title: Acetylcholine-induced responses in the salivary gland cells of Helisoma trivolvis.
abstract: This study describes the actions of acetylcholine (ACh) on the salivary gland cells of Helisoma. Perfusion of the salivary gland cells with ACh produces a long-lasting depolarization accompanied by an increase in the input conductance of the gland cells. The depolarization is often followed by a long-lasting hyperpolarization. Carbamylcholine, tetramethylammonium, and choline also produce depolarizing responses. Nicotine and pilocarpine produce only a small depolarization in the gland cells. The following cholinergic antagonists are effective in blocking the gland-cell response to ACh: tetraethylammonium, atropine, hexamethonium, d-tubocurarine, and strychnine. A new preparation, the "isolated acinus," was utilized to obtain the reversal potential of the ACh response. The mean reversal potential in 10 preparations was -7 +/- 8 mV. The depolarizing phase of the response is dependent on the presence of both external calcium and external sodium ions. The long-lasting hyperpolarization is produced by the activity of an electrogenic sodium-potassium pump. The properties of the acetylcholine receptors on the salivary gland cells of Helisoma are compared with those described in other gastropod preparations.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002794:Choline / Q000494:pharmacology; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D004553:Electric Conductivity; D066298:In Vitro Techniques; D008974:Mollusca / Q000502:physiology*; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D012469:Salivary Glands / Q000187:drug effects / Q000502:physiology
chemical_list: D002800:Cholinesterase Inhibitors; D000644:Quaternary Ammonium Compounds; D002217:Carbachol; C027917:tetramethylammonium; D002794:Choline; D000109:Acetylcholine