Opossum colonic mucosa contains uroguanylin and guanylin peptides

F. Kent Hamra, William J. Krause, Sammy L. Eber, Ronald H. Freeman, Christine E. Smith, Mark G. Currie, Leonard R. Forte

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Uroguanylin and guanylin are structurally related peptides that activate an intestinal form of membrane guanylate cyclase (GC-C). Guanylin was isolated from the intestine, but uroguanylin was isolated from urine, thus a tissue source for uroguanylin was sought. In these experiments, uroguanylin and guanylin were separated and purified independently from colonic mucosa and urine of opossums. Colonic, urinary, and synthetic forms of uroguanylin had an isoelectric point of ~3.0, eluted from C18 reverse-phase high- performance liquid chromatography (RP-HPLC) columns at 8-9% acetonitrile, elicited greater guanosine 3',5'-cyclic monophosphate (cGMP) responses in T84 cells at pH 5.5 than pH 8, and were not cleaved and inactivated by pretreatment with chymotrypsin. In contrast, colonic, urinary, and synthetic guanylin had an isoelectric point of ~6.0, eluted at 15-16% acetonitrile on C18 RP-HPLC columns, stimulated greater cGMP responses in T84 cells at pH 8 than pH 5.5, and were inactivated by chymotrypsin, which hydrolyzed the Phe- Ala or Tyr-Ala bonds within guanylin. Uroguanylin joins guanylin as an intestinal peptide that may participate in an intrinsic pathway for cGMP- mediated regulation of intestinal salt and water transport. Moreover, uroguanylin and guanylin in urine may be derived from the intestinal mucosa, thus implicating these peptides in an endocrine mechanism linking the intestine with the kidney.

Original languageEnglish (US)
Pages (from-to)G708-G716
JournalAmerican Journal of Physiology - Gastrointestinal and Liver Physiology
Issue number4 33-4
StatePublished - 1996


  • T84 cells
  • guanosine 3',5'-cyclic monophosphate
  • guanylate cyclase
  • urine

ASJC Scopus subject areas

  • Physiology
  • Hepatology
  • Gastroenterology
  • Physiology (medical)


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