CLASSIFICATION OF HUMAN SCLERAL SPUR CELLS IN MONOLAYER-CULTURE

Aqueous humor outflow in primate eyes can be facilitated by ciliary mu scle contraction, thereby widening fluid pathways through the trabecul ar meshwork, Recently in the scleral spur smooth muscle (sm) alpha-act in positive myofibroblast-like cells have been described which are in contact with the elastic fiber system of both the spur and trabecular meshwork, In the vicinity of these tells nerve terminals have been des cribed, It is speculated that contraction of scleral spur cells can fa cilitate aqueous humor outflow; too, To provide a tool for further phy siological and pharmacological studies monolayer cell cultures of huma n scleral spur have been established and characterized, For this purpo se, cells derived from scleral spur, outer and inner trabecular meshwo rk and ciliary muscle tips from 7 donor eyes (43-87 years-old respecti vely, obtained 3-7 h post mortem) were grown in tissue culture medium and the different monolayer cells classified by their growth character istics, and by immunohistochemical staining for vimentin, alpha-sm-act in, desmin, and alpha B-crystallin, respectively, In addition, the pre sence of alpha B-crystallin mRNA and desmin mRNA was verified using th e polymerase chain reaction (PCR)-method. We were able to characterize and distinguish human scleral spur cells from adjacent ciliary muscle and trabecular meshwork cells. Scleral spur cells (SPC) grew slower t han ciliary muscle cells (CMC) but much faster than trabecular meshwor k cells (TMC), All cells showed the same staining characteristics in v itro as they did in vivo. Scleral spur cells stained for vimentin and alpha-sm-actin, but not for desmin and alpha B-crystallin, The corresp onding mRNAs of the latter two proteins could not be detected by PCR i n the spur cells, Cells grew out from all donor eyes so that they actu ally provide a tool for further experimental studies.