Shenghua decoction for postpartum hemorrhage attributed to uterine atony: An observational study.

This retrospective study aimed to investigate the preventive effects of Shenghua decoction (SHD) for postpartum hemorrhage (PPH) attributed to uterine atony (UA). Records of 84 patients were retrospectively analyzed, with 42 assigned to the treatment group and 42 to the control group. Both groups received carbetocin, and patients in the treatment group additionally underwent SHD. Primary endpoints included blood loss and changes in hemoglobin levels. Secondary endpoints encompassed the number of patients requiring uterine massage, additional oxytocic drugs, pulse rate, respiratory rate, systolic blood pressure, and treatment-related adverse events. Patients in the treatment group exhibited superior outcomes in terms of blood loss (P < .01), hemoglobin levels (P = .03), and pulse rate (P < .01) compared to those in the control group. However, no significant differences were observed in the number of patients requiring uterine massage (P = .13), the number of patients needing additional oxytocic drugs (P = .19), respiratory rate (P = .05), and systolic blood pressure (P = .80) between the 2 groups. There were no significant disparities in treatment-related adverse events between the 2 groups. The findings of this study suggest that the preventive effects of SHD combined with carbetocin were superior to those of carbetocin alone for preventing postpartum hemorrhage. However, high-quality prospective studies are needed to validate and confirm these results.

A clustering approach identifies an Autism Spectrum Disorder subtype more responsive to chronic oxytocin treatment.

Over the last decade, a number of clinical trials have reported effects of chronic treatment with intranasal oxytocin on autistic symptoms but with inconsistent findings. Autism is a heterogeneous disorder and one factor which may influence treatment outcome is whether a subtype of individuals is more sensitive to oxytocin. In a recent cross-over trial on 41 young autistic children we reported that 44% showed a reliable improvement in clinical symptoms (Autism Diagnostic Observation Schedule, ADOS-2) after a placebo-controlled, 6-week intranasal oxytocin intervention where treatment was given every other day followed by a period of positive social interaction. In the current re-assessment of the data, we used an unsupervised data-driven cluster analysis approach to identify autism subtypes using 23 different demographic, social subtype, endocrine, eye-tracking and clinical symptom measures taken before treatment and this revealed an optimum of two different subtypes. We then assessed the proportion of identified responders to oxytocin and found that while 61.5% of one subtype included responders only 13.3% of the other did so. During the placebo phase there was no difference between the two subtypes for the small proportion of responders (19.2% vs 6.7%). This oxytocin-sensitive subtype also showed overall significant post-treatment clinical and eye-tracking measure changes. The oxytocin-sensitive subtype was primarily characterized at baseline by lower initial clinical severity (ADOS-2) and greater interest in the eye-region of emotional faces. These features alone were nearly as efficient in identifying the two subtypes as all 23 baseline measures and this easy-to-conduct approach may help rapidly and objectively screen for oxytocin responders. Future clinical trials using oxytocin interventions may therefore achieve greater success by focusing on children with this specific autism subtype and help develop individualized oxytocin intervention.

Carbetocin versus oxytocin for the prevention of postpartum haemorrhage during caesarean section in patients at high risk of bleeding.

OBJECTIVE: To evaluate the efficacy of carbetocin versus oxytocin in preventing postpartum haemorrhage (PPH) in women with risk factors for PPH who were delived by caesarean section. METHODS: This retrospective, monocentric, before-and-after cohort study assessed patients with haemorrhagic risk factors who underwent caesarean section after 24 weeks of gestation and who had haemorrhagic risk factors between August 2014 to December 2019. RESULTS: This study enrolled 518 patients, including 250 in the oxytocin group and 268 in the carbetocin group. The use of carbetocin was independently associated with a PPH decrease compared to oxytocin use (adjusted odds ratio [OR]: 0.52; 95 % confidence interval [CI]: 0.35-0.79; p = 0.002). Carbetocin use was associated with a reduction in the need for therapy escalation (6 % vs 10.8 %; p = 0.046). CONCLUSION: Carbetocin was more effective than oxytocin in preventing PPH after caesarean section in high-risk patients.

Intramyometrial and intravenous oxytocin compared to intravenous carbetocin for prevention of postpartum hemorrhage in elective cesarean section-A quasi-randomized controlled phase IV non-inferiority interventional trial.

INTRODUCTION: Our objective was to assess non-inferiority of the unique approach used in our institution of combined 10 IU IM (intramyometrial) and 10 IU IV (intravenous) oxytocin to carbetocin IV in preventing severe postpartum blood loss in elective cesarean sections. The design was a prospective controlled phase IV non-inferiority interventional trial. The setting was a tertiary center at University Hospital, Zurich, Switzerland. MATERIAL AND METHODS: The population consisted of 550 women undergoing elective cesarean section after 36 completed weeks of gestation at low risk for postpartum hemorrhage (PPH). Participants were assigned to either combined oxytocin regimen (10 IU IM and 10 IU IV) or carbetocin (100 µg IV). Non-inferiority for oxytocin for severe PPH was assessed with a 0.05 margin using the Newcombe-Wilson score method. The main outcome measures were severe postpartum blood loss defined as delta hemoglobin (∆Hb, Hb prepartum-Hb postpartum) ≥30 g/L. RESULTS: Non-inferiority of combined oxytocin (IM/IV) in preventing severe postpartum blood loss was not shown (17 women in the oxytocin group vs. 7 in the carbetocin group). The number needed to treat when using carbetocin was 28. The risk difference for ∆Hb ≥30 g/L was 0.04 (oxytocin 0.06 vs. 0.03), 95% confidence interval (CI) (0.00-0.08). No significant difference was observed for ∆Hb (median 12 [IQR 7.0-19.0] vs. 11 [5.0-17.0], p = 0.07), estimated blood loss (median 500 [IQR 400-600] vs. 500 [400-575], p = 0.38), or the PPH rate defined as estimated blood loss ≥1000 mL (12[4.5] vs. 5 [2.0], risk difference 0.03, 95% CI (-0.01 to 0.06), p = 0.16). More additional uterotonics were administered in the oxytocin group compared to the carbetocin group (15.2% vs. 5.9%, p = 0.001). Total case costs were non-significantly different in the oxytocin group (US $ 10 146 vs. 9621, mean difference 471.4, CI (-476.5 to 1419.3), p = 0.33). CONCLUSIONS: Combined (IM/IV) oxytocin is not non-inferior to carbetocin regarding severe postpartum blood loss defined as postpartum Hb decrease ≥30 g/L in elective cesarean sections. We recommend carbetocin for use in clinical practice for elective cesarean sections.

Design and synthesis of oxytocin glycosides for the treatment of pain and substance use disorder.

Peptide drugs are a promising alternative to classical small molecule therapeutics with diverse applications, ranging from antibiotic resistant infection to prostate cancer. Oxytocin (OT) is a highly evolutionarily conserved peptide neurohormone and has been of interest for pharmaceutical use since 1909. Despite their increased safety profile relative to most small molecule drugs, peptides are poor candidates based on the pharmacokinetic (PK) properties from their peptide nature. Broad application of OT as a drug has been limited by these same PK issues. Several strategies have been proposed to overcome these limitations, among them glycosylation, which was used in combination with other sequence modifications to produce robust antinociception in mouse models, increased selectivity and potency at the OT receptor, and improved stability in rats.

Pain modulation by oxytocin.

Oxytocin (OXT) was discovered in 1906 as a substance that promotes the pregnancy and childbirth. It affects uterine contraction and lactation. Furthermore, as one of its physiological properties, it exerts analgesic effects. The living body has an ascending pathway that transmits pain stimuli from the periphery to the center and a descending pathway that regulates the dorsal horn neurons from the upper center downward. OXT is involved in the pain-inhibitory descending pathway and generally assumed to exert analgesic effects. In this article, we describe the pain-suppressive effects of OXT, among its many physiological effects.

Arginine vasopressin deficiency: diagnosis, management and the relevance of oxytocin deficiency.

Polyuria-polydipsia syndrome can be caused by central diabetes insipidus, nephrogenic diabetes insipidus or primary polydipsia. To avoid confusion with diabetes mellitus, the name 'central diabetes insipidus' was changed in 2022 to arginine vasopressin (AVP) deficiency and 'nephrogenic diabetes insipidus' was renamed as AVP resistance. To differentiate the three entities, various osmotic and non-osmotic copeptin-based stimulation tests have been introduced in the past decade. The hypertonic saline test plus plasma copeptin measurement emerged as the test with highest diagnostic accuracy, replacing the water deprivation test as the gold standard in differential diagnosis of the polyuria-polydipsia syndrome. The mainstay of treatment for AVP deficiency is AVP replacement with desmopressin, a synthetic analogue of AVP specific for AVP receptor 2 (AVPR2), which usually leads to rapid improvements in polyuria and polydipsia. The main adverse effect of desmopressin is dilutional hyponatraemia, which can be reduced by regularly performing the so-called desmopressin escape method. Evidence from the past few years suggests an additional oxytocin deficiency in patients with AVP deficiency. This potential deficiency should be further evaluated in future studies, including feasible provocation tests for clinical practice and interventional trials with oxytocin substitution.

The impact of oxytocin on emotion recognition and trust: Does disordered eating moderate these relationships?

OBJECTIVES: The current study aimed to investigate the impact of oxytocin on emotion recognition, trust, body image, affect, and anxiety and whether eating disorder (ED) symptoms moderated any of these relationships. METHOD: Participants (n = 149) were female university students, who were randomly allocated to receive in a double-blind nature, a single dose of oxytocin intranasal spray (n = 76) or a placebo (saline) intranasal spray (n = 73). Participants were asked to complete an experimental measure of emotion recognition and an investor task aimed to assess trust. RESULTS: The oxytocin group exhibited better overall performance on the emotion recognition task (especially with recognising positive emotions), and a decline in state positive affect than the control group at post-intervention. However, these effects were not moderated by ED symptom severity, nor were effects found for state anxiety, negative affect, body image and recognising negative emotions in the emotion recognition task. CONCLUSION: The current findings contribute to the growing literature on oxytocin, emotion recognition and positive affect and suggest that ED pathology does not moderate these relationships. Future research would benefit from examining the efficacy of an oxytocin intervention using a within-subjects, cross-over design, in those with sub-clinical and clinical EDs, as well as healthy controls.

Intranasal oxytocin as a treatment for anxiety and autism: From subclinical to clinical applications.

Animal and human studies have demonstrated that intranasal oxytocin (OT) can penetrate the brain and induce cognitive, emotional, and behavioral changes, particularly in social functioning. Consequently, numerous investigations have explored the potential of OT as a treatment for anxiety and autism, conditions characterized by social deficits. Although both subclinical and clinical studies provide converging evidence of the therapeutic effects of OT in reducing anxiety levels and improving social symptoms in autism, results are not always consistent. Additionally, the pharmacological mechanism of OT requires further elucidation for its effective clinical application. Therefore, this review aims to examine the contentious findings concerning the effects of OT on anxiety and autism, offer interpretations of the inconsistent results from the perspectives of individual differences and varying approaches to OT administration, and shed light on the underlying mechanisms of OT. Ultimately, standardization of dosage, frequency of administration, formulation characteristics, and nasal spray devices is proposed as essential for future human studies and clinical applications of OT treatment.

Design of a randomized clinical trial of brief couple therapy for PTSD augmented with intranasal oxytocin.

BACKGROUND: Leveraging military veterans' intimate relationships during treatment has the potential to concurrently improve posttraumatic stress disorder (PTSD) symptoms and relationship quality. Cognitive-Behavioral Conjoint Therapy (CBCT) and an 8-session Brief Cognitive-Behavioral Conjoint Therapy (bCBCT) are manualized treatments designed to simultaneously improve PTSD and relationship functioning for couples in which one partner has PTSD. Although efficacious in improving PTSD, the effects of CBCT on relationship satisfaction are small, especially among veterans. Intranasal oxytocin, which targets mechanisms of PTSD and relationship quality, may enhance the efficacy of bCBCT. METHOD/DESIGN: The purpose of this 4-year clinical trial is to compare the outcomes of bCBCT augmented with intranasal oxytocin versus bCBCT plus placebo. We will also explore potential mechanisms of action: self-reported communication skills, empathy, and trust. We will recruit 120 dyads (i.e., veteran with PTSD and their intimate partner) from the VA San Diego Healthcare System. Veterans will be administered 40 international units of oxytocin (n = 60) or placebo (n = 60) 30 min before each of 8 bCBCT sessions delivered via telehealth. Clinical and functioning outcomes will be assessed at five timepoints (baseline, mid-treatment, post-treatment, and 3- and 6-month follow-up). CONCLUSION: Study findings will reveal the efficacy of oxytocin-assisted brief couple therapy for PTSD, which could serve as highly scalable option for couples coping with PTSD, as well as provide preliminary evidence of interpersonal mechanisms of change. CLINICALTRIALS: govIdentifier:NCT06194851.

Potential role of oxytocin in the regulation of memories and treatment of memory disorders.

Oxytocin (OXT) is an "affiliative" hormone or neurohormone or neuropeptide consists of nine amino acids, synthesized in magnocellular neurons of paraventricular (PVN) and supraoptic nuclei (SON) of hypothalamus. OXT receptors are widely distributed in various region of brain and OXT has been shown to regulate various social and nonsocial behavior. Hippocampus is the main region which regulates the learning and memory. Hippocampus particularly regulates the acquisition of new memories and retention of acquired memories. OXT has been shown to regulate the synaptic plasticity, neurogenesis, and consolidation of memories. Further, findings from both preclinical and clinical studies have suggested that the OXT treatment improves performance in memory related task. Various trials have suggested the positive impact of intranasal OXT in the dementia patients. However, these studies are limited in number. In the present study authors have highlighted the role of OXT in the formation and retrieval of memories. Further, the study demonstrated the outcome of OXT treatment in various memory and related disorders.

Third stage of labor: evidence-based practice for prevention of adverse maternal and neonatal outcomes.

The third stage of labor is defined as the time period between delivery of the fetus through delivery of the placenta. During a normal third stage, uterine contractions lead to separation and expulsion of the placenta from the uterus. Postpartum hemorrhage is a relatively common complication of the third stage of labor. Strategies have been studied to mitigate the risk of postpartum hemorrhage, leading to the widespread implementation of active management of the third stage of labor. Initially, active management of the third stage of labor consisted of a bundle of interventions including administration of a uterotonic agent, early cord clamping, controlled cord traction, and external uterine massage. However, the effectiveness of these interventions as a bundle has been questioned, leading to abandonment of some components in recent years. Despite this, upon review of selected international guidelines, we found that the term "active management of the third stage of labor" was still used, but recommendations for and against individual interventions were variable and not necessarily supported by current evidence. In this review, we: (1) examine the physiology of the third stage of labor, (2) present evidence related to interventions that prevent postpartum hemorrhage and promote maternal and neonatal health, (3) review current global guidelines and recommendations for practice, and (4) propose future areas of investigation. The interventions in this review include pharmacologic agents to prevent postpartum hemorrhage, cord clamping, cord milking, cord traction, cord drainage, early skin-to-skin contact, and nipple stimulation. Treatment of complications of the third stage of labor is outside of the scope of this review. We conclude that current evidence supports the use of effective pharmacologic postpartum hemorrhage prophylaxis, delayed cord clamping, early skin-to-skin contact, and controlled cord traction at delivery when feasible. The most effective uterotonic regimens for preventing postpartum hemorrhage after vaginal delivery include oxytocin plus ergometrine; oxytocin plus misoprostol; or carbetocin. After cesarean delivery, carbetocin or oxytocin as a bolus are the most effective regimens. There is inconsistent evidence regarding the use of tranexamic acid in addition to a uterotonic compared with a uterotonic alone for postpartum hemorrhage prevention after all deliveries. Because of differences in patient comorbidities, costs, and availability of resources and staff, decisions to use specific prevention strategies are dependent on patient- and system-level factors. We recommend that the term "active management of the third stage of labor" as a combined intervention no longer be used. Instead, we recommend that "third stage care" be adopted, which promotes the implementation of evidence-based interventions that incorporate practices that are safe and beneficial for both the woman and neonate.

Tafoxiparin, a novel drug candidate for cervical ripening and labor augmentation: results from 2 randomized, placebo-controlled studies.

BACKGROUND: Slow progression of labor is a common obstetrical problem with multiple associated complications. Tafoxiparin is a depolymerized form of heparin with a molecular structure that eliminates the anticoagulant effects of heparin. We report on 2 phase II clinical studies of tafoxiparin in primiparas. Study 1 was an exploratory, first-in-pregnant-women study and study 2 was a dose-finding study. OBJECTIVE: Study 1 was performed to explore the effects on labor time of subcutaneous administration of tafoxiparin before onset of labor. Study 2 was performed to test the hypothesis that intravenous treatment with tafoxiparin reduces the risk for prolonged labor after spontaneous labor onset in situations requiring oxytocin stimulation because of dystocia. STUDY DESIGN: Both studies were randomized, double-blind, and placebo-controlled. Participants were healthy, nulliparous females aged 18 to 45 years with a normal singleton pregnancy and gestational age confirmed by ultrasound. The primary endpoints were time from onset of established labor (cervical dilation of 4 cm) until delivery (study 1) and time from start of study treatment infusion until delivery (study 2). In study 1, patients at 38 to 40 weeks of gestation received 60 mg tafoxiparin or placebo daily as 0.4 mL subcutaneous injections until labor onset (maximum 28 days). In study 2, patients experiencing slow progression of labor, a prolonged latent phase, or labor arrest received a placebo or 1 of 3 short-term tafoxiparin regimens (initial bolus 7, 21, or 35 mg followed by continuous infusion at 5, 15, or 25 mg/hour until delivery; maximum duration, 36 hours) in conjunction with oxytocin. RESULTS: The number of participants randomized in study 1 was 263, and 361 were randomized in study 2. There were no statistically significant differences in the primary endpoints between those receiving tafoxiparin and those receiving the placebo in both studies. However, in study 1, the risk for having a labor time exceeding 12 hours was significantly reduced by tafoxiparin (tafoxiparin 6/114 [5%] vs placebo 18/101 [18%]; P=.0045). Post hoc analyses showed that women who underwent labor induction had a median (range) labor time of 4.44 (1.2-8.5) hours with tafoxiparin and 7.03 (1.5-14.3) hours with the placebo (P=.0041) and that co-administration of tafoxiparin potentiates the effect of oxytocin and facilitates a shorter labor time among women with a labor time exceeding 6 to 8 hours (P=.016). Among women induced into labor, tafoxiparin had a positive effect on cervical ripening in 11 of 13 cases (85%) compared with 3 of 13 participants (23%) who received the placebo (P=.004). For women requiring oxytocin because of slow progression of labor, the corresponding results were 34 of 51 participants (66%) vs 16 of 40 participants (40%) (P=.004). In study 2, tafoxiparin had no positive effects on the secondary endpoints when compared with the placebo. Except for injection-site reactions in study 1, adverse events were no more common for tafoxiparin than for the placebo among either mothers or infants. There were few serious or treatment-related adverse events. CONCLUSION: Subcutaneous treatment with tafoxiparin before labor onset (study 1) may be effective in reducing the labor time among women undergoing labor induction and among those requiring oxytocin for slow progression of labor. Moreover, tafoxiparin may have a positive effect on cervical ripening. Short-term, intravenous treatment with tafoxiparin as an adjunct to oxytocin in patients with labor arrest (study 2) did not affect labor time or other endpoints. Both studies suggest that tafoxiparin has a favorable safety profile in mothers and their infants.

Tranexamic acid versus oxytocin for primary postpartum Haemorrhage in the out-of-hospital setting: A systematic review with implications for rural practice.

INTRODUCTION: Primary postpartum haemorrhage causes approximately 25% of global maternal deaths and accounts for significant maternal morbidity. While high certainty evidence demonstrates that tranexamic acid reduces comparative blood loss in postpartum haemorrhage in hospital settings, limited data exist on the specific pharmacological management of this condition in out-of-hospital settings, and the implications for rural communities. OBJECTIVE: To determine the efficacy of oxytocin compared to tranexamic acid in women suffering postpartum haemorrhage in the out-of-hospital environment. DESIGN: A systematic review comparing evidence containing patients with postpartum haemorrhage in the out-of-hospital and/or rural setting, in which oxytocin/tranexamic acid were used. Outcome measures were comparative blood loss/haemorrhagic shock, the need for further interventions and maternal/neonatal morbidity/mortality. FINDINGS: No randomised control trials have been conducted in an out-of-hospital environment in relation to oxytocin/tranexamic acid. In this setting, there is no difference in outcome measures when using oxytocin compared to no intervention, or oxytocin compared to standard care. Data are lacking on the effect of tranexamic acid on the same outcome measures. DISCUSSION: Rural and out-of-hospital management of postpartum haemorrhage is limited by resource availability and practitioner availability, capacity and experience. In-hospital evidence may lack transferability, therefore direct evidence on the efficacy of pharmacological management in these contexts is scant and requires redress. CONCLUSION: There is no difference in blood loss, neonatal or maternal mortality or morbidity, or need for further interventions, when using oxytocin or TXA compared to no intervention, or compared to standard care, for PPH. Further studies are needed on the efficacy of these drugs, and alternate or co-drug therapies, for PPH in the out-of-hospital environment and rural clinical practice.

Neural Responses to Intranasal Oxytocin in Youths With Severe Irritability.

OBJECTIVE: The authors investigated the neural impact of intranasal oxytocin on emotion processing areas in youths with severe irritability in the context of disruptive mood and behavior disorders. METHODS: Fifty-two participants with severe irritability, as measured by a score ≥4 on the Affective Reactivity Index (ARI), with diagnoses of disruptive behavior disorders (DBDs) and/or disruptive mood dysregulation disorder (DMDD) were randomly assigned to treatment with intranasal oxytocin or placebo daily for 3 weeks. Assessments were conducted at baseline and at the end of the trial; the primary outcomes were measures of irritability on the ARI and ratings on the Clinical Global Impressions severity scale (CGI-S) focusing on DBD and DMDD symptoms, and secondary outcomes included the CGI improvement scale (CGI-I) and ratings of proactive and reactive aggressive behavior on the Reactive-Proactive Aggression Questionnaire. Forty-three participants (22 in the oxytocin group and 21 in the placebo group) completed pre- and posttreatment functional MRI (fMRI) scans with the affective Stroop task. RESULTS: Youths who received oxytocin showed significant improvement in CGI-S and CGI-I ratings compared with those who received placebo. In the fMRI data, blood-oxygen-level-dependent (BOLD) responses to emotional stimuli in the dorsomedial prefrontal cortex and posterior cingulate cortex were significantly reduced after oxytocin compared with placebo. These BOLD response changes were correlated with improvement in clinical severity. CONCLUSIONS: This study provides initial and preliminary evidence that intranasal oxytocin may induce neural-level changes in emotion processing in youths with irritability in the context of DBDs and DMDD. This may lead to symptom and severity changes in irritability.

Effects of the WHO Labour Care Guide on cesarean section in India: a pragmatic, stepped-wedge, cluster-randomized pilot trial.

Cesarean section rates worldwide are rising, driven by medically unnecessary cesarean use. The new World Health Organization Labour Care Guide (LCG) aims to improve the quality of care for women during labor and childbirth. Using the LCG might reduce overuse of cesarean; however, its effects have not been evaluated in randomized trials. We conducted a stepped-wedge, cluster-randomized pilot trial in four hospitals in India to evaluate the implementation of an LCG strategy intervention, compared with routine care. We performed this trial to pilot the intervention and obtain preliminary effectiveness data, informing future research. Eligible clusters were four hospitals with >4,000 births annually and cesarean rates ≥30%. Eligible women were those giving birth at ≥20 weeks' gestation. One hospital transitioned to intervention every 2 months, according to a random sequence. The primary outcome was the cesarean rate among women in Robson Group 1 (that is, those who were nulliparous and gave birth to a singleton, term pregnancy in cephalic presentation and in spontaneous labor). A total of 26,331 participants gave birth. A 5.5% crude absolute reduction in the primary outcome was observed (45.2% versus 39.7%; relative risk 0.85, 95% confidence interval 0.54-1.33). Maternal process-of-care outcomes were not significantly different, though labor augmentation with oxytocin was 18.0% lower with the LCG strategy. No differences were observed for other health outcomes or women's birth experiences. These findings can guide future definitive effectiveness trials, particularly in settings where urgent reversal of rising cesarean section rates is needed. Clinical Trials Registry India number: CTRI/2021/01/030695 .

Oxytocin alleviates periodontitis in adult rats.

OBJECTIVE: The objective of the study was to evaluate the expression of oxytocin receptors in normal and inflamed gingiva, as well as the effects of systemic administration of oxytocin in bone loss and gum inflammatory mediators in a rat model of experimental periodontitis. BACKGROUND DATA: Current evidence supports the hypothesis of a disbalance between the oral microbiota and the host's immune response in the pathogenesis of periodontitis. Increased complexity of the microbial biofilm present in the periodontal pocket leads to local production of nitrogen and oxygen-reactive species, cytokines, chemokines, and other proinflammatory mediators which contribute to periodontal tissue destruction and bone loss. Oxytocin has been suggested to participate in the modulation of immune and inflammatory processes. We have previously shown that oxytocin, nitric oxide, and endocannabinoid system interact providing a mechanism of regulation for systemic inflammation. Here, we aimed at investigating not only the presence and levels of expression of oxytocin receptors on healthy and inflamed gingiva, but also the effects of oxytocin treatment on alveolar bone loss, and systemic and gum expression of inflammatory mediators involved in periodontal tissue damage using ligature-induced periodontitis. Therefore, anti-inflammatory strategies oriented at modulating the host's immune response could be valuable adjuvants to the main treatment of periodontal disease. METHODS: We used an animal model of ligature-induced periodontitis involving the placement of a linen thread (Barbour flax 100% linen suture, No. 50; size 2/0) ligature around the neck of first lower molars of adult male rats. The ligature was left in place during the entire experiment (7 days) until euthanasia. Animals with periodontitis received daily treatment with oxytocin (OXT, 1000 µg/kg, sc.) or vehicle and/or atosiban (3 mg/kg, sc.), an antagonist of oxytocin receptors. The distance between the cement-enamel junction and the alveolar bone crest was measured in stained hemimandibles in the long axis of both buccal and lingual surfaces of both inferior first molars using a caliper. TNF-α levels in plasma were determined using specific rat enzyme-linked immunosorbent assays (ELISA). OXT receptors, IL-6, IL-1ß, and TNF-α expression were determined in gingival tissues by semiquantitative or real-time PCR. RESULTS: We show that oxytocin receptors are expressed in normal and inflamed gingival tissues in male rats. We also show that the systemic administration of oxytocin prevents the experimental periodontitis-induced increased gum expression of oxytocin receptors, TNF-α, IL-6, and IL-1ß (p < .05). Furthermore, we observed a reduction in bone loss in rats treated with oxytocin in our model. CONCLUSIONS: Our results demonstrate that oxytocin is a novel and potent modulator of the gingival inflammatory process together with bone loss preventing effects in an experimental model of ligature-induced periodontitis.

Effects of systemic oxytocin administration on ultraviolet B-induced nociceptive hypersensitivity and tactile hyposensitivity in mice.

Ultraviolet B (UVB) radiation induces cutaneous inflammation, leading to thermal and mechanical hypersensitivity. Here, we examine the mechanical properties and profile of tactile and nociceptive peripheral afferents functionally disrupted by this injury and the role of oxytocin (OXT) as a modulator of this disruption. We recorded intracellularly from L4 afferents innervating the irradiated area (5.1 J/cm2) in 4-6 old week male mice (C57BL/6J) after administering OXT intraperitoneally, 6 mg/Kg. The distribution of recorded neurons was shifted by UVB radiation to a pattern observed after acute and chronic injuries and reduced mechanical thresholds of A and C- high threshold mechanoreceptors while reducing tactile sensitivity. UVB radiation did not change somatic membrane electrical properties or fiber conduction velocity. OXT systemic administration rapidly reversed these peripheral changes toward normal in both low and high-threshold mechanoreceptors and shifted recorded neuron distribution toward normal. OXT and V1aR receptors were present on the terminals of myelinated and unmyelinated afferents innervating the skin. We conclude that UVB radiation, similar to local tissue surgical injury, cancer metastasis, and peripheral nerve injury, alters the distribution of low and high threshold mechanoreceptors afferents and sensitizes nociceptors while desensitizing tactile units. Acute systemic OXT administration partially returns all of those effects to normal.

The Oxytocin Puzzle: Unlocking Alzheimer's Disease.

Alzheimer's disease is a multi-factorial disease that disrupts many aspects of human behavior. In this comment, we highlight the work by Koulousakis et al. published in a recent issue of the Journal of Alzheimer's Disease. In this study, the authors tested the therapeutic potential of the neuropeptide oxytocin in a pre-clinical model of Alzheimer's disease and found positive behavioral outcomes on memory assessments. We discuss these findings in the context of oxytocin research in the field of Alzheimer's disease and the literature regarding oxytocin-based therapeutics, including administration protocols and potential underlying cellular and molecular mechanisms.