Isoproterenol- Induced Changes in Cell Cycle Kinetics of Parotid Gland Acinar Cells in 8-Day-Old Rats

Abstract

Isoproterenol (IPR) was shown to alter some parameters of the parotid gland acinar cell cycle in 8-year-old rats. Although the deoxyribonucleic acid (DNA) synthetic period (S) was decreased and the pre-DNA synthetic (G₁) period was lengthened, there were no differences in the total cycle time. There was an increase in the 3H-thymidine labeling index from 35.7 to 50.8% combined with a decrease in the value of the mitotic index from 2.64 to 2.16% after IPR was administered. The results suggest that non cycling (G₀) cells may be involved in the normal differentiation of the parotid gland and that IPR alters the transition of acinar cells between the cycling and noncycling state.