Investigative Ophthalmology & Visual Science, Vol 24, 16-23, Copyright © 1983 by Association for Research in Vision and Ophthalmology

ARTICLES AND REPORTS

Retinomotor pigment migration in the teleost retinal pigment epithelium. II. Cyclic-3',5'-adenosine monophosphate induction of dark- adaptive movement in vitro

B Burnside and S Basinger

The retinal pigment epithelium (RPE) and photoreceptors of teleosts exhibit dramatic examples of cell motility (called retinomotor movements) in response to diurnal changes in lighting conditions. In darkness the pigment granules of the RPE migrate to the scleral base of the RPE cell and cone photoreceptors elongate. In the light these movements are reversed; pigment granules disperse into the long apical projections of the RPE cell and cones contract. It is reported here that treatments that elevate cytoplasmic cyclic AMP induce dark- adaptive movements (pigment aggregation and cone elongation) in light- adapted retinas cultured in the light. Treatments designed to elevate cGMP had no effect. In dose-response studies with the cAMP analog, dibutyryl cyclic AMP (dbcAMP), we found that the RPE pigment did not exhibit intermediate states of aggregation with increasing concentrations of dbcAMP but instead changed abruptly from the fully light-adapted to the fully dark-adapted retinomotor positions between 10 microM and 50 microM exogenous dbcAMP concentrations. Cones, on the other hand, elongated to intermediate extents in proportion to increasing dbcAMP concentration between 10 microM and 500 microM. These observations suggest that cytoplasmic cAMP plays a role in regulating retinomotor position in both RPE and cones.

This article has been cited by other articles:

				C King-Smith, P Chen, D Garcia, H Rey, and B Burnside Calcium-independent regulation of pigment granule aggregation and dispersion in teleost retinal pigment epithelial cells J. Cell Sci., January 1, 1996; 109(1): 33 - 43. [Abstract] [PDF]