Identification of functional receptors for vasoactive intestinal peptide and neurotensin in the human submandibular gland duct cell line, HSG-PA.
The HSG-PA human submandibular gland adenocarcinoma cell line has attracted attention recently as a potentially useful cell culture model for studies of salivary duct cell function and regulation. These cells possess a variety of morphological and biochemical markers found in salivary duct cells. Recently, muscarinic cholinergic receptors coupled to inositol intracellular Ca2+ mobilization (He et al., Eur. J. Physiol., 413 (1989) 505-510) and K+ fluxes (Ship et al., Am. J. Physiol., 259 (1990) C340-C348) have been identified in HSG-PA cells. In this study, we report the presence in these cells of functional receptors for two neuropeptides, vasoactive intestinal peptide (VIP) and neurotensin. Receptors for both peptides were labeled in intact cell radioligand binding studies and exhibited pharmacological profiles similar to receptors found in other tissues. There was close agreement between binding Ki values and the ED50 values for stimulation of second messenger production and modulation of K+ efflux, with all values between 1 and 5 nM. Whereas neurotensin stimulated K+ efflux dramatically, VIP alone had no effect but enhanced the response to neurotensin. These studies thus represent the initial documentation of functional receptors for VIP and neurotensin in a cell line of salivary duct cell origin.
Turner
J T
JT
Department of Pharmacology, School of Medicine, University of Missouri-Columbia 65212.
Yu
H
H
D000230:Adenocarcinoma / Q000737:chemistry; D002118:Calcium / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006801:Humans; D009496:Neurotensin / Q000378:metabolism / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism; D011964:Receptors, Gastrointestinal Hormone / Q000378:metabolism*; D018028:Receptors, Neurotensin; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D018005:Receptors, Vasoactive Intestinal Peptide; D013365:Submandibular Gland Neoplasms / Q000737:chemistry* / Q000473:pathology; D014407:Tumor Cells, Cultured; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism / Q000494:pharmacology
D011964:Receptors, Gastrointestinal Hormone; D018028:Receptors, Neurotensin; D017981:Receptors, Neurotransmitter; D018005:Receptors, Vasoactive Intestinal Peptide; D014660:Vasoactive Intestinal Peptide; D009496:Neurotensin; D000242:Cyclic AMP; D011188:Potassium; D002118:Calcium