intestinal peptide (VIP) or galanin do so after postganglionic nerve transection. These effects of axotomy could result from a number of aspects of the surgical procedure.

Effects of colchicine application to preganglionic axons on choline acetyltransferase activity and acetylcholine content and release in the superior cervical ganglion.

These experiments investigate the effect of block, by colchicine, of fast axonal transport in the cat's cervical sympathetic trunk (CST) on the superior cervical ganglion's choline acetyltransferase (ChAT) enzyme activity, acetylcholine (ACh) content, and ACh release. Electron microscopy on the segment of the CST exposed to colchicine 1 or 4 days earlier showed disappearance of microtubules and accumulation of vesicles and smooth membrane tubules but no disruption of the axonal cytomatrix. At 4 days following colchicine treatment, the number and size of synaptic boutons per grid square in the ganglion ipsilateral to the colchicine-treated CST were similar to those in the control ganglion.

Long-term depression of a sympathetic ganglionic response to opioids by prolonged synaptic activity and by phorbol esters.

We studied the effect of the adenylate cyclase activator forskolin, of protein kinase C-activating phorbol esters and of prolonged preganglionic input activation on the inhibitory response of the perfused superior cervical ganglion of the cat to exogenous met-enkephalin (Met-ENK). Met-ENK inhibited, in a concentration-dependent manner, the postganglionic compound action potential evoked by cervical sympathetic trunk stimulation. The inhibition was reversible, was blocked by naloxone as well as by pertussis toxin and showed no homologous desensitization in the concentration range 0.

Vasoactive intestinal peptide and impotence in experimental diabetes mellitus.

Objective: To determine whether a defect in vasoactive intestinal peptide (VIP)-mediated vasodilatation underlies diabetic impotence.

Materials And Methods: Rats treated with streptozotocin for 8 weeks developed diabetes, as shown by hyperglycaemia and glycosuria, and had significant impairment of sexual function, as determined by tests of sexual behavior. The VIP content of the penis and major pelvic ganglion, the VIP release by the penis in vitro and the responsiveness of the vasculature of the penis in vivo to intracavernous VIP injection were determined.

Pirenzepine-sensitive component of forelimb vascular resistance and heart rate in cats.

In vagotomized, midcollicular decerebrate, non-anesthetized cats, in which the preganglionic input to the stellate ganglion was intact and the right forelimb was autoperfused at constant flow, the muscarinic receptor antagonist pirenzepine (PZP, 50 micrograms/kg i.v.), which does not cross the blood-brain barrier, produced a decrease in forelimb perfusion pressure (FLPP), heart rate (HR) and systemic arterial pressure (SAP).