apid advances in the field of peptide chemistry and gene technology have resulted in a burst of determinations about the molecular structures not only of regulatory peptides such as galanins (Gal) of various species but also of their precursors and receptors. Based on information about mature peptides and precursor structures, Gal-related peptides and other peptides with related amino acid sequences were synthesized. Certain specifically designed synthetic peptides have enabled the investigation of such questions as the molecular basis of receptor binding and the active role of peptides. 1 Synthetic replicates of Gal of various species and its precursor-related peptides provide us with important immunogens for producing region-specific antibodies. Specific antibodies against Gal or its precursor-related peptides demonstrate well the posttranslational biosynthetic processing in cells and identify steps in the metabolite pathway of the regulatory peptide in tissues and tissue fluids. 2,3 Exogenous administration of Gal has been shown to contract smooth muscle preparations 3-6 and to inhibit neurally induced smooth muscle contractility. Gal stimulates the release of growth hormone (GH), 7,8 prolactin, 9 and luteinizing hormone either from dispersed pituitary cells or at the hypothalamic level modulating dopamine, vasoactive intestinal polypeptide, (VIP), somatostatin, opioid, and GnRH release into the portal circulation 10-13 and inhibits insulin release. [14][15][16][17][18][19][20][21][22][23] In this review, we describe structure-function studies of the endocrine and gastrointestinal action of Gal. PEPTIDES AND ANTISERAPeptides. All peptides used in the study were synthesized by solid phase methodology with BOC-or Fmoc-strategy using an automated peptide synthesizer (model 430A, Applied Biosystems, or model 9050, Perseptive, USA). The crude peptide was purified by reverse-phase HPLC on a column of YMC-Pack D-ODS-5 (2.0 × 25.0 cm) using 0.01 N HCl/CH 3 CN. Purity of the peptides was assessed by analytic HPLC on a column of YMC

Bifemelane hydrochloride (BFM -HC1) and indeloxazine hydrochloride (IND-HC1) were found to enhance significantly VIP release from human neuroblastoma NB-OK»1. BFMHCl enhanced VIP release from the cells dose-dependently at concentrations of 10-5-10'5" M during 24 h. IND -HC1 at 10"?' M concentration also increased VIP release, but to a lesser extent. VIP content in the cells increased significantly when the cells were incubated with 10'5-10"" M IND -HC1 for 24 h, but no dose-dependence of the effect was observed. Scatchard plot analysis revealed the existence of at least two classes of specific IND-binding sites: one having Kd 1.3 ;.¢M and Bmax 2.5 >< 10"2 fmol/cell and the other having Kd 465 /.tM and Bmax 15 fmol/cell. BFM -HC1 also shared the IND-binding sites with a Ki value of 67 nM. The binding component in solubilized membrane preparation of the NB-OK-1 cells was found to have a molecular mass of 65 kDa. Although further investigation is required to demonstrate that the binding of these drugs to such sites induce directly the release of VIP, the results encouraged us to use the present system to explore the mechanism of VIP release by these drugs.