Inhibition of mouse parenchymal cells proliferation by mosquito larvae extract.

As it is known, some cell populations of mosquito Aedes aegypti larvae do not proliferate. This fact suggests the existence of some mitosis inhibiting factor. We have assayed the effect of mosquito larvae crude extract on 85 C3HS young male mice (25 +/- 1 days old) and the effect of the dialyzed fraction of the same extract on 47 partially hepatectomized C3HS adult male mice. The injection was performed at 16:00 hour (before the raising of the DNAS curve) and the controls were made at 08:00/16, 12:00/20 and 16:00/24 (Time of Day/Time Post Injection). Colchicine arrested metaphases of nephrocytes, hepatocytes, sialocytes (submaxillary glands) and enterocytes were controlled. The mitotic rate was significantly inhibited in hepatocytes, sialocytes and enterocytes in young growing mice, and in hepatocytes in partially hepatectomized adult mice. We conclude that TGF-beta, actually found in insects, or alternatively some other known or unknown factor, could be responsible for the results observed in the present experiments.