Phototherapy-induced hypocalcemia in newborn rats: prevention by melatonin

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Science  13 Nov 1981:
Vol. 214, Issue 4522, pp. 807-809
DOI: 10.1126/science.6895262


When young rats are exposed to white fluorescent light the concentration of calcium in their serum decreases. This effect is prevented by shielding the occiput, by inhibiting corticosterone synthesis, and by exogenous melatonin. Furthermore, the expected hypocalcemic response to cortisol injection is prevented by melatonin. Light-induced hypocalcemia may result from increased calcium uptake by bone when the blocking effect of melatonin decreases after pineal inhibition by transcranial illumination.