title: Pineal muscarinic phosphoinositide response: pertussis toxin resistant signaling with very low receptor number.
abstract: Autoradiography revealed very low density of muscarinic receptors in the rat pineal gland. Yet, the magnitude of phosphoinositide hydrolysis elicited with 0.1 mM carbachol was similar to that seen with 1 mM norepinephrine. The cholinergic and adrenergic phosphoinositide responses were fully additive. The cholinergic signal was insensitive to pertussis toxin both in vivo and in vitro and persisted in pineals cultured for 5 days. The data expand our previous finding on functional muscarinic acetylcholine receptors in the rat pineal gland.
authors.affiliation: Laboratory of Clinical Science, National Institute of Mental Health, Bethesda, MD 20892.
authors.forename: J T
authors.initials: JT
authors.lastname: Laitinen
authors.forename: T
authors.initials: T
authors.lastname: Torda
authors.forename: J M
authors.initials: JM
authors.lastname: Saavedra
mesh_terms: D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology*; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology*; D009924:Organ Culture Techniques; D037342:Pertussis Toxin; D010716:Phosphatidylinositols / Q000378:metabolism*; D010870:Pineal Gland / Q000187:drug effects / Q000378:metabolism*; D010890:Pirenzepine / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011976:Receptors, Muscarinic / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
chemical_list: D010716:Phosphatidylinositols; D011976:Receptors, Muscarinic; D010566:Virulence Factors, Bordetella; D010890:Pirenzepine; D001285:Atropine; D002217:Carbachol; D037342:Pertussis Toxin; D009638:Norepinephrine; D011224:Prazosin