title: Identification of nonsulfated cholecystokinin-58 in canine intestinal extracts and its biological properties.
abstract: Nonsulfated CCK(58) [CCK(58)(ns)] has not been considered to be of biological importance because CCK(58)(ns) binds poorly to the CCK(A) receptor and has only been identified once in intestinal extracts. In this work, a radioimmunoassay specific for the COOH-terminal region of gastrin and CCK (antibody 5135) was used to monitor the purification of CCK molecular forms from canine intestinal extracts. A minor immunoreactive peak was associated with a major absorbance peak during an ion-exchange, HPLC step. Characterization of this minor immunoreactive peak demonstrated that it was CCK(58)(ns). CCK(58)(ns) is 14% as immunoreactive as sulfated CCK(8) [CCK(8)(s)]. Amino acid analysis demonstrated that CCK(58)(ns) was present at 50% the amount of CCK(58)(s). In addition, we found that CCK(58)(ns) does not potently displace an (125)I-labeled CCK(10) analog from the CCK(A) receptor in mouse pancreatic membranes and does not stimulate amylase release from isolated pancreatic acini, or stimulate pancreatic secretion in an anesthetized rat model. By contrast, CCK(58)(ns) does bind to CCK(B) receptors and stimulates gastric acid secretion via this receptor. The presence of CCK(58)(ns) and its ability to selectively stimulate the CCK(B) receptor without stimulation of the CCK(A) receptor suggest that CCK(58)(ns) may have unique physiological properties, especially tissues where the nonsulfated peptide can act as a paracrine or neurocrine agent.
authors.affiliation: CURE: Digestive Diseases Research Center, Bldg. 115, Rm. 115, VA Greater Los Angeles Health Care, Los Angeles, CA 90073, USA. jreeve@ucla.edu
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Reeve
authors.forename: Rodger A
authors.initials: RA
authors.lastname: Liddle
authors.forename: Douglas C
authors.initials: DC
authors.lastname: McVey
authors.forename: Steven R
authors.initials: SR
authors.lastname: Vigna
authors.forename: Travis E
authors.initials: TE
authors.lastname: Solomon
authors.forename: David A
authors.initials: DA
authors.lastname: Keire
authors.forename: Grace
authors.initials: G
authors.lastname: Rosenquist
authors.forename: John E
authors.initials: JE
authors.lastname: Shively
authors.forename: Terry D
authors.initials: TD
authors.lastname: Lee
authors.forename: Peter
authors.initials: P
authors.lastname: Chew
authors.forename: Gary M
authors.initials: GM
authors.lastname: Green
authors.forename: Tamer
authors.initials: T
authors.lastname: Coskun
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000681:Amylases / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism; D002766:Cholecystokinin / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification* / Q000494:pharmacology / Q000502:physiology*; D004285:Dogs; D005744:Gastric Acid / Q000378:metabolism; D066298:In Vitro Techniques; D007422:Intestines / Q000737:chemistry*; D008297:Male; D051379:Mice; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D043886:Receptor, Cholecystokinin A / Q000378:metabolism; D043887:Receptor, Cholecystokinin B / Q000378:metabolism; D012844:Sincalide / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: C090019:8-sulfocholecystokinin octapeptide; D000596:Amino Acids; D043886:Receptor, Cholecystokinin A; D043887:Receptor, Cholecystokinin B; C038823:cholecystokinin 58; D002766:Cholecystokinin; D000681:Amylases; D012844:Sincalide