Effects of various neuropeptide Y/peptide YY fragments on electrically-evoked contractions of the rat vas deferens

Br J Pharmacol. 1990 May;100(1):190-2. doi: 10.1111/j.1476-5381.1990.tb12075.x.

Abstract

1. The effects of various neuropeptide Y (NPY) and peptide YY (PYY) fragments on electrically-evoked twitches in the rat isolated vas deferens were studied and compared with the effects of full length NPY and PYY. The aim was to identify the shortest NPY/PYY fragments that are capable of suppressing the contractions. 2. NPY (1-36) and C-terminal fragments of NPY (from 11-36 to 22-36) suppressed the electrically-evoked twitches in a concentration-dependent manner. On the whole there seemed to be a gradual lowering of the pIC50 values with progressive shortening of the NPY fragments (except for fragments 16-36 and 22-36 that had rather high pIC50 values). NPY 23-36, 24-36 and 25-36 suppressed the twitches at high concentrations (3 microM). NPY 26-36 was without effect as were C-terminal carboxy-deaminated NPY and glycine extended NPY (NPY-Gly-Lys-Arg). 3. PYY (1-36) and C-terminal fragments of PYY (from 11-36 to 23-36) suppressed the electrically-evoked twitches in a concentration-dependent manner. PYY 1-36 was more potent than any of the fragments. There was a tendency for shorter fragments to have lower pIC50 values. PYY 24-36 and 25-36 suppressed the twitches at high concentrations (3 microM). PYY 26-36 was without effect. 4. The findings suggest that the 12 C-terminal amino acid residues of NPY and PYY are the minimum length required to activate the Y2-receptor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Electric Stimulation
  • In Vitro Techniques
  • Male
  • Molecular Sequence Data
  • Muscle Contraction / drug effects
  • Muscle, Smooth / drug effects*
  • Muscle, Smooth / physiology
  • Neuropeptide Y / pharmacology*
  • Peptide Fragments / pharmacology
  • Peptide YY
  • Peptides / pharmacology*
  • Rats
  • Rats, Inbred Strains
  • Swine
  • Vas Deferens / drug effects
  • Vas Deferens / physiology

Substances

  • Neuropeptide Y
  • Peptide Fragments
  • Peptides
  • Peptide YY