Inhibition by brimonidine of forskolin-induced nitric oxidesynthase expression in human ciliary bodies in vitro

[摘要] Purpose: To investigate the mRNA and protein expression of nitricoxide synthase (NOS) in human ciliary bodies in vitro. The effect of theadenylcyclase activator forskolin and/or the α2-adrenergicagonist brimonidine (an ocular hypotensive agent that inhibits aqueoushumor formation) on NOS mRNA or protein expression was also studied.Methods: Frozen human ciliary bodies obtained from local eye bankwere thawed and incubated with 0.1 mM forskolin for 24 h in the absenceor in the presence of 100 μM brimonidine. The mRNA and proteinexpression of three NOS isoforms (neuronal NOS or nNOS, inducible NOS oriNOS, endothelial NOS or eNOS) were assessed by reversetranscription-polymerase chain reaction (RT-PCR) and Western blotanalysis, respectively.Results: mRNA and protein expression of three NOS isoforms weredetected in human ciliary bodies. Forskolin significantly up-regulatedthe mRNA and protein expression of nNOS, but not that of iNOS or ofeNOS. In the presence of brimonidine, the forskolin-inducedup-regulation of nNOS mRNA or protein expression was significantlyinhibited.Conclusions: In human ciliary body (where aqueous humor isproduced), brimonidine inhibits the up-regulation of nNOS expressioninduced by forskolin.

[学科分类] 生物化学/生物物理