Plasma calcium and stanniocalcin levels of male tilapia, Oreochromis mossambicus, fed calcium-deficient food and treated with 1,25 dihydroxyvitamin D3.
The vitamin D metabolite 1,25 dihydroxyvitamin D3 (1,25(OH)2D3; calcitriol) was injected ip (5 microg/kg-1 body mass daily) into male tilapia, Oreochromis mossambicus, fed calcium-deficient food. Plasma calcium (total and free) and stanniocalcin levels, as well as calcium contents of vertebral and opercular bone and scales, were determined on days 1, 3, and 5. In the treated fish, total plasma calcium levels increased on days 3 and 5. Plasma-free calcium levels remained unaffected. Plasma stanniocalcin levels increased, indicating a response of the Stannius corpuscles to redress 1, 25(OH)2D3-induced hypercalcemia. The calcium contents of bone, operculum, and scales were unchanged. It is concluded that in fish, which lack parathyroid hormone, 1,25(OH)2D3 is hypercalcemic and its action is independent of dietary calcium.
Srivastav
A K
AK
Department of Zoology, University of Gorakhpur, Gorakhpur, 273 009, India.
Flik
G
G
Wendelaar Bonga
S E
SE
D000818:Animals; D001842:Bone and Bones / Q000737:chemistry / Q000187:drug effects; D002117:Calcitriol / Q000008:administration & dosage*; D002118:Calcium / Q000097:blood* / Q000172:deficiency*; D002136:Calcium, Dietary / Q000008:administration & dosage* / Q000097:blood; D006023:Glycoproteins / Q000097:blood*; D006728:Hormones / Q000097:blood*; D006996:Hypocalcemia / Q000097:blood; D007274:Injections, Intraperitoneal; D008297:Male; D017210:Tilapia / Q000097:blood*
D002136:Calcium, Dietary; D006023:Glycoproteins; D006728:Hormones; C051795:teleocalcin; D002117:Calcitriol; D002118:Calcium