In vivo effects of Sn-1,2-dioctanoylglycerol, TPA and A23187 on hamster cheek pouch epithelium.

Cheek pouches of male Syrian golden hamsters were topically treated with a single dose of TPA (.5 microgram), calcium ionophore A23187 (75 micrograms) or Sn-1,2-dioctanoylglycerol (DiC8) (500 micrograms) dissolved in 0.25 ml acetone. Acetone-treated animals served as controls. After 48 h the mitotic index for the control group was 1.1 +/- 0.1 per 1 mm of the basement membrane length. All the test congeners exhibited higher mitotic indices than controls: TPA (4.8 +/- 0.4), A23187 (3.9 +/- 0.3), DiC8 (2.1 +/- 0.2). All groups exhibited an increase in the epithelial thickness manifested by cellular hyperplasia. The treatment of the pouches with the anti-inflammatory agent fluocinolone acetonide inhibited the mitogenic and hyperplasiogenic affects on the epithelium induced by the various test chemicals. These studies indicate a possible role of calcium-phospholipid dependent protein kinase (protein kinase C) in the mediation of oral epithelial cell proliferation.