Isoproterenol and G2 acinar cells in the developing rat parotid gland.

In the present study, premitotic period (G2)-delayed or blocked acinar cells were identified in the parotid gland of the neonatal rat. The noncycling G2 cells retain the potential to divide and respond to administration of the sympathomimetic amine, isoproterenol (IPR). The effects of IPR on suckling and weaned rats were compared. Both groups showed the presence of G2-acinar cells with a possible age-related change occurring after weaning.