Tissue distribution and vitamin D dependence of IMCAL in the rat
Integral membrane calcium-binding protein (IMCAL) is a vitamin D-dependent integral membrane protein that binds calcium with relatively high affinity. Specific immunoassays for IMCAL utilizing rabbit polyclonal and mouse monoclonal antibodies were developed and applied to studies of its tissue distribution and regulation by vitamin D/sub 3/ and dietary calcium in the rat. The results indicate that vitamin D-dependent, cross-reactive protein is present in small intestinal mucosa, cecal mucosa, bone, kidney, brain, testis, heart, lung, spleen, and skin. Rats maintained on a low- (0.02%) compared with a high- (2.0%) calcium diet had significantly higher content of IMCAL in duodenal mucosa, cecal mucosa, bone, kidney, brain, testis, and heart. Treatment of rats on the high-calcium diet with 1,25-dihydroxyvitamin D/sub 3/ increased the IMCAL content of the duodenal mucosa, cecal mucosa, and kidney. The widespread tissue distribution of vitamin D-dependent IMCAL, its close correlation in intestinal mucosa with the calcium transport mechanism, and its occurrence in isolated preparations of enterocyte plasma membranes (microvillus and basolateral membranes) suggest that the protein is involved in the regulation of calcium flux in a number of cell types.
- Research Organization:
- Columbia Univ. College of Physicians and Surgeons, New York, NY (USA)
- OSTI ID:
- 6863507
- Journal Information:
- Am. J. Physiol.; (United States), Vol. 253:3
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
CHOLECALCIFEROL
BIOCHEMISTRY
LABELLED COMPOUNDS
TISSUE DISTRIBUTION
PROTEINS
RADIOIMMUNOASSAY
BRAIN
CALCIUM COMPOUNDS
ELECTROPHORESIS
HEART
IODINE 125
KIDNEYS
LUNGS
MEMBRANE TRANSPORT
MUCOUS MEMBRANES
SKIN
SMALL INTESTINE
SPLEEN
TESTES
ALKALINE EARTH METAL COMPOUNDS
BETA DECAY RADIOISOTOPES
BODY
CARDIOVASCULAR SYSTEM
CENTRAL NERVOUS SYSTEM
CHEMISTRY
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DISTRIBUTION
ELECTRON CAPTURE RADIOISOTOPES
GASTROINTESTINAL TRACT
GONADS
IMMUNOASSAY
IMMUNOLOGY
INTERMEDIATE MASS NUCLEI
INTESTINES
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MALE GENITALS
MEMBRANES
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
RADIOASSAY
RADIOIMMUNOLOGY
RADIOISOTOPES
RESPIRATORY SYSTEM
TRACER TECHNIQUES
VITAMIN D
VITAMINS
550601* - Medicine- Unsealed Radionuclides in Diagnostics
551001 - Physiological Systems- Tracer Techniques