The effect of a new vitamin D analog, 22-oxa-1 alpha,25(OH)2D3, on bone mineral metabolism in normal male rats.
The in vivo effects of 22-oxa-1 alpha,25 dihydroxyvitamin D3 (OCT), on bone mineral metabolism were investigated in normal male Sprague-Dawley rats. The rats were administered either vehicle (control), low-dose OCT (25 ng/100 g body weight), or high-dose OCT (250 ng/100 g body wt). High-dose OCT increased serum ionized calcium (P less than 0.05) and decreased serum parathyroid hormone (PTH) (P less than 0.05) at all time points and increased serum bone Gla protein on days 7 and 28 (P less than 0.05) compared with controls. Low-dose OCT decreased serum PTH at all the time points (P less than 0.05) compared with controls. Tibial bone histomorphometry showed no significant differences between the two doses of OCT and controls. We found that OCT has minimal direct effects on bone metabolism in normal male rats in contrast to 1,25 dihydroxyvitamin D3. This property may be advantageous in the treatment with OCT of cell-proliferative diseases.
Takizawa
M
M
Division of Endocrinology and Metabolism, Albert Einstein Medical Center, Philadelphia, Pennsylvania 19141.
Fallon
M
M
Stein
B
B
Epstein
S
S
D000704:Analysis of Variance; D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D001842:Bone and Bones / Q000187:drug effects / Q000378:metabolism*; D002117:Calcitriol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D002118:Calcium / Q000097:blood; D008297:Male; D015675:Osteocalcin / Q000097:blood; D010281:Parathyroid Hormone / Q000097:blood; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains
D010281:Parathyroid Hormone; D015675:Osteocalcin; D002117:Calcitriol; C051883:maxacalcitol; D002118:Calcium