Immunoactive atrial natriuretic peptide in the rat eye: molecular forms in anterior uvea and retina

Acid extracts of rat anterior uvea and retina contain immunoactive atrial natriuretic peptide. Gel filtration chromatography demonstrates that the major forms of the uveal and retinal material have approximate molecular weights of 2400 and 1750 daltons respectively, similar in size to the hypothalamic form of the peptide but clearly distinguishable from the larger, cardiac form. When further analyzed by RP-HPLC, the immunoactive material from both ocular tissues elutes at a position similar to atrial natriuretic peptide-28, again distinguishing the ocular and cardiac forms of immunoactive material. These results suggest potential roles for atrial natriuretic peptide both in ocular vegetative physiology and in retinal function.