Neuropeptide Y-induced contraction and its desensitization through the neuropeptide Y receptor subtype in several rat veins

Exogenous neuropeptide Y produced marked contractions in rat isolated common jugular, brachial, and caudal veins, while it produced little or no contractions in common carotid, brachial, and caudal arteries. Neuropeptide Y (30 nM) produced larger contractions in these veins than did phenylephrine (1 muM), with maximal contractions through the neuropeptide Y receptor and the alpha(1)-adrenoceptor, respectively. In contrast, neuropeptide Y (30 nM) produced smaller contractions than did phenylephrine (1 muM) in the arteries. Pre-treatment with neuropeptide Y (30 nM) showed remarkable desensitization to neuropeptide Y (30 nM). This desensitization lasted for 1 h in the caudal vein or for 2 h in the common carotid and brachial veins. The neuropeptide Y-induced contraction and its desensitization probably occurred through the neuropeptide Y receptor subtype Y-1, because only the neuropeptide Y receptor subtype Y-1 was detected in the smooth muscle by the reverse transcriptase-polymerase chain reaction.