Regulation of protein adenosine diphosphate ribosylation in bovine lens during aging.

Adenosine diphosphate-ribosyltransferase (ADPRT) and poly-ADP-ribose glycohydrolase (poly-ADPRG) activities were investigated in the different structures of bovine lenses. These activities and protein ADP ribosylation were detected only in the lens epithelium proliferative layer. The poly-ADPR glycohydrolase activity decreased, but the poly-ADPR polymerase activity increased during aging.

Modulation of adenylate cyclase activity in bovine lens epithelial cells.

Adenylate cyclase activity of bovine lens epithelial cells is activated by guanine nucleotides or fluoride. Additional activation to that of guanylylimidodiphosphate [Gpp(NH)p] was induced by isoproterenol. Insulin was found to inhibit adenylate cyclase activity.

Calcium-dependent regulation of adenylate cyclase and phosphodiesterase activities in bovine lens: involvement of lens calmodulin.

When calmodulin levels were determined in bovine lens layers at different ages, the values in the epithelial cell layer were strikingly higher than in the cortical layer and higher than in the nucleus. In the epithelial cell layer, except in very old animals, the calmodulin levels were maintained in adult animals. In the lens nucleus the extremely low level of calmodulin decreased during aging.

[PolyADP-ribosyl polymerase (adenosine diphosphate ribosyl transferase) in bovine crystalline lens; modulation of its activity during aging].

PolyADP-ribose polymerase activities were measured in bovine lens. Activities similar to those in brain were found in the epithelial cells; none activity was detected in the fiber cells. During aging ADP-ribosyl transferase activity of epithelial cells raised, the number of polyADP-ribose chains increased while the average chain length decreased.

[Gyrate atrophy of the choroid and retina in children. Apropos of 2 cases].

The authors report two familial cases of algerian children with a hyperornithinaemia and a gyrate atrophy. Blood ornithine was 10 to 20 above the normal, lysine and glutamic acid were slightly decreased. Urinary ornithine levels were very high.