Extra-pituitary action of luteinizing hormone releasing hormone on intraocular pressure

Luteinizing hormone releasing hormone (LHRH) given intraventricularly caused a delayed, significant decrease of intraocular pressure (IOP) in adult female rabbits for a prolonged period, but only elevated plasma gonadotropins for a few hrs. Intravenous injections of LHRH caused a similar elevation of plasma gonadotropins without any effect on IOP. It indicates that LHRH initiates a mechanism in the central nervous system to decrease IOP, which is unrelated to the conventional LHRH-gonadotropin axis.