The DC-ERG as a highly sensitive measure of effects of prostaglandins.

A few microliters of a prostaglandin preparation (PGE2 or PGF2 alpha) were injected via the ora serrata into the posterior vitreous of one of the eyes in albino rabbits. The fellow eye received an equal volume of saline intravitreally and served as control. The DC electroretinogram (ERG) and the standing potential of the eye (SP) were recorded directly with corneal contact lenses, very stable calomel electrodes, and under very constant anesthesia. The b- and c-wave amplitudes increased in response to 0.1 and 1.0 microgram of PGE2 and PGF2 alpha, respectively. At medium doses there was an increase in the b- and c-wave amplitudes followed by a long-lasting reduction. At very high, nonphysiological doses of PGE2, b- and c-wave amplitudes decreased as compared with the control eye. Prostaglandins modify inflammatory reactions, influence ion transport across membranes, modulate synaptic transmission, and regulate blood flow to various organs. Effects of extremely low doses on the retina and pigment epithelium might indicate a transmitter-like nature of prostaglandins. The present experimental model might be of use in studies of inflammatory eye disease, prostaglandin inhibitors, and characteristics of the pigment epithelial membranes.