Elevated retinal cGMP is not associated with elevated circulating cGMP levels in a canine model of retinitis pigmentosa.

Purpose: To investigate whether raised levels of retinal cyclic guanosine monophosphate (cGMP) was reflected in plasma levels in PDE6A-/- dogs.

Materials And Methods: Retina was collected from 2-month-old wildtype dogs (PDE6A+/+, N = 6), heterozygous dogs (PDE6A+/-, N = 4) and affected dogs (PDE6A-/-, N = 3) and plasma was collected from 2-month-old wildtype dogs (PDE6A+/+, N = 5), heterozygous dogs (PDE6A+/-, N = 5) and affected dogs (PDE6A-/-, N = 5). Retina and plasma samples were measured by ELISA.