Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.4.3 (phospholipase C)
 18,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The action of 1-pyrene-butyrylcholine, a new cholinergic fluorescent probe, has been studied at the cellular level using electrophysiological and fluorescence techniques. The spectroscopic properties of the probe were found to be similar to those pf pyrene-butyric acid, the excited-state lifetime in air-saturated aqueous solutions being 92 nsec. At micromolar concentrations the probe was found to exert a nondepolarizing, reversible blocking action at the neuromuscular junction of the frog. The same cholinolytic effect was observed in hypersensitive denervated muscles. The synaptic localization of the probe could be observed with fluorescence microscopy using sub- and micromolar concentrations. Treatment of the nerve-muscle preparations with proteolytic enzymes, resulting in the separation of the nerve ending from the muscle end-plate, enabled a distinction to be made between the fluorescence arising from these two parts of the synapse. Intense presynaptic fluorescence was observed, and was not altered by micromolar concentrations of alpha-bungarotoxin, d-tubocurarine, hemicholinium, or cholinesterase inhibitors. Faint reversible staining of the end-plate region was observed in enzymically treated muscles and was inhibited by prior treatment with alpha-bungarotoxin. Fluorescent alpha-toxin revealed similar patterns of fluorescence in the end-plate of enzyme-treated muscles. The postsynaptic localization of the fluorescent probe is therefore tentatively identified as the one producing the cholinolytic effect upon binding to acetylcholine receptor sites.
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PMID:1-Pyrene-butyrylcholine: a fluorescent probe for the cholinergic system. 108 Dec 27

The gene of the mouse V3/V1b receptor was identified by homology cloning. One of the genomic clones contained the entire coding sequence. The cDNA presented high identity with rat (92%) and human (84%) sequences. Southern blot analysis indicated the existence of a single gene. Tissue distribution was studied by RT-PCR. The major site of expression was the pituitary. A faint signal was also present in hypothalamus, brain, adrenal, pancreas and colon. The mouse corticotroph cell line, AtT20, did not express the transcript. In order to confirm the identity of the sequence, the V3/V1b receptor cDNA was cloned and stably expressed in CHO-AA8 Tet-Off cells under the control of tetracycline. When transfected cells were treated with arginine vasopressin (AVP), inositol phosphate production increased in a dose-dependent manner, indicating that the V3/V1b receptor couples to phospholipase C. Moreover, AVP did not stimulate cAMP production. Binding studies with [3H]AVP indicated that the affinity of the mouse V3/V1b receptor (Kd=0.5 nM) is similar to that reported for rat and human receptors. The rank order of potency established in competition binding experiments with different analogues was representative of a V3/V1b profile, distinct from V1a and V2. However, significant differences were found between human and mouse receptors tested in parallel. Thus the pharmacology of V3/V1b receptors can not be transposed among different species.
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PMID:Gene and cDNA cloning and characterization of the mouse V3/V1b pituitary vasopressin receptor. 1034 84