Effect of vasoactive intestinal peptide on serotonin release in the suprachiasmatic area of the rat. Modulation by oestradiol |
| |
Authors: | Micheline Hery Maxime Faudon Francis Hery |
| |
Affiliation: | 1. Unité de Rechereches Neurobiologiques, INSERM-U.6, 280 Bd Sainte-Marguerite, 13009 Marseille, France;2. CNRS-GR.45, 280 Bd, Sainte-Marguerite, 13009 Marseille, France |
| |
Abstract: | The effect of vasoactive intestinal peptide (VIP) on spontaneous and induced release of newly synthesized 5-hydroxytryptamine (5-HT) was studied in the suprachiasmatic area (SCA) using a superfusion system. To test the possible modualtion by E2 on the interaction VIP-5-HT, the experiments were conducted on male, ovariectomized (OVX) and ovariectomized oestradiol implanted rats (OVX-E2). VIP (10?7 M) infused for 15 min caused an increase of 5-HT release from SCA of male and OVX. The positive effect of VIP on 5-HT release results partially from an inhibition of the reuptake of 5-HT: in male and OVX SCA, VIP inhibited the 3H-5-HT uptake by 40 to 50%. The infusion of VIP before a pulse of K+ (10-20-30-56 mM) leads to a potentialisation of the evoked release suggesting that VIP sensitized the presynaptic membrane to the process linking depolarization and release. When SCA taken from OVX-E2 were exposed to VIP, 5-HT uptake and consequently 5-HT release were unchanged. The present results suggest that the metabolism of 5-HT in the SCA is influenced by VIP and that this regulation may be modulated by E2. This interaction between E2, VIP and 5-HT at the SCA level may be involved in the regulation of phasic LH and prolactin surge. |
| |
Keywords: | Suprachiasmatic nucleus VIP 5-HT Oestradiol |
本文献已被 ScienceDirect 等数据库收录! |
|