Doppler Imaging Assessment of Changes of Blood Flow in Adenomyosis After Higher-Dose Oxytocin: A Randomized Controlled Trial

OBJECTIVES

To assess the changes of blood flow in adenomyosis (AM) after higher-dose oxytocin (OT) in different doses, and to evaluate the safety for patients.

METHODS

A total of 124 patients with AM were randomly divided into 4 groups with continuous intravenous infusion of OT as 0.06, 0.12, 0.24 and 0.36 U/min, respectively. The changes of arteries of AM before and after intravenous infusion of OT were observed by color Doppler ultrasound. The changes of blood flow volume of the artery of AM before and after intravenous infusion of OT were compared among the 4 groups, and the vital signs and adverse drug reactions were monitored during intravenous drip.

RESULTS

During the trial, no severe adverse reactions occurred and the vital signs of all the patients were stable. Among the 4 groups, it was found that there was a significant difference in the change of blood flow volume of blood artery in AM lesions between 0.06 U/min OT group and the other three groups after intravenous drip of OT (P < .05), but there was no significant difference in blood flow volume among the three groups (P > .05), and the difference of adverse drug reactions was statistically significant with the increase of OT dose (P < .05).

CONCLUSION

OT can effectively reduce the blood flow volume of AM lesions, and continuous intravenous infusion of 0.12 U/min OT is an appropriate dose that can not only minimize the blood flow volume but also reduce the incidence of adverse drug reactions.

Ultrastructural Evidence for Oxytocin and Oxytocin Receptor at the Spinal Dorsal Horn: Mechanism of Nociception Modulation

Oxytocin is a hypothalamic neuropeptide involved in the inhibition of nociception transmission at spinal dorsal horn (SDH) level (the first station where the incoming peripheral signals is modulated). Electrophysiological, behavioral, and pharmacological data strongly support the role of this neuropeptide and its receptor (the oxytocin receptor, OTR) as a key endogenous molecule with analgesic properties. Briefly, current data showed that oxytocin release from the hypothalamus induces OTR activation at the SDH, inducing selective inhibition of the nociceptive Aδ- and C-fibers (probably peptidergic) activity, but not the activity of proprioceptive fibers (i.e. Aβ-fibers). The above inhibition could be a direct presynaptic mechanism, or a mechanism mediated by GABAergic interneurons. However, the exact anatomical localization of oxytocin and OTR remains unclear. In this context, the present study set out to analyze the role of OTRs, GABAergic cells and CGRP fibers in the SDH in rats by using electron microscopy. Ultrastructural analyses of the SDH tissue show that: (i) oxytocin and OTR are found in asymmetrical synapsis; (ii) OTR is found in GABAergic interneurons (near unmyelinated fibers), CGRPergic fibers and glial cells; (iii) whereas oxytocin is present in supraspinal descending projection fibers. These anatomical data strongly support the notion that oxytocin released at the SDH could presynaptically inhibit the nociceptive input from the peripheral primary afferent fibers. This inhibitory action could be direct or use a GABA interneuron. Furthermore, our findings that OTR is exhibited in glial tissue at the SDH requires further exploration in nociception assays.

Oxytocin infusion reduces bleeding during abdominal myomectomies: a randomized controlled trial

PURPOSE

To evaluate the effectiveness of oxytocin infusion to reduce intraoperative bleeding during abdominal myomectomies.

METHODS

This randomized, parallel group, blinded study was conducted between October 2017 and May 2018. Patients undergoing abdominal myomectomies were randomized 1:1 either to the oxytocin group or to the control group (saline). In the oxytocin group, 10 IU oxytocin in 500 ml of saline at a rate of 120 ml/h was given during the course of the operation. The primary outcome of this study was to measure intraoperative blood loss between the study groups. Correlation and multiple regression analysis were performed to illustrate factors associated with intraoperative blood loss during the myomectomy.

RESULTS

The mean intraoperative blood loss during the surgery was 489.20 ± 239.72 ml in the oxytocin group and was 641.40 ± 288.21 ml in the control group. The hemoglobin decline was more evident in the control group than in the oxytocin group. Positive correlations were also observed between the intraoperative blood loss and number of fibroids removed during the surgery, largest fibroid removed and weight of fibroids removed. The use of oxytocin infusion during the myomectomy resulted in a reduction of bleeding in the regression model.

CONCLUSION

Intravenous oxytocin infusion is a safe and practical method to reduce intraoperative blood loss during the abdominal myomectomy.

Oxytocin infusion in laparoscopic myomectomy may decrease operative blood loss

STUDY OBJECTIVE

To evaluate the influence of oxytocin on operative blood loss during laparoscopic myomectomy (LM).

DESIGN

Prospective clinical study (Canadian Task Force classification I).

SETTING

Tertiary care university hospital.

PATIENTS

Sixty women scheduled for myomectomy because of symptomatic uterine myomas.

INTERVENTION

Two ampules of oxytocin (10 u/mL/amp) were added to 1000 mL of saline solution running at the rate of 40 mU/min during the course of LM.

MEASUREMENTS AND MAIN RESULTS

Blood loss and blood transfusion rate were significantly greater in the group without oxytocin infusion (group B) than in the group with oxytocin infusion (group A), with 445.0 +/- 268.6 mL (95% CI 344.7-545.3) versus 269.5 +/- 225.8 mL (95% CI 185.2-353.8)/(p <.05), and 36.7% versus 6.7% (p <.05), respectively. There was no significant difference in average age, body weight, or numbers of vaginal delivery and cesarean sections between the 2 groups. There was no significant difference in mean total myoma weight, main myoma size, postoperative stay, and complications between the 2 groups.

CONCLUSION

Oxytocin infusion combined with skillful surgical techniques may decrease operative blood loss and blood transfusion during LM.

Oxytocin induces proliferation and migration in immortalized human dermal microvascular endothelial cells and human breast tumor-derived endothelial cells

Oxytocin either increases or inhibits cell growth in different cell subtypes. We tested here the effect of oxytocin on cell proliferation and migration of human dermal microvascular endothelial cells (HMEC) and tumor-associated endothelial cells purified from human breast carcinomas (B-TEC). Oxytocin receptors were expressed in both cell subtypes at mRNA and protein levels. Through oxytocin receptor, oxytocin (1 nmol/L-1 mumol/L) significantly increased cell proliferation and migration in both HMEC and B-TEC, and addition of a selective oxytocin antagonist fully reverted these effects. To verify whether a different expression of adhesion molecule-related genes could be responsible for the oxytocin-induced cell migration, untreated and treated cells were compared applying a microarray technique. In HMEC, oxytocin induced the overexpression of the matrix metalloproteinase (MMP)-17, cathepsin D, and integrin beta(6) genes. In B-TEC, oxytocin significantly switched on the gene profile of some MMP (MMP-11 and MMP-26) and of integrin beta(6). The up-regulation of the integrin beta(6) gene could be involved in the oxytocin-induced cell growth, because this subunit is known to determine activation of mitogen-activated protein kinase-extracellular signal-regulated kinase 2, which is involved in the oxytocin mitogenic effect. In B-TEC, oxytocin also increased the expression of caveolin-1 at gene and protein levels. Because oxytocin receptor localization within caveolin-1-enriched membrane domains is necessary for activation of the proliferative (instead of the inhibitory) response to oxytocin, its enhanced expression can be involved in the oxytocin-induced B-TEC growth as well. Altogether, these data indicate that oxytocin contributes to cell motility and growth in HMEC and B-TEC.

Oxytocin during myomectomy: a randomized study

OBJECTIVE

To evaluate the influence of oxytocin on peroperative blood loss during myomectomy.

STUDY DESIGN

From October 1998 to May 2002, 94 patients requiring surgical myomectomy by laparotomy or by the vaginal approach were enrolled in a randomized double blind study. Patients were randomized to two groups. In the first group (47 patients) oxytocin was administered during myomectomy and in the second group (47 patients) a placebo was used. The main outcome measures were peroperative blood loss and rates of blood transfusion and autotransfusion.

RESULTS

Peroperative blood loss was no different between the oxytocin group and the placebo group (508 +/- 558 ml versus 451 +/- 336 ml; P=0.55). Rates of autotransfusion and blood transfusion were also similar in both groups.

CONCLUSION

Administration of oxytocin during myomectomy did not reduce peroperative blood loss in our study. The benefits of using oxytocin to prevent hemorrhage during myomectomy seem to be limited.