The relationship between the daily pattern of food consumption and the proliferation rate of the oesophagus, stomach, forestomach, small intestine and colon of Ha/ICR @entity19 was examined. Proliferative activity was determined by @entity665 incorporation on a wet weight tissue basis, along with selective counting of labelled nuclei. Under conditions of ad libitum feeding with a 12 hr light cycle (lights on at 0600) @entity19 eat most of their food during the dark period. A distinct circadian rhythm was observed in the oesophagus, stomach, forestomach and colon with the peak of @entity665 incorporation between 0400 and 0600 and the nadir between 1600 and 1800. Although a circadian fluctuation was observed in the small intestine, its amplitude was much less than in other areas. This rhythmic change in proliferation rate could be phase shifted by allowing the @entity19 to feed only between 0800 and 1600 for 14 days. Under these conditions the peak in proliferative activity occurred between 1800 and 2000. Fasting reduced the daily level of proliferative activity in all of the digestive tract sites studied, and for all areas except the oesophagus greatly reduced or eliminated the circadian fluctuation. The forestomach and colon were the most influenced by fasting with 24 hr @entity665 incorporation reduced to 30-40% of the control value. Refeeding following a 48 hr fast produced a rapid increase in proliferative activity peaking at levels well above the control value at 16 hr after the onset of refeeding. The major exception to this was the small intestine which slowly returned to the control value during the first 24 hr. Partial refeeding produced a diminished refeeding response. Once the normal pattern of food consumption was re-established following refeeding the normal proliferative fluctuations were again observed.

Digestive tract cell proliferation and food consumption patterns of Ha/ICR XXXX .

@entity19 :: ('10090', 'Species') :: ['mice'] @entity665 :: ('CHEBI:53526', 'Chemical') :: ['[3H]TdR']
@entity19 :: (10090,Species) :: ['mice']
