VIP modulation of cultured glial cells of the rat retina

Abstract
Cultured retinal glial cells from the rat are responsive to modulation by vasoactive intestinal peptide (VIP). VIP (IX 10−6M) elevated the intracellular cyclic AMP concentration from the basal level of (4.4–11.1) p mole/mg protein to (354–440) p mole/mg protein in threi minutes at 25oC. The half-maximal concentration is 4.8X10−8M, which is similar to that observed in the cultured retinal glial cells from the chick embryo.