Ontogeny of adenosine deaminase in developing trophoblast and decidual cells of rat and hamster

The enzyme adenosine deaminase (ADA) is expressed at high level in the tiss ue of foeto-maternal interface during early pregnancy, As the main constitu ents of this interface are trophoblast (TR) and decidual cells (DC), the en zyme was estimated in isolated TR and DC to determine the extent of contrib ution by the respective cells, The enzyme level was estimated in cytosolic fraction, cell lysate and in conditioned media of these cells in rat and ha mster. In both species the concentration of ADA was found to be markedly hi gh in cytosolic fraction over to the cell lysate and the conditioned media in both TR and DC. Species-wise, it was higher in hamster. Cell-wise, the e nzyme activity was significantly higher in TR than DC in rat but equal in h amster. In the conditioned medium, also, the enzyme activity was higher in TR in both species. The inference drawn from the results are: 1) the maximu m enzyme activity in cytosolic fraction of TR and DC of both species clearl y indicates equal involvement of the cells that constitute foeto-maternal u nit, 2) the enhanced level of enzyme in TR and DC of hamster over to those of rat is possibly due to the higher proliferative activity in the cells of this species because of shorter gestation (16-17 days in hamster and 22-23 days in rats). (C) 2000 Harcourt Publishers Ltd.