The effects of graded doses of a cholecystokinin-like peptide with and without secretin on pancreatic growth and synthesis of RNA and polyamines in rats

Scand J Gastroenterol. 1989 Oct;24(8):907-15. doi: 10.3109/00365528909089234.


The dose dependence of a cholecystokinin-like peptide (CCK-LP) on the trophic response in the rat pancreas was studied. Graded doses of Thr28Nle31CCK25-33 (0.02, 0.1, 0.5, 2.5, and 12.5 micrograms/kg/h) or saline were given as a continuous intravenous infusion to conscious and fed rats for 8 and 48 h. Secretin (5.0 micrograms/h) was given alone or combined with the three highest doses of CCK-LP for 48 h. CCK-LP showed a dose-dependent stimulating effect on pancreatic growth and synthesis of RNA and polyamines. The threshold dose ranged from 0.02 to 0.5 micrograms/kg/h and was lowest for stimulation of ornithine decarboxylase (ODC). The maximal effects on protein, RNA, and DNA contents were achieved with 2.5 micrograms/kg/h. These same variables markedly decreased with 12.5 micrograms/kg/h, whereas marked further increases were found for the activities of RNA polymerase, DNA polymerase, and thymidine kinase. This same dose of CCK-LP caused after 8 h of treatment a marked and transient increase in pancreatic weight, activity of ODC, and concentration of putrescine. When secretin was added to 0.5 and 2.5 micrograms/kg/h of CCK-LP, no additional effect (except for ODC) was found. When secretin was added to the highest dose of CCK-LP, the decreased contents of protein and RNA were significantly increased, and the markedly increased activities of RNA- and DNA-synthesizing enzymes were significantly decreased. The present study shows a clear dose-response relationship for the trophic effect of CCK-LP on the rat pancreas and indicates that the growth effect of a supramaximal dose includes components of regeneration secondary to damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biogenic Polyamines / biosynthesis*
  • Cholecystokinin / administration & dosage*
  • DNA / analysis
  • DNA-Directed RNA Polymerases / metabolism
  • Dose-Response Relationship, Drug
  • Infusions, Intravenous
  • Male
  • Organ Size / drug effects
  • Ornithine Decarboxylase / metabolism
  • Pancreas / drug effects*
  • Pancreas / growth & development
  • Pancreas / metabolism
  • Proteins / analysis
  • RNA / biosynthesis*
  • Rats
  • Rats, Inbred Strains
  • Secretin / administration & dosage*


  • Biogenic Polyamines
  • Proteins
  • Secretin
  • RNA
  • DNA
  • Cholecystokinin
  • DNA-Directed RNA Polymerases
  • Ornithine Decarboxylase