[Effect of T-lymphocytes on the cellular proliferation of the salivary glands in rats and mice exposed to isoproterenol].

It has been shown that in the course of isoproterenol induction of cell proliferation of rat and mouse salivary glands, there takes place formation of T lymphocytes that stimulate and inhibit proliferation of the gland cells. In the absence of T lymphocytes isoproterenol does not induce cell proliferation. It has been demonstrated in mice that lymphocytes that stimulate cell proliferation of the salivary glands belong to Ly 1+ T lymphocytes whereas those inhibiting proliferation to Ly 2+ T lymphocytes. The former ones are formed and proliferate before commencement of glandular cell proliferation, and the latter ones concurrently with the development of cell proliferation of the salivary glands. The mechanisms described may point to the existence of a special system of T lymphocytes, that is not identical to the immune system, with this special system playing a definite role in the maintenance of the proliferative homeostasis of host tissues.