Immuno-enhancement and-inhibition of GH-releasing factor by site-directed anti peptide antibodies in vivo and in vitro

It is now well established that specific antibodies and binding proteins can potentiate rather than inhibit hor-mone activity. In order to investigate this phenomenon further, the current study was undertaken using a hor-mone with a characterised structure, in terms of receptor binding, and for which activity has already been manipu-lated in specific ways (prolongation of half-life, increased receptor affinity) using synthetic hormone analogues. GH\x=req-\ releasing factor (GRF) is a 40 or 44 residue peptide and is, together with somatostatin, responsible for the regulation of GH secretion. The effects of site-directed anti peptide antibodies were determined on the activity of GRF in vivo and in vitro as GH release. The peptide regions of GRF were: 1\p=n-\14(part of putative receptor-binding region) an