HYALOCYTE-LIKE CELLS ARE MORE NUMEROUS IN THE POSTERIOR CHAMBER THAN THEY ARE IN THE VITREOUS OF THE RABBIT EYE

The distribution and concentration of free cells inside the eye chambe rs of rabbits were investigated using semi-quantitative analysis of hi stological paraffin sections. Studies using light (methacrylate sectio ns) as well as transmission and scanning electron microscopy were unde rtaken for the morphological characterization of the free cells. Immun ocytochemistry and autoradiography were employed in an attempt to find out their nature and their origin, respectively. It was observed that cells morphologically similar to the vitreous hyalocytes were more nu merous inside the posterior chamber than were the hyalocytes in the co rtical vitreous. Neither the hyalocytes nor the posterior-chamber cell s reacted with an antibody to rabbit macrophages. The finding of label ed free cells after an intravitreal injection of H-3-thymidine indicat es that these cells can renew themselves and that their number does no t depend exclusively on monocytes migrating from the blood stream to t he eye chambers, as is believed to occur. In conclusion, hyalocytes or hyalocyte-like cells are more concentrated in the posterior chamber t han they are in the vitreous. Both the hyalocytes and the posterior-ch amber cells could not be characterized as fully developed macrophages. (C) 1998 Academic Press.