Effect of cAMP- and cGMP-related drugs on porcine cultured ciliary muscle.

We studied in this work the compounds which affect the contraction of ciliary muscle and are potential ocular hypotensive drugs, and second messengers produced by the compounds. Using second-passaged porcine cultured ciliary muscle, single cell contraction was used for assay. Cell contraction by carbachol was affected by isobutyl methylxanthine, forskolin, dibutyryl cGMP and sodium nitroprusside (SNP). Forskolin increased intracellular cAMP while SNP stimulated cGMP formation. The results indicate that these cAMP- or cGMP-related compounds could affect the contraction of ciliary muscle like prostaglandins and could therefore have a potential to reduce intraocular pressure.