Circadian stage-dependent effects of insulin and glucagon on incorporation of (3H)thymidine into deoxyribonucleic acid in the esophagus, stomach, duodenum, jejunum, ileum, caecum, colon, rectum, and spleen of the adult female mouse.
Scheving-LA; Scheving-LE; Tsai-TH; Pauly-JE
Endocrinology 1982 Jul; 111(1):308-315
The effects of insulin and glucagon on DNA synthesis as noted by tritiated thymidine incorporation into the esophagus, glandular stomach, duodenum, jejunum, cecum, colon, rectum, and spleen were determined using 6 week old female BALB/Cann-mice on 12 hour light, 12 hour dark schedules. The mice were injected at different stages of their circadian rhythm with either of the hormones. At 4, 8, 12, and 18 hours following the injections, subgroups of seven mice that had been injected 30 minutes earlier with tritiated thymidine were sacrificed. The hormones affected the incorporation of thymidine into DNA in all of the examined organs but in different ways and at different circadian stages. Insulin tended to increase the incorporation in the examined organs whereas glucagon tended to decrease it. When injected either at the end of the dark span or at the beginning of the light span, insulin was more effective in stimulating incorporation of thymidine into DNA. The greatest effect of insulin was in the glandular stomach and rectum while glucagon had the greatest effect on the colon and spleen. The effects of both hormones differed from the effects in relation to epidermal growth factors. The findings indicated that insulin and glucagon were each capable of stimulating thymidine incorporation into DNA in the small intestine. This finding suggested that these hormones should be considered as candidates for the putative villus enlarging factors implied by surgical studies.
NIOSH-Publication; NIOSH-Grant; Neurotoxic-effects; Hormones; Nucleic-acids; Laboratory-animals; Cell-growth; Growth-inhibitors;
Anatomy University of Arkansas 4301 West Markham Little Rock, Ark 72201
Neurotoxic Disorders; Neurotoxic-effects;
University of Arkansas Med Scis Ltl Rock, Little Rock, Arkansas