Heptanol and 18 beta-glycyrrhetinic acid (18 beta GA) block gap junctions, but have other actions on transmitter release that have not been characterised. This study investigates the prejunctional and postjunctional effects of these compounds in guinea pig and mouse vas deferens using intracellular electrophysiological recording and confocal Ca(2+) imaging of sympathetic nerve terminals. In mic...

The vas deferens has been used as a model for many diverse studies of different aspects of autonomic neurotransmission since its introduction including, in particular, sympathetic cotransmission involving release of ATP and neuropeptide Y together with noradrenaline and prejunctional and postjunctional neuromodulation. It has also been used to study sympathetic reinnervation following vasectomy...

Subtype-selective muscarinic antagonists effects on carbachol-induced and electric field-stimulated contractility of rat bladder were compared in vitro. Schild plot analysis of cumulative carbachol dose-response curves in the presence of antagonists was consistent with M3-mediated bladder contractions. However, nerve-evoked contractions were inhibited 15% at 30 Hz ( P < 0.01) by 10 nM pirenzepi...

Changes in the sensitivity of the rabbit ear artery to exogenous norepinephrine and potassium and to sympathetic nerve electrical stimulation were examined in vitro following decentralization which was performed by removing the unilateral preganglionic nerve proximal to the superior cervical ganglion. The contralateral side was left intact as a control. The postjunctional supersensitivity to ex...

A prejunctional mechanism involving an a,-adrenergic receptor may exert control on the release of acetylcholine from parasympathetic nerve endings in the heart. To test this hypothesis in vivo, rats were prepared for electrical stimulation of the vagus nerves. Blood pressures and heart rates were monitored, and the animals were treated with a-agonists and a-antagonists. The a,-selective agonist...

The effect of sympathectomy on parasympathetic regulation of ocular perfusion was investigated. Uveal blood flow through the vortex veins was measured by laser Doppler flowmetry during electrical stimulation of the superior salivatory nucleus, which activates ocular parasympathetic nerves, in adult rats with intact innervation and 2 days or 6 weeks after excision of the ipsilateral superior cer...