Effects of salmon calcitonin on calcium deposition on and release from calcified tissues in fed and starved goldfish Carassius auratus

Effects of salmon calcitonin on calcium physiology of the otolith, rib bone , pharyngeal bone, and scale were examined in fed and starved goldfish Cara ssius auratus. Fish were intraperitoneally given salmon calcitonin at a dos e of 10 ng/g body weight four times every other day. They were then incubat ed in Ca-45-containing water for 24 h to examine the effect of the hormone on calcium deposition on these tissues. Another group of goldfish was incub ated in Ca-45-bone water for 2 days to prelabel the tissues with Ca-45. The n they were kept in Ca-45-free water for 8 days, during which they were giv en calcitonin four times every other day. The effect of calcitonin on calci um release from the tissues was examined by analyzing the prelabeled radioa ctivity. Calcitonin had no effect on plasma calcium concentrations or on ca lcium deposition in any of the tissues in fed fish. In starved fish, howeve r, calcitonin increased calcium deposition on the rib bone, pharyngeal bone , and scale. In the starved fish, plasma calcium levels were not affected b y the hormone, but plasma Ca-45 activity was lower in the calcitonin-treate d group than in the control group. Calcitonin had no effect on calcium rele ase from the bone and the scale, but reduced radioactivity in the otoliths of fed fish. These results suggest that calcitonin functions as an accelera tor for calcium deposition on the bone and the scale in starved goldfish.