Background: Evidence has shown that endogenous H2S plays an important role in the physiological and pathophysiological processes of many organs. The study aimed to explore whether exogenous H2S has a potential therapeutic effect on a rat ovariectomy-induced model of osteoporosis.
Methods: The OVX osteoporosis model was established in female Sprague-Dawley rats by full bilateral ovariectomy. The rats were randomly divided into four groups, with the two experimental groups receiving an intraperitoneal injection of GYY4137 or sodium alendronate. The level of H2S in the plasma was determined and common laboratory indicators to diagnose osteoporosis, such as alkaline phosphatase (ALP) activity and the levels of osteocalcin (OCN), calcitonin, parathyroid hormone and leptin were measured. The bone mineral density (BMD) of the 4th and 5th lumbar vertebrae was measured using dual-energy X-ray absorptiometry. The maximum stress of femoral fracture was obtained through a three-point bending test of the femur.
Results: The OVX osteoporosis model was successfully established. GYY4137 was injected to increase the level of H2S in the plasma in one group, designated OVX-GYY during the observation period (p < 0.05). At 12 weeks, the BMD value of the fourth lumbar vertebra in the OVX-GYY group had increased (p < 0.05). The BMD femur value in the OVX-vehicle group had decreased (p < 0.05). Bilateral ovariectomy leads to biochemical disorders related to bone metabolism and hormone levels in rat plasma (all p < 0.05). Ovariectomy also reduced blood calcium, blood phosphate and calcitonin, and increased parathyroid hormone and leptin. The opposite results were obtained for the groups with alendronate sodium or GYY4137 treatment (all p < 0.05).
Conclusions: Through the slow release of H2S, GYY4137 did an excellent job of simulating endogenous neuroendocrine gaseous signaling molecules. Exogenous H2S had a regulatory effect on osteoporosis in ovariectomized rats, showing potential value for the treatment of human postmenopausal osteoporosis.
Keywords: Bone metabolism; Bone mineral density; H2S; Osteoporosis; Ovariectomized.