A variety of evidence now suggests that excitatory amino acid receptors mediate the effects of light on the circadian system of mammals. However, the ACh agonist carbachol is the only agent that has been reported to "mimic" the phase-shifting effects of light in vivo. Because the other published evidence for the involvement of ACh in light-mediated phase shifts is weak, we have referred to this...

Synergistic insulin release is observed in combination with muscarinic agonist and glucose. In order to define the role of changes in the cytoplasmic free Ca2+ level ([Ca2+]i), the effect of combination with carbachol and glucose on both phosphoinositide breakdown in rat pancreatic islets and [Ca2+]i dynamics in single fura 2-loaded B-cells was investigated. When the islets were prelabeled with...

It is important to clarify developmental mechanisms of desensitization because of their great significance in regulation of cellular responsiveness. We have found that carbachol-induced desensitization to carbachol develops in three successive phases in the presence of extracellular Ca(2+) in the smooth muscle of guinea pig taenia caeci: fast desensitization within 15 s, transient resensitizati...

The signalling pathway leading to an activation of mitogen-activated protein (MAP) kinase subtypes Erk-1 and -2 upon stimulation of muscarinic receptor with carbachol in human neuroblastoma SK-N-BE2(C) cells was investigated. Carbachol activated Erk-1/-2 by stimulating M3 muscarinic receptor, as determined by specific antagonists for individual muscarinic receptors. The activation of Erk-1/-2 b...

Muscle contraction stimulates glucose uptake acutely to increase energy supply, but suitable cellular models that faithfully reproduce this complex phenomenon are lacking. To this end, we have developed a cellular model of contracting C(2)C(12) myotubes overexpressing GLUT4 with an exofacial myc-epitope tag (GLUT4myc) and explored stimulation of GLUT4 traffic by physiologically relevant agents....

Inositol 1,4,5-trisphosphate (IP3) stimulates Ca2+ release from the endoplasmic reticulum (ER), and the response is potentiated by 3',5'-cyclic AMP (cAMP). We investigated this interaction in HEK293 cells using carbachol and parathyroid hormone (PTH) to stimulate formation of IP3 and cAMP, respectively. PTH alone had no effect on the cytosolic Ca2+ concentration, but it potentiated the Ca2+ sig...

We have previously reported that carbamoylcholine (carbachol), a recognized inhibitor of somatostatin release from D-cells, can act as stimulant following pretreatment of cells with pertussis toxin. In the present studies we have observed that pertussis toxin reverses the inhibitory effects of carbachol on D-cell stimulated with either cAMP or 12-O-tetradecanoyl-phorbol 13-acetate. Furthermore,...

introduction: previous studies have shown that stimulation of lateral hypothalamus (lh) produces antinociception. orexin-a (oxa) receptor is strongly expressed in the nucleus locus coeruleus (lc) and orexinergic fibers densely project from lh to lc. in this study, we assessed the role of lc and its oxa receptors in antinociceptive response induced by lh chemical stimulation in the rat. methods:...

The effects of the muscarinic agonist carbachol, histamine and bradykinin on incorporation of [3H]inositol into the phosphoinositides and the formation of [3H]InsPs were examined in bovine tracheal smooth-muscle (BTSM) slices labelled with [3H]inositol. These agonists result in substantial and dose-related increases in the incorporation of [3H]inositol into the phospholipids. Carbachol and hist...

The effects of extracellular ATP on ion fluxes and the intracellular free Ca2+ concentration ([Ca2+]i) were examined using a suspension of rat parotid acinar cells and were contrasted with the effects of the muscarinic agonist carbachol. Although ATP and carbachol both rapidly increased [Ca2+]i about threefold above the resting level (200-250 nM), the effect of ATP was due primarily to an influ...