Protective Effect of Oxytocin Against Bone Loss in a Female Rat Model of Osteoporosis

Abstract

Background: Introduction: Oxytocin (OT) has been proposed to assist in the regulation of bone remodeling and to exert an antiosteoporotic effect. We evaluated the possible protective effect of OT against bone degeneration in ovariectomized (OVX) rats. Methods: The study was performed on three groups of adult female rats; group I was subjected to sham operation, group II was subjected to ovariectomy, and group III was subjected to ovariectomy and intraperitoneal injection with OT for eight successive weeks. At the end of the study, bone mass density (BMD) was measured; then the rats were euthanized and their blood and bone tissues were examined. Results: The group II rats had significantly less BMD and greater serum bone-specific alkaline phosphatase (bALP), osteocalcin (OC), and tartrate-resistant acid phosphatase (TRAP) levels than the group I rats. Furthermore, group II rats had fewer osteocytes and osteoblasts, and less OPG/RANKL mRNA expression than group I rats. The groups I and III and rats showed no significant differences in BMD, bALP, OC, TRAP, OPG/RANKL mRNA expression, or osteocyte and osteoblast numbers. Conclusions: Oxytocin may have an antiosteoporotic effect in OVX rats.

Oxytocin and Bone: Review and Perspectives

“…In ovariectomized rats, a daily intra-peritoneal injection of OT induces a beneficial effect on the trabecular bone parameters mediated through the restoration of osteoblast/osteoclast cross talk via the RANKL/osteoprotegerin axis [20]. These beneficial effects on the bone density and the microarchitecture of OT systemic administration have been confirmed by other studies in ovariectomized rats and rabbits [21,22].…”

“…Thus, obtaining a molecule that is able to target overall age-related diseases in women would be a dream. As previously discussed, an injection of OT (intra-peritoneal or subcutaneous) preserves and reverses the bone loss induced by estrogen deficiency in animal models [11,21,23,29,54]. Animal models of osteoporosis are not suitable to directly evaluate the efficacy on fracture risk of anti-osteoporotic molecules but use BMD, bone microarchitecture parameters and ex vivo bone strength tests as surrogate markers that are known to predict fracture risk.…”

Lactobacillus reuteri inhibits Staphylococcus aureus‐induced mastitis by regulating oxytocin releasing and gut microbiota in mice

“…OT is an important neuropeptide hormone in the body. In addition to promoting uterine contraction and milk excretion in mammals, OT also has a wide range of physiological and pharmacological effects on gastrointestinal peristalsis, cardiovascular function, body weight, bone remodeling, muscle maintenance and regeneration, cognitive function and immune system regulation 24–27 . In addition, OT has been proven to be a surrogate agent for the treatment of mastitis in dairy cows due to its ability to promote the removal of pathogenic bacteria and reduce the large amount of milk abandonment caused by the use of antibiotics 11 .…”

“…In addition to promoting uterine contraction and milk excretion in mammals, OT also has a wide range of physiological and pharmacological effects on gastrointestinal peristalsis, cardiovascular function, body weight, bone remodeling, muscle maintenance and regeneration, cognitive function and immune system regulation. [24][25][26][27] In addition, OT has been proven to be a surrogate agent for the treatment of mastitis in dairy cows due to its ability to promote the removal of pathogenic bacteria and reduce the large amount of milk abandonment caused by the use of antibiotics. 11 The study showed that intramuscular OT injection for one week significantly reduced S. aureus load in cow's milk with S. aureus-induced mastitis, and there was no significant difference in the cure rate of mastitis and antibiotic treatment.…”

The mechanism of oxytocin and its receptors in regulating cells in bone metabolism

“…Research studies have shown that POT could stimulate ALP activity in OB and upregulate bone morphogenetic protein-2 after POT intervention and also cause the upregulation of BMP-2 through Schnurri-2 and activated transcription factor 4 (ATF4) pathways, thus stimulating OB to differentiate into the mineralized phenotype ( Tamma et al, 2009 ; Qian et al, 2015 ). In addition, Moghazy et al (2020 ) have shown that intraperitoneal administration of POT has an anti-OP effect on rats. The mechanism is associated with the increasing number of osteocytes and OB, the decreasing levels of bone-specific alkaline phosphatase (bALP), osteocalcin, and tartrate-resistant acid phosphatase (TRAP), and the regulation of the expression of the OPG/RANKL pathway.…”