Different Doses Of Oxytocin Research Articles

Effects of Oxytocin on Glutamate Mediated Neurotoxicity in Neuroblastoma Cell Culture.

We aimed to investigate the effects of oxytocin on neurite growth, cell viability, cell proliferation and apoptosis to demonstrate its neuroprotective effect on glutamate induced neurotoxicity in human neuroblastoma SH-SY5Y cell culture. The effect of oxytocin on the toxic effects of glutamate in human neuroblastoma SH-SY5Y cell line with the Neurotoxicity Screening Test (NTT), apoptotic effects by Terminal Transferase dUTP Nick End Labeling (TUNEL) method and cell viability test by 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide (MTT) method. In the NTT test; Neurotoxicity was induced by adding glutamate at a concentration of 32 μM to the cell culture. Oxytocin was added at 1, 3, 10, 30 and 100 μM concentrations and its effect on neurite elongation was investigated. It was demonstrated by TUNEL method that application of glutamate caused apoptosis. Afterwards, when glutamate and different doses of oxytocin were given, antiapoptotic effect was evaluated with the apoptotic index. Glutamate was found to have a dose-dependent neurotoxic effect and reduced neurite elongation by 50% at a concentration of 32 μM. It was shown that the inhibition of neurite elongation caused by glutamate decreased in a dose-dependent manner by applying oxytocin. Especially oxytocin was found to significantly reduce neurite inhibition and show a neuroprotective effect starting from 10 μM concentrations. The concentration at which glutamate reduces cell proliferation by 50% was determined as 54 μM in MTT. Subsequently, it was observed that the adverse effect of glutamate on cell proliferation significantly decreased with oxytocin administration, depending on the dose. It was found that different concentrations of glutamate have a significant toxic effect on cell proliferation and viability, glutamate inhibits neurite elongation in a dose-dependent manner; oxytocin reduces neurite inhibition caused by glutamate, has a neuroprotective effect, increases cell viability and has antiapoptotic effects.

Effect of Oxytocin on the Body Weight of Male Rabbits

This study was carried out to investigate the effect of two different doses of oxytocin on weight. Adult male rabbits (15) were weighed and provided with food twice daily for 3 weeks to determine the amount of food consumed daily and the time spent feeding by each rabbit. After 3 weeks the rabbits were weighed and divided randomly into 3groups: the control group, the low dose group, and the high dose group. The animals were injected daily for 3 weeks. During that time the amount of food consumed and the time spent feeding in both periods were determined. After the end of the treatment period the rabbits were weighed, and sacrificed. The results of this study showed that before treatment the rabbits consumed more food in the evening period than they did in the afternoon period. The mean time spent feeding in the evening period was slightly higher than that spent in the afternoon period; however, this difference was not statistically significant. After treatment, there was still significant difference between the means of the consumed food in the afternoon and the evening period for the control group. The mean amounts of food consumed in both periods by the treated groups were slightly reduced, but this reduction was not statistically significant. Furthermore, the mean time spent feeding in the evening period was slightly higher than that of the afternoon period for the 3 groups; however, these differences were not significant. The mean weight of the control group was slightly increased after treatment with the hormone; and the mean weights of the treated groups were slightly reduced after treatment. However, changes in body weighs were not statistically significant.

Oxytocin Reduces Brain Injury and Maintains Blood-Brain Barrier Integrity After Ischemic Stroke in Mice.

The present study was designed to determine the effect of different doses of oxytocin (OXT) on neuronal injury, spatial memory, blood-brain barrier (BBB) integrity and to explore possible underlying molecular mechanisms in the early stage of stroke in mice. Stroke model was generated by middle cerebral artery occlusion (MCAO) for 60min and 24h reperfusion in mice. OXT at doses of 1, 2, 4 and 8IU/per mouse was administrated intranasally at the beginning of brain ischemia. Brain injury, BBB integrity, and spatial memory were evaluated by standard methods. Changes in the expressionof nuclear factor-kappa B (NF-κB), and TUNEL positive cell were detected by immunohistochemistry. The levels of vascular endothelial growth factor(VEGF), aquaporin-4 (AQP4) and brain-derived neurotrophic factor (BDNF) proteins were determined by western blotting and ELISA methods. OXT at doses of 4 and 8IU/per mouse reduced the infarct size by 42% and 52%, respectively, and improved spatial memory function (p < 0.001). OXT (8IU/per mouse) significantly reduced brain edema, BBB disruption and upregulated the AQP4 expression (p < 0.001). Finally, OXT significantly diminished the number of apoptotic, NF-κB positive cells and enhanced the expression of BDNF and VEGF proteins in the brain tissue (p < 0.001). These findings provide important evidences that OXT significantly suppresses neuronal damage in the early stage of stroke by inhibiting apoptotic and NF-κB signaling pathway, increasing the expression of VEGF, AQP4 and BDNF proteins and reducing the BBB leakage.

OXYTOCIN DOSE ANALYSIS OF BREASTMILK PRODUCTION THROUGH INDUCTION LABOR

Breast milk is the only first food that can be consumed by newborns until the age reaches six months. therefore it is very important to know by the mother who is pregnant and will give birth about the importance of breast milk. Oxytocin drugs have similar functions to the natural hormone oxytocin produced by the body. This drug serves to trigger or strengthen the contraction of the uterine muscle. Therefore, oxytocin can be used to stimulate (induce) labor and stop bleeding after childbirth. In addition, this drug can also help stimulate the release of breast milk in breastfeeding mothers. Oxytocin should be avoided by pregnant women who can not give birth normally, for example because it has a narrow pelvis, suffering from placenta previa, or having a too strong uterine contractions. Oxytocin is also prohibited for pregnant women with cephalopelvic disproportion, impaired fetal conditions, uterine damage, or a history of caesarean section. In this study we see whether there is effect of different doses of oxytocin on the quantity of breastmilk produced. oxytocin doses were administered with 3 doses of 5 UI, 10 UI and 15 UI. the dose of oxytocin is administered once per incidence of labor. maternal results obtained by oxytocin induction of 5 UI and 10 UI obtained breastmilk averaging 10 ml in the first 24 hours after delivery. and a mother with oxytocin induction 15 UI received an average breastmilk of 10 ml at 24 hours after delivery.

Effect of Intranasal Oxytocin Administration on Human-Directed Social Behaviors in Shelter and Pet Dogs.

A wide variety of evidence has demonstrated that oxytocin is involved in socio-cognitive skills in domestic dogs (Canis familiaris). The purpose was to evaluate the effect of oxytocin administration on socio-cognitive abilities in two populations of dogs with different levels of daily human contact: shelter and pet dogs. Additionally, the effect of different doses of oxytocin (i.e., 16 and 24 IU) was assessed. To this end, dogs were tested on two tasks: a sociability test to assess their social responses and a communicative task focused on the learning of gazing responses. Results showed that pet dogs performed better than shelter dogs on the sociability and the gazing tests showing the relevance of dogs’ previous experience and learning when interacting with people. The administration of 16 IU as well as 24 IU of oxytocin improved the performance on the communicative learning task, producing an increment in gaze duration during extinction. This difference was observed in both pet and shelter dogs. Therefore, oxytocin seems to participate in the persistence of this communicative response. However, the treatment did not modify the behaviors during the sociability test. Furthermore, oxytocin appears to be beneficial to increase the communicative abilities of shelter dogs.

Effect of different doses of oxytocin on cardiac electrophysiology and arrhythmias induced by ischemia.

The onset of acute myocardial ischemia (MI) is accompanied by a rapid increase in electrical instability and often fatal ventricular arrhythmias. This study investigated that whether oxytocin (OT) can modulate ischemia-induced arrhythmias and considered relationships between the severity of arrhythmia and the electrocardiogram parameters during ischemia. OT (0.0001–1 μg) was administrated intraperitoneally 30 min before ischemia. To examine receptor involved, a selective OT-receptor antagonist, atosiban (ATO), was infused 10 min before OT. OT caused a significant and biphasic dose-dependent reduction in ectopic heart activity and arrhythmia score. OT doses that reduced ventricular arrhythmia elicited significant increase in QT interval. OT attenuated the electrophysiological changes associated with MI and there was significant direct relationship between QRS duration and arrhythmia score. ATO treatment reduced beneficial effects of OT on arrhythmogenesis. Nevertheless, ATO failed to alter OT effects on premature ventricular contractions. We assume that the ability of OT to modulate the electrical activity of the heart may play an important role in the antiarrhythmic actions of OT.

Protective effects of oxytocin on maternal aggression in stress model rats

Objective To explore the effect of the different doses of oxytocin(OXT) on stress model aggressive behaviour in Wistar rats. Methods According to random number table, 40 pregnant rats were divided into experimental stress groups (A, B, C) and control group(D) with 10 samples in each group.Before forced swimming test, rats in experimental groups(A, B, C)were given OXT via intraperitoneal injection with 0.3 mg/kg, 1.0 mg/kg, 2.0 mg/kg; rats in group D were given equal volume of normal saline in the same way. At the 3rd day all rats were tested with maternal aggression, including mothers' following indices as total aggression times, biting times, pinning times, attack latency and duration of attack.Elevated plus maze(EPM) test was applied to analyze the behavioral changes. Results In terms of the duration of attack and attack latency, the indexes of group A and group D were significantly different from relevant data ((147.60±23.92 )s and(79.70±9.88)s, P 0.05). The duration of attack and attack latency had a significant difference ((3.10±0.87)times, (13.60±5.14)times, (91.30±9.74)s and(167.20±30.02)s, P 0.05). Group C and group D in given indexes had significant differences showing (6.40±1.34)times, (15.10±4.35)times, (23.70±3.46)times, (49.80±5.53)s and(215.60±39.55)s(P 0.05). In EPM, the open arm entry ratio and the open arm time ratio of both group A and group D were significantly different from respective percentage (0.47±0.13) and (0.13±0.05)(P 0.05). Conclusion Oxytocin potentially mediates maternal aggression by attenuating stress, and improves the intimate bonding between mother and pups, which means dose dependency of OXT in this process. Key words: Stress model; Anxiety; Oxytocin; Maternal aggression; Elevated plus maze(EPM)

Effect of different doses of oxytocin on milk production of bovine females

Effect of different doses of oxytocin on milk production of bovine females

Divergent effects of oxytocin treatment of obese diabetic mice on adiposity and diabetes.

Oxytocin has been suggested as a novel therapeutic against obesity, because it induces weight loss and improves glucose tolerance in diet-induced obese rodents. A recent clinical pilot study confirmed the oxytocin-induced weight-reducing effect in obese nondiabetic subjects. Nevertheless, the mechanisms involved and the impact on the main comorbidity associated with obesity, type 2 diabetes, are unknown. Lean and ob/ob mice (model of obesity, hyperinsulinemia, and diabetes) were treated for 2 weeks with different doses of oxytocin, analogues with longer half-life (carbetocin) or higher oxytocin receptor specificity ([Thr4,Gly7]-oxytocin). Food and water intake, body weight, and glycemia were measured daily. Glucose, insulin, and pyruvate tolerance, body composition, several hormones, metabolites, gene expression, as well as enzyme activities were determined. Although no effect of oxytocin on the main parameters was observed in lean mice, the treatment dose-dependently reduced food intake and body weight gain in ob/ob animals. Carbetocin behaved similarly to oxytocin, whereas [Thr4,Gly7]-oxytocin (TGOT) and a low oxytocin dose decreased body weight gain without affecting food intake. The body weight gain-reducing effect was limited to the fat mass only, with decreased lipid uptake, lipogenesis, and inflammation, combined with increased futile cycling in abdominal adipose tissue. Surprisingly, oxytocin treatment of ob/ob mice was accompanied by a worsening of basal glycemia and glucose tolerance, likely due to increased corticosterone levels and stimulation of hepatic gluconeogenesis. These results impose careful selection of the conditions in which oxytocin treatment should be beneficial for obesity and its comorbidities, and their relevance for human pathology needs to be determined.

Epidural Use and Clinical Chorioamnionitis among Women Who Delivered Vaginally

Chorioamnionitis, an important cause of maternal and neonatal morbidity, is influenced by epidural use and the occurrence of epidural fever. We evaluated the association between chorioamnionitis, histologic placental findings, and intrapartum factors focusing on epidural use. We conducted a secondary analysis of a randomized controlled trial of different doses of oxytocin to prevent postpartum hemorrhage among women who delivered vaginally. The primary outcome was clinical diagnosis of chorioamnionitis leading to antibiotic therapy. Intrapartum factors examined included epidural use, parity, labor induction, gestational age, maternal age, ethnicity, body mass index, cervical dilatation at admission, preeclampsia/eclampsia, preterm labor, and duration of labor. Of the 1,798 women randomized, we excluded 13 multifetal births leaving 1,785 for analysis: 1,491 had an epidural and 294 did not. Of those with epidural, 8.0% had clinically diagnosed chorioamnionitis compared with only 1.0% without epidural: unadjusted odds ratio (OR) = 8.3 (95% confidence interval [CI]: 2.63-26.40); p < 0.0001. After multivariable logistic regression, epidural use (adjusted OR: 5.80; 95% CI: 1.77-19.11), increasing parity (0.42; 0.32-0.55), and preeclampsia (0.31; 0.14-0.66) were significantly associated with chorioamnionitis. Epidural use is statistically associated with an increase in clinical diagnosis of chorioamnionitis. A cause and effect relationship cannot be confirmed from this study. Independently of labor duration and increasing parity, preeclampsia appeared protective.

The Functional Role of Oxytocin in the Induction of Oocyte Meiotic Resumption in Cattle

The aim of the present study was to examine the role of oxytocin (OT) in the progesterone (P4) and prostaglandins (PGs) pathway to induce oocyte meiotic resumption. Cumulus-oocyte complexes were co-cultured with follicular hemisections for 15h to determine the effects of different doses of OT or atosiban (ATO; oxytocin receptor antagonist) on oocyte meiotic resumption. In another experiment, we examined the effect of the interaction between P4, OT and PGs on the regulatory cascade of the oocyte meiotic resumption. Oxytocin at 1μm was effective in inducing meiotic resumption in oocytes co-cultured with follicular cells (84.0%), not differing from the positive control group (74.4%). Atosiban inhibited in a dose-dependent manner the positive effect of OT on the meiotic resumption (27.6% metaphase I with 10μm of ATO, which did not differ from the 25.5% of the negative control group). Furthermore, a third experiment showed that P4 was able to induce oocyte meiotic resumption, which was inhibited by ATO. However, the OT positive effect was not blocked by mifepristone (P4 antagonist), but was inhibited by indomethacin (a non-selective PTGS2 inhibitor). Collectively, these data suggest a sequential role of P4, OT and PGs in the induction of oocyte meiotic resumption.

Estudio clínico y farmacoeconómico de la eficacia de la carbetocina en cesáreas electivas respecto a la oxitocina a dosis bajas y a dosis habituales

ObjectivesTo evaluate uterine contractility, bleeding, haemodynamic performance, and side effects of different doses of oxytocin after delivery under spinal anaesthesia in caesarean section without prior labour in childbirth. We also perform a pharmacoeconomic evaluation. Material and methodsA randomised, descriptive, observational and multicentre prospective study was conducted, which included 104 ASA 1 patients divided into 3 groups. Group 1 (n=52) received after removal of the foetus and coinciding with foetal umbilical cord clamping, 1 IU of oxytocin followed by an infusion of 2.5 UI×h−1; Group 2 (n=52) a continuous infusion of 20IU oxytocin at a rate of 700mUI×min−1 followed later by 10UI×h−1, and group 3, 100μg bolus dose of carbetocin only. ResultsThere were no statistical differences between groups in anthropometric, obstetric or anaesthetic variables. Significant differences in uterine contraction in vaginal bleeding and the incidence of side effects, particularly headache and tremor, were more pronounced in the carbetocin group. ConclusionsWith these results, we cannot recommend the routine use of carbetocin in caesarean sections, because it is accompanied by an increased incidence of side effects without any improvement in the prevention of obstetric haemorrhage. Finally, it is economically more expensive than the use of low doses of oxytocin, which may be the trend that should be considered in the future, due to the clinical outcomes, and its lower cost.

Divergent effects of two different doses of intranasal oxytocin on facial affect discrimination in schizophrenic patients with and without polydipsia

Hyponatremia and dexamethasone resistance in polydipsic schizophrenic patients are attributable to changes in hippocampal-modulated antidiuretic and stress hormone activity, respectively. The relationship of the neuroendocrine findings to the psychiatric illness, however, is unknown. An impaired ability to identify facial emotions has been linked to core features of schizophrenia and to diminished levels of the closely related hormone, oxytocin, in the polydipsic subset. Intranasal oxytocin enhances facial affect discrimination in healthy subjects. The aim of this study is to explore if oxytocin reverses impaired facial affect discrimination in schizophrenic patients with, relative to that in patients without, polydipsia. Intranasal oxytocin (10 or 20 IU) and placebo were administered on three occasions to five polydipsic schizophrenic patients, eight nonpolydipsic patients, and 11 healthy controls. Subsequently, subjects rated the presence and intensity of six facial emotions. Emotion recognition fell in both patient groups following 10 IU of oxytocin due to an increased propensity to identify all emotions regardless of whether they were displayed. By contrast, emotion recognition improved following 20 IU in polydipsic relative to nonpolydipsic patients due primarily to divergent effects on the bias to identify fear in nonfearful faces. The effects of 20 IU oxytocin support the hypothesis that altered neuroendocrine function in polydipsic patients contributes to their psychiatric illness. Further studies are warranted to confirm these findings and assess if oxytocin treatment improves social functioning in this subset. This is the first psychopharmacologic study to compare different doses of oxytocin in the same subject, thus the significance of the opposing responses is unclear.

Eficacia de la oxitocina a dosis bajas en cesáreas electivas

Background and objectiveIn cesarean section, the optimal dose of oxytocin to reduce the risk of hemorrhage with the least risk of adverse effects has yet to be defined. We studied the effects of using 2 different doses of oxytocin in women undergoing elective cesarean section under spinal anesthesia. The women had had no prior labor. Material and methodsRandomized multicenter trial enrolling 104 patients classified as ASA 1. Following fetal extraction and coinciding with umbilical cord clamping, a group of 52 women received 1IU of oxytocin followed by an infusion of 2.5IU·h-1; a second group of 52 women received a continuous infusion of 20IU at a rate of 700mIU·min-1followed by 10IU·min-1. We compared uterine contractility (assessed as absent, moderate, satisfactory), postoperative vaginal bleeding (absent, light, moderate, heavy), hemodynamics, and adverse effects after administration of oxytocin and fetal extraction (electrocardiographic abnormalities, nausea, vomiting, discomfort, headache, blushing, trembling, chills, or chest pain). ResultsNo significant between-group differences in patient, obstetric, or anesthetic variables were detected. Uterine contraction was satisfactory in over 90% of the patients in both groups on initial assessment during surgery. After surgery, vaginal bleeding was absent or light in over 90% of the women. No significant differences in adverse events were detected between groups. ConclusionsThe incidence of obstetric bleeding is not higher when a lower dose of oxytocin is used; the rate of postoperative adverse events also does not increase.

Evaluation of the efficacy of three different doses of oxytocin on uterine fluid clearance in mares

Evaluation of the efficacy of three different doses of oxytocin on uterine fluid clearance in mares

ST depression at caesarean section and the relation to oxytocin dose. A randomised controlled trial

To investigate whether there is a difference in occurrence of electrocardiogram changes suggestive of myocardial ischaemia between two different doses of oxytocin. Double-blind randomised controlled trial. University hospital in Sweden. A total of 103 healthy women undergoing elective caesarean section under spinal anaesthesia. The participants were randomised to 5 or 10 units of oxytocin, given as an intravenous bolus. A Holter monitor was used to record electrocardiograms and non invasive blood pressure and heart rate (HR) was monitored. A blood sample was obtained 12-hour postoperatively. Depression of the ST segment. symptoms, Troponon I levels, mean arterial pressure (MAP), HR and blood loss. There was a significant difference in occurrence of ST depressions associated with oxytocin administration, 4 (7.7%) with 5 and 11 (21.6%) with 10 units, P < 0.05. The absolute risk reduction was 13.9% (95% confidence interval, 0.5-27.3). Decrease of mean MAP from baseline to 2 minutes differed, being 9 mmHg in the 5 unit group and 17 mmHg in the 10 unit group (P < 0.01). The increase in mean HR did not differ. Troponin I levels were increased in four subjects (3.9%). There were no differences in occurrence of symptoms, Troponin I levels, or estimated blood loss. ST depressions were associated with oxytocin administration significantly more often in subjects receiving 10 units compared with 5 units. Interventions to prevent hypotension during caesarean section may reduce the occurrence of ST depressions on electrocardiograms.

Effect of Different Doses of Oxytocin at Delivery on Suffering and Survival of Newborn Pigs

Effect of Different Doses of Oxytocin at Delivery on Suffering and Survival of Newborn Pigs

The effects of oxytocin on the activity of cells in the anterior hypothalamus in experimental stress

Acute experiments on white laboratory rats were performed to study spike activity in neurons of the anterior hypothalamus in response to i.v. injections of different doses of oxytocin. The results showed that oxytocin evoked different types of rearrangement of neuron activity both in intact and in stressed animals. The dose-related effects of oxytocin affected the latent periods of neuron responses and the nature of rearrangements in spike activity. The greater the frequency of the baseline activity of the cells, the less marked was the response of the neurons to administration of oxytocin.

Prolonged progesterone treatment of endometrial epithelial cells modifies the effect of estradiol on their sensitivity to oxytocin

Estradiol (E2), progesterone (P4), and oxytocin (OT) are important for the initiation of luteolysis in ruminants but the mechanisms involved are still poorly understood. The objective of this study was to determine if duration of exposure of bovine endometrial epithelial cells to P4 affected the response of the cells to E2. Endometrial epithelial cells, from cows at Days 1–3 of the estrous cycle, were cultured for 10, 17, and 21 days in the presence or absence of P4 (100 ng ml −1). After culture, each group of cells was incubated for a further 6, 12, 24 or 48 h with or without E2 (100 pg ml −1) and then incubated for 6 h with different doses of OT (2, 20, and 200 ng ml −1). E2 enhanced OT-stimulated PGF2α secretion in cells cultured with P4 for 17 or 21 days, with a maximum effect after 24-h exposure, but not in cells cultured with P4 for 10 days. To determine the mechanism of action of E2, COX-1 and COX-2 were measured by Western blotting and OTR number was measured by saturation analysis. OT increased COX-2 ( P<0.05), but there was no significant effect of E2 on the expression of either COX-1 or COX-2. E2 did, however, increase ( P<0.001) the OTR number in cells cultured with P4 for 21 days, whereas it inhibited OTR in cells cultured for 10 days. These data show that E2 can stimulate PGF2α secretion by increasing OTR expression in bovine endometrial cells in vitro, but only after exposure to P4.

Uterine secretion of prostaglandin F2alpha stimulated by different doses of oxytocin and released spontaneously during luteolysis in cattle.

The objectives were to determine the involvement of oxytocin (OT) in the stimulation of prostaglandin F2alpha (PGF) secretion during luteolysis in cattle. On days 16-17 of the oestrous cycle, catheters were inserted into the aorta abdominalis of heifers for OT or saline infusion and into the jugular vein for blood sample collection. The following day, heifers were assigned to one of three experimental groups (Gr): Gr I - 10 IU OT (n=4); Gr II - 20 IU OT (n=4); Gr III - 50 IU OT (n=4). Blood samples were collected every 10 min during a 1-h control period before treatment and every 5-10 min for 2 h after OT treatment. In Gr IV (n=5), a catheter was inserted into the jugular vein on day 15 of the cycle and blood samples were collected every 15 min for 12 h on days 16-19. Plasma concentrations of progesterone, PGF metabolite, 13, 14-dihydro-15-keto-prostaglandin F2alpha (PGFM) and OT were determined. Within 5 min of infusion of 10 or 20 IU OT, peripheral concentrations of OT (7-12 pg/mL) increased by about 200 and 350-500 pg/mL, respectively. These doses did not affect plasma concentrations of PGFM or progesterone within 1.5 h. Fifty IU of OT increased its maximal peripheral concentration to 1500 pg/mL, which is over 20 times greater than that observed physiologically. Concentrations of plasma PGFM in Gr III increased from basal concentrations (5065 pg/mL) to 150-250 pg/mL (P < 0.01) within 10-30 min. During luteolysis, PGFM pulses ranged between 250 and 600 pg/mL on days 16-19 of the cycle (Gr IV), whereas coincident pulses of OT, and those appearing between spikes of PGFM, were never above 75 pg/mL. Only 50% of OT pulses coincided with pulses of PGFM, and 54 % of PGFM pulses coincided with a pulse of OT. Results indicate that luteolytic PGF secretion in cattle is not directly dependent upon ovarian OT.