Modulation of insulin-stimulated DNA synthesis by cholera toxin in bovine mammary fibroblasts

Yuh, I. S.; Park, C. K.; Han, J. Y.; Sheffield, L. G.

doi:1993.6.4.483

Article

Animal Breeding and Genetics

Asian-Australasian Journal of Animal Sciences 1993;6(4): 483-489.
https://doi.org/10.5713/ajas.1993.483 Published online December 1, 1993.

Modulation of insulin-stimulated DNA synthesis by cholera toxin in bovine mammary fibroblasts

I. S. Yuh, C. K. Park, J. Y. Han, L. G. Sheffield

Abstract

Bovine fibroblasts were cultured in Dulbecco`s Modified Eagle`s Medium and then treated with control, insulin (1, 1 關g/ml), cholera toxin (CT, 0.1-100 ng/ml) or CT (0.1-100 ng/ml) + 1 (1 關g/ml). cholera toxin, an activator of adenylate cyclase, significantly decreased insulin induced DNA synthesis (p<0.05). The modulation of DNA synthesis apparently involves events occurring in early stage of cell growth, at least between the first 4 and 8 hor of CT treatment. Insulin induced collagen as well as noncollagen synthesis in cell layer, however, these syntheses were reduced by addition of cholera toxin (p<0.05) but were not completely reduced. It is not clear whether the reduction of insulin-induced cell layer collagen or noncollagen proteins by CT is involved in the inhibitory effect on insulin-induced DNA synthesis. However, we could rule out the hypothesis that insulin-induced DNA synthesis is reduced by CT-induced cellular differentiation.

Keywords: Bovine Fibroblast; Cholera Toxin; Insulin; DNA Synthesis