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

• 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.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Farmakologi och toxikologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Pharmacology and Toxicology (hsv//eng)

Nyckelord

Amino Acid Sequence

Animals

Electric Stimulation

In Vitro Techniques

Male

Molecular Sequence Data

Muscle Contraction/drug effects

Muscle, Smooth/drug effects

Neuropeptide Y/pharmacology

Peptide Fragments/pharmacology

Peptide YY

Peptides/pharmacology

Rats

Rats, Inbred Strains

Swine

Vas Deferens/drug effects

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)