CNP and secondary hyperparathyroidism: In the present study, we probed the therapeutic effect of CNP on both uremia and ROD progression and revealed that renal function, calcium phosphate metabolic disorders, hypovitaminosis D, secondary hyperparathyroidism, and decreased bone turnover markers were restored by CNP to some extent; directly, CNP injection could also improve bone pathological changes through increasing osteoblasts, osteoclasts, osteoid volume, and trabecular thickness in the uremic rats.