Tissue distribution of the 1,25-dihydroxyvitamin D3 receptor in the male rat.
Tissue distribution of 1,25-dihydroxyvitamin D3 receptors was studied in male rats using a quantitative immunoradiometric assay. Extracts were prepared from 16 different rat tissues and assayed for 1,25-dihydroxyvitamin D3 receptor. Measurable levels of receptor were detected in intestine, stomach, kidney, bone thyroid/parathyroid, skin, liver, spleen, heart and lung. The highest levels were found in the proximal small intestine and colon, containing over 1000 fmol/mg total protein, while ileum and kidney contained one-half and one-fourth of this amount, respectively. Other parts of the vitamin D endocrine system, including bone, thyroid/parathyroid and skin, contained moderate levels of receptor of 40 to 80 fmol/mg, while lung, heart, stomach, spleen and liver had levels at or below 20 fmol/mg. No 1,25-dihydroxyvitamin D3 receptor was detected in cerebrum, cerebellum or skeletal muscle. The data support a wide-spread role for 1,25-dihydroxyvitamin D3 on cellular processes and suggest a more important role for vitamin D in colon.
Sandgren
M E
ME
Department of Biochemistry, University of Wisconsin-Madison 53706.
Brönnegärd
M
M
DeLuca
H F
HF
D000818:Animals; D003106:Colon / Q000737:chemistry; D015592:Immunoradiometric Assay; D007421:Intestine, Small / Q000737:chemistry; D007668:Kidney / Q000737:chemistry; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D018167:Receptors, Calcitriol; D011987:Receptors, Steroid / Q000032:analysis*; D012867:Skin / Q000737:chemistry; D014018:Tissue Distribution
D018167:Receptors, Calcitriol; D011987:Receptors, Steroid