Comparison of the gastric exocrine inhibitory activities and plasma kinetics of somatostatin-28 and somatostatin-14 in cats

Barry H. Hirst, J. Michael Conlon, David H. Coy, Joy Holland, Bernard Shaw

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)

Abstract

The gastric exocrine inhibitory activities of somatostatin-28 (SS-28) and somatostatin-14 (SS-14) were determined in conscious cats prepared with gastric fistulae. Gastric acid and pepsin secretions were stimulated with pentagastrin. Expressed in terms of exogenous doses, SS-14 (ID50: 1.49 nmol · kg-1 · h-1) was 3.4 times more potent than SS-28 (ID50: 5.12 nmol · kg-1 · h-1) as an inhibitor of gastric acid secretion. Similarly SS-14 (ID50: 0.25 nmol · kg-1 · h-1) was 3.8 times more potent than SS-28 (ID50: 0.96 nmol · kg-1 · h-1) as an inhibitor of pepsin secretion. Expressed in terms of circulating plasma concentration measured by radioimmunoassay, SS-14 (ID50: H+, 232 and pepsin 73 pM) was 8-9 times more potent than SS-28 (ID50: H+, 2112 and pepsin, 611 pM) as an inhibitor of gastric exocrine secretions. The plasma immunoreactive half-life of SS-28 (6.1 min) was double that for SS-14 (2.4 min) possibly due to a slower theoretical metabolic clearance rate of the larger peptide (30 and 87 ml · kg-1 · min-1, respectively). Both peptides had similar apparent distribution volumes (SS-14, 306 and SS-28, 263 ml · kg-1). As judged by gel chromatography of plasma samples, there was no evidence for the conversion of SS-28 to SS-14 in vivo. The reduced activity of SS-28, compared with SS-14, against gastric exocrine secretions contrasts with its more potent effects in the pituitary and pancreas.

Original languageEnglish
Pages (from-to)227-237
Number of pages11
JournalRegulatory Peptides
Volume4
Issue number4
DOIs
Publication statusPublished - Sep 1982
Externally publishedYes

Keywords

  • gastric acid secretion
  • pentagastrin
  • pepsin secretion
  • prosomatostatin

ASJC Scopus subject areas

  • Biochemistry
  • Physiology
  • Endocrinology
  • Clinical Biochemistry
  • Cellular and Molecular Neuroscience

Fingerprint

Dive into the research topics of 'Comparison of the gastric exocrine inhibitory activities and plasma kinetics of somatostatin-28 and somatostatin-14 in cats'. Together they form a unique fingerprint.

Cite this