Mechanistic Insights into Melatonin–Calcitonin–Dependent Regulation of Osteoclast Activity Using Goldfish Scales

Exposure to microgravity during spaceflight induces excessive osteoclast activation, resulting in bone loss and dysregulation of calcium metabolism. Accumulating evidence from spaceflight and ground-based studies suggests that endocrine factors involved in osteoclast inhibition may be altered under microgravity conditions; however, the underlying regulatory mechanisms remain incompletely understood.