Incorporation of 3H-befunolol (beta-blocking agent) into melanin granules of ocular tissues in the pigmented rabbits. I. Light microscopic radioautography.

3H-befunolol was administered intravenously to pigmented rabbits. Thirty minutes after the administration, the iris, ciliary body and retina were fixed, embedded and processed for light microscopic radioautography. Radioautographical silver grains were observed over the pigment granules of the iris, ciliary body, choroid and retina. From these results it is concluded that 3H-befunolol is incorporated into the pigment granules of these cells. The mechanism of incorporation is discussed.