Melanocyte Dendrites Research Articles

The effect of various hormones on the uptake and distribution of an organic mercurial compound in the guinea pig eye

With the exception of the aqueous humor all ocular tissue analyzed from guinea pigs dosed for 5 wk by instillation of hydrargaphen into the conjunctival sac showed a significant ( p = 0.05) uptake of mercury. The hormones melatonin, ACTH, and MSH produced the following results. With melatonin at 2.3 × 10 6 U/kg daily a significant decrease in mercury levels was found in the cornea and lens; with ACTH at 0.4 U/kg daily, a significant increase in mercury level was found in the retina; and with MSH at 680 U/kg daily there was a significant increase in mercury deposition in the aqueous humor, lens, and retina. Compared to the similar tissue from nondosed control animals, the level of mercury in the aqueous humor of animals treated with hydrargaphen and MSH was highly significant, indicating that the effects of MSH were probably brought about by increased metastatic deposition of mercury in the eye. Morphological investigations showed that veins and venules of the uveal tract are bordered by melanocyte dendrites. It is suggested that MSH acts on the melanocytes of this tissue, causing granule dispersion into the dendrites, with the consequent increase in pressure on the venule walls assisting increased passage of large molecules into the eye.