Propagation of ciliary smooth muscle cells in vitro and effects of prostaglandin F2 alpha on calcium efflux.

The effect of prostaglandin F2 alpha (PGF2 alpha) on calcium efflux from ciliary smooth muscle cells was studied. Ciliary smooth muscle cells, cultured from human ciliary muscle explants, retained the morphologic and immunologic characteristics of smooth muscle cells. High concentrations (to 10(-6) mol/l) of PGF2 alpha were associated with a dose-dependent increase of calcium (45Ca) efflux, whereas at concentrations lower than 10(-8) mol/l there was little or no 45Ca efflux. Our in vitro data are inconsistent with the experimental hypothesis that PGF2 alpha at pharmacologic concentrations relaxes ciliary muscle with a consequent increase in uveoscleral outflow.