The effect of dietary vitamin D3 on the intracellular calcium gradient in mammalian colonic crypts.
A physiological gradient in intracellular calcium ([Ca2+]i) has been hypothesized to exist along the colonic crypt base-mouth axis, which may be involved in the regulation of colonocyte proliferation, differentiation and apoptosis. In addition [Ca2+]i may be modulated by dietary vitamin D3 which is thought to be protective against colorectal cancer. CF1 mice were maintained for 6 weeks on a defined diet containing either high or low vitamin D3. A colonic crypt base-mouth [Ca2+]i gradient of 201 +/- 79 nM (mean +/- SEM, P < 0.05) was observed in animals maintained on a high vitamin D3 diet and was abolished in mice maintained on a low vitamin D3 diet. The [Ca2+]i gradient was independent of extracellular calcium and elevated levels of [Ca2+]i observed in the basal regions of the crypt in animals maintained on low levels of vitamin D3 were also associated with an increase in intracellular calcium stores. Therefore, a [Ca2+]i gradient exists in colonic crypts and is dependent on dietary vitamin D3.
Brenner
B M
BM
Department of Surgery, UMD-New Jersey Medical School, Newark, USA.
Russell
N
N
Albrecht
S
S
Davies
R J
RJ
D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002762:Cholecalciferol / Q000494:pharmacology*; D003106:Colon / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D004032:Diet; D005260:Female; D066298:In Vitro Techniques; D051379:Mice
D002762:Cholecalciferol; D002118:Calcium