Studies on mitotic-activity control in white mice. I. Diurnal relation between the blood-sugar level and the mitotic activity in the corneal epithelium
Dziekanowska, Danuta; Nowak, A.
Acta Physiol Polon 12(1): 137-143
The investigations were designed to determine the relation between the diurnal changes as of mitotic activity in the corneal epithelium and blood sugar level in male white mice. The animals, 6 months old, were decapitated in groups of five every two hours (from 02 to 24 o'clock. Blood sugar level was determined after the method of Hagedorn-Jensen, and mitotic activity in cornea preparations stained in toto with iron haematoxylin after Heidenhain. The number of mitosis was highest in the morning (peak at 6 a.m.) and lowest in the evening (6[long dash]8 p. m.), which accords with the results of Carleton and Vasama and Vasam. The difference between our results and those of Bullough, who recorded two peaks and two lows of mitotic activity, are likely to be attributable to differences in feeding time. By comparing mitotic activity with blood-sugar level, changes of the two were found to be roughly inversely proportionate. The diurnal rhythm of the mitotic activity probably depends not so much on the time of the day as on the animal's motor activity, for in our experiments it was least when the animals were most active (after waking and after feeding), and highest during sleep.