THE EFFECTS OF EXCITEMENT, OF EPINEPHRINE AND OF SYMPATHECTOMY ON THE MITOTIC ACTIVITY OF THE CORNEAL EPITHELIUM IN RATS

Abstract

Excitement or annoyance of rats, particularly by painful stimuli, diminishes the mitotic rate in their corneal epithelium. The decrease of mitotic rate caused by excitement is an andrenergic response and can be simulated by local or systemic application of epinephrine. Both ergotamin and nicotin diminish the mitosis inhibition following excitement. The effect of epinephrine is not due to a decrease in tissue temp. or to local circulatory disturbances. Removal of the superior cervical ganglion leads to a decreased mitotic rate in the rats'' corneal epithelium after a lag period of about 20 hrs. It is suggested that this effect is attributable to the absence of some factor other than sympathin which regulates mitotic activity in this tissue under physiological conditions, and that this manifestation of denervation may be related to that of sensi-tization.