Actin filaments in trabecular endothelial cells in eyes of the vervet monkey. (Cercopithecus aethiops).

An electron microscopic study was performed on the trabecular meshwork of two monkeys (cercopithecus aethiops). Specimens from one animal revealed numerous cytoplasmic filaments of 45-65 A thickness in endothelial cells both on the trabeculae in the wall of Schlemm's canal after conventional glutaraldehyde and osmium fixation. Using a histochemical technique it was shown in specimens from the other animal that these filaments consist of actin material. This evidence of intracellular actin filaments in the trabecular endothelium indicates that these cells have contractile properties, and the possible significance of this finding for the regulation of outflow facility of aqueous humour is suggested.