Beta-adrenergic mechanisms affect cell division and differentiation in cultured chick lens epithelial cells

Primary cultures of chick lens annular pad (CLAP) cells were exposed to beta-adrenergic drugs and lipid soluble cAMP analogues. In dose-dependent manners, these agents inhibited re-entry into the cell cycle when these normally post-mitotic cells were cultured in the presence of serum. The inhibition of cell division was evidenced by a lack of DNA accumulation and greatly reduced tritiated thymidine incorporation into DNA. Treated cells were also largely inhibited from spreading onto the substrate. Instead, the epithelial monolayers originally placed into culture formed nearly spherical aggregates. Treated cultures continued to synthesize crystallins and exhibited increased levels of a 49-kDa cytoskeletal protein which accumulates in fiber cells. These results indicate that beta-adrenergic mechanisms may be involved in regulating cell division and terminal differentiation of lens fiber cells.