Effects Of Oxytocin Administration Research Articles

The effect of Oxytocin administration on patient-therapist alliance congruence: Results from a randomized controlled trial

Objectives The effects of oxytocin (OT) administration on psychotherapeutic processes have thus far been elusive. This study explored the effect of OT administration on patient-therapist congruence of the working alliance. Method Inpatients with mental disorders (N = 87) participating in a randomized controlled trial received OT (n = 44) or placebo (n = 43) intranasally twice a day, for four weeks. Patients and therapists rated the alliance after each session. Results Oxytocin significantly moderated the level of agreement (b = −0.56, SE = 0.25, t = −2.30, p = 0.02), such that patients receiving OT demonstrated lower discrepancy (b = −0.73, p < 0.001) than did those receiving placebo (b = −1.30, p < 0.001). On the other hand, the mutual covariance of patient-therapist ratings across sessions was positive and significant for patients receiving placebo (b = 0.26, p = 0.01) but not for patients in the OT group (b = −0.06, p = .56). Conclusion Oxytocin can reduce discrepancies of patient-therapist perceptions of the alliance, although additional studies are needed to explore OT's effect on alliance development over time. As alliance congruence is associated with therapy outcomes, such intervention may lead to enhancement of therapeutic gains.

A double-edged hormone: The moderating role of personality and attachment on oxytocin's treatment facilitation effect

BackgroundStudies exploring the potential augmenting effect of oxytocin for patients with mental disorders have thus far reported mixed effects. However, oxytocin’s effect may differ across patients with different interpersonal characteristics. This study aimed to examine the moderating role of attachment and personality traits on the effect of oxytocin administration on the therapeutic working alliance and symptomatic change, among hospitalized patients with severe mental illness. MethodsPatients (N = 87) were randomly assigned to receive oxytocin or placebo, as an add-on to psychotherapy for a period of four weeks, in two inpatient units. Therapeutic alliance and symptomatic change were measured weekly, and personality and attachment were assessed at pre- and post-intervention. ResultsOxytocin administration was significantly associated with improvement of depression (B=2.12, SE=0.82, t = 2.56, p = .012), and suicidal ideation (B=0.03, SE=0.01, t = 2.44, p = .016) for patients low in openness and extraversion, respectively. Nonetheless, oxytocin administration was also significantly associated with a deterioration in the working alliance for patients high in extraversion (B=−0.11, SE=0.04, t = −2.73, p = .007), low in neuroticism (B=0.08, SE=0.03, t = 2.01, p = .047) and low in agreeableness (B=0.11, SE=0.04, t = 2.76, p = .007). ConclusionsOxytocin may act as a double-edged sword when it comes to its effect on treatment process and outcome. Future studies should focus on routes to characterize patients who might benefit the most from such augmentation. Clinical trial registrationPre-registration in clinicaltrials.com: NCT03566069; Israel Ministry of Health: MOH_2017–12–05_002003.

Effects of oxytocin administration on fear-potentiated acoustic startle in co-occurring PTSD and alcohol use disorder: A randomized clinical trial

Co-occurring posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) is common and particularly associated with elevation of hyperarousal compared to PTSD alone. Treatment options are limited. Oxytocin regulates physiological stress response. Intranasal oxytocin administration has demonstrated potential in reducing symptoms of both PTSD and AUD. This study addresses a gap in the literature by investigating effects of intranasal oxytocin on startle reactivity, an important potential marker of both PTSD and AUD symptomatology. This is a randomized, double-blind, placebo-controlled, within- and between-participant, crossover, dose-ranging study examining the effects of a single administration of oxytocin 20 IU versus 40 IU versus placebo on psychophysiological responses to a common laboratory fear-potentiated acoustic startle paradigm in participants with PTSD-AUD (n = 47) and controls (n = 37) under three different levels of threat. Contrary to our hypothesis, for the PTSD-AUD group, oxytocin 20 IU had no effect on startle reactivity, while oxytocin 40 IU increased measures of startle reactivity. Additionally, for PTSD-AUD only, ambiguous versus low threat was associated with an elevated skin conductance response. For controls only, oxytocin 20 IU versus placebo was associated with reduced startle reactivity.

Effects of oxytocin administration on salivary sex hormone levels in autistic and neurotypical women

Effects of oxytocin administration on salivary sex hormone levels in autistic and neurotypical women

Autonomic Responses during Labor: Potential Implications for Takotsubo Syndrome

Takotsubo syndrome is a serious complication of labor. Although the pathophysiologic role of excessive sympathetic activation is established in this process, concurrent vagal responses have not been adequately described. Moreover, it remains unclear whether autonomic activity depends on the mode of delivery. Here, we explored the hypothesis that the different management of cesarean and vaginal delivery may elicit diverse responses affecting both autonomic arms. For this aim, continuous electrocardiographic recording was performed in 20 women during labor, and non-invasive indices of sympathetic and vagal activity were compared between the two modes of delivery. We report sympathetic prevalence during cesarean delivery, caused by marked vagal withdrawal, whereas autonomic activity was rather stable during vaginal delivery. These differences may be attributed to the effects of anesthesia during cesarean delivery, along with the protective effects of oxytocin administration during vaginal delivery. Our results provide further insights on autonomic responses during labor that may prove useful in the prevention of complications, such as takotsubo syndrome.

Oxytocin ameliorates impaired social behavior in a Chd8 haploinsufficiency mouse model of autism

BackgroundAutism spectrum disorder (ASD) is characterized by the core symptoms of impaired social interactions. Increasing evidence suggests that ASD has a strong genetic link with mutations in chromodomain helicase DNA binding protein 8 (CHD8), a gene encoding a chromatin remodeler. It has previously been shown that Chd8 haplodeficient male mice manifest ASD-like behavioral characteristics such as anxiety and altered social behavior. Along with that, oxytocin (OT) is one of the main neuropeptides involved in social behavior. Administration of OT has shown improvement of social behavior in genetic animal models of ASD. The present study was undertaken to further explore behavioral abnormalities of Chd8 haplodeficient mice of both sexes, their link with OT, and possible effects of OT administration. First, we performed a battery of behavioral tests on wild-type and Chd8+/∆SL female and male mice. Next, we measured plasma OT levels and finally studied the effects of intraperitoneal OT injection on observed behavioral deficits.ResultsWe showed general anxiety phenotype in Chd8+/∆SL mice regardless of sex, the depressive phenotype in Chd8+/∆SL female mice only and bidirectional social deficit in female and male mice. We observed decreased level of OT in Chd+/∆SL mice, possibly driven by males. Mice injected by OT demonstrated recovery of social behavior, while reduced anxiety was observed only in male mice.ConclusionsHere, we demonstrated that abnormal social behaviors were observed in both male and female Chd8+/∆SL mice. The ability of peripheral OT administration to affect such behaviors along with altered plasma OT levels indicated a possible link between Chd8 + /∆SL and OT in the pathogenesis of ASD as well as the possible usefulness of OT as a therapeutic tool for ASD patients with CHD8 mutations.

Effects of oxytocin administration and the dog-owner bond on dogs' rescue behavior.

Rescue behavior is a kind of prosocial response that involves the provision of help to a stressed individual. This behavior has been observed in domestic dogs assisting their owners when they pretended to be trapped. Given the role of the hormone oxytocin as a facilitator for prosocial behavior, we aimed to evaluate the effects of its intranasal administration on the rescue behavior of dogs directed to their owners. In addition, we used the Monash Dog Owner Relationship Scale (MDORS) to assess whether the dog-owner bond was associated with this behavior. After receiving either oxytocin or saline, dogs participated in a stressed condition in which their owner pretended to be stressed inside of a box, or a control one, in which the owner was in a calm state. Dogs released their owners more frequently in the stressed condition. Contrary to our expectations, dogs who received oxytocin were less likely to open the box and took longer to do so than those that received saline. Regarding the dog-owner bond, dogs in the stressed condition who received oxytocin exhibited a lower rate and a higher latency of openings the more intense the bond was, while the opposite pattern was observed in dogs in the control condition who received saline. In conclusion, dogs would rescue their owners when they pretended to be trapped and stressed. Both oxytocin administration and the bond with the owner appear to modulate this behavior, but further studies are needed to inquire into the involved mechanisms.

Effects of Oxytocin Administration on Doppler Indices of Mammary Artery in Postpartum Ewes

Dogum sonrasi uterus involusyonunu hizlandirmak ve sutun indirilmesini saglamak amaciyla siklikla uygulanan oksitosin hormonu vaskuler tonusun duzenlenmesinde de etkilidir. Doppler ultrasonografi, doku ve organlara ait kan akimi ozelliklerinin degerlendirilebilmesine olanak saglayan oldukca pratik bir tekniktir. Bu calismada postpartum donemdeki koyunlara uygulanan oksitosin hormonunun meme kan akiminda olusturdugu hemodinamik degisikliklerin incelenmesi amaclandi. Calisma tekiz kuzulamis olan 20 adet primipar Kivircik irki koyun ile gerceklestirildi. Koyunlar randomize sekilde oksitosin ve kontrol gruplarina ayrildi (her grup icin n=10). Oksitosin ve kontrol gruplarina sirasiyla 10 IU/koyun dozda oksitosin ve 1 ml/koyun dozda serum fizyolojik dogum sonrasi ilk uc gun boyunca gunde 2 kez kas ici yoldan uygulandi. Puls Doppler ultrasonografi teknigi kullanilarak eksternal pudendal artere ait pulsatilite ve rezistans indeksleri (sirasiyla PI ve RI) olculdu. Oksitosin grubu daha yuksek PI ve RI degerlerine sahip olma egiliminde olmasina karsin gruplar arasinda anlamli farklilik sadece birinci ve ikinci postpartum gunlerin PI degerlerinde saptandi (sirasiyla p<0,001 ve p<0,05). Postpartum erken donemdeki koyunlara uygulanan oksitosin hormonunun, meme arterinin direncini arttirdigi sonucuna ulasildi.

The effect of oxytocin on pupil response to naturalistic dynamic facial expressions

The neuropeptide oxytocin (OT) has been found to play an important role in a variety of social behaviours and social cognition in particular. The social salience hypothesis of OT suggests that OT shifts attention towards socially relevant stimuli, which offers an explanation for improvements on social cognition measures following OT administration. Pupil dilation occurs with increasing attentional resource allocation and previous research has found that OT administration led to an increase in pupil diameter in response to social stimuli relative to placebo (PL), thereby suggesting increased social attention. The current study aimed to investigate the effects of OT on pupillary responses to more naturalistic social stimuli in a larger sample. Ninety-four male participants took part in the double-blind, placebo controlled, mixed-design study, in which they self-administered either an OT or PL nasal spray before viewing naturalistic dynamic facial expressions of emotion (happy, sad, fear and anger). Contrary to prediction, there was no effect of OT administration on pupil diameter. The results are discussed in light of the social salience hypothesis and with reference to the methodological differences between studies.

Effects of oxytocin administration and conditioned oxytocin on brain activity: An fMRI study.

It has been demonstrated that secretion of several hormones can be classically conditioned, however, the underlying brain responses of such conditioning have never been investigated before. In this study we aimed to investigate how oxytocin administration and classically conditioned oxytocin influence brain responses. In total, 88 females were allocated to one of three groups: oxytocin administration, conditioned oxytocin, or placebo, and underwent an experiment consisting of three acquisition and three evocation days. Participants in the conditioned group received 24 IU of oxytocin together with a conditioned stimulus (CS) during three acquisition days and placebo with the CS on three evocation days. The oxytocin administration group received 24 IU of oxytocin and the placebo group received placebo during all days. On the last evocation day, fMRI scanning was performed for all participants during three tasks previously shown to be affected by oxytocin: presentation of emotional faces, crying baby sounds and heat pain. Region of interest analysis revealed that there was significantly lower activation in the right amygdala and in two clusters in the left superior temporal gyrus in the oxytocin administration group compared to the placebo group in response to observing fearful faces. The activation in the conditioned oxytocin group was in between the other two groups for these clusters but did not significantly differ from either group. No group differences were found in the other tasks. Preliminary evidence was found for brain activation of a conditioned oxytocin response; however, despite this trend in the expected direction, the conditioned group did not significantly differ from other groups. Future research should, therefore, investigate the optimal timing of conditioned endocrine responses and study whether the findings generalize to other hormones as well.

Effects of oxytocin administration on salivary sex hormone levels in autistic and neurotypical women

BackgroundOxytocin administration, which may be of therapeutic value for individuals with social difficulties, is likely to affect endogenous levels of other socially relevant hormones. However, to date, the effects of oxytocin administration on endogenous hormones have only been examined in neurotypical individuals. The need to consider multi-hormone interactions is particularly warranted in oxytocin trials for autism due to evidence of irregularities in both oxytocin and sex steroid systems.MethodsIn this double-blind cross-over study, saliva samples were collected from 16 autistic and 29 neurotypical women before and after intranasal administration of 24 IU oxytocin or placebo. Oestradiol, testosterone, and oxytocin levels were quantified in saliva samples. Participants also completed the Autism-Spectrum Quotient (AQ) and Empathy Quotient (EQ) questionnaires.ResultsDistinct patterns of change in testosterone and oestradiol levels pre- to-post-administration were observed in autistic relative to neurotypical women (ANCOVA, p < 0.05 main effect of Group), controlling for sample collection time. The mean percent change oestradiol was + 8.8% for the autism group and − 13.0% for the neurotypical group (t = 1.81, p = 0.08), while the mean percent change testosterone was + 1.1% in the autism group and − 12.6% in the neurotypical group (t = 1.26, p = 0.22). In the oxytocin condition, the mean percent change oestradiol was + 12.6% in the autism group and − 6.9% in the neurotypical group (t = 1.78, p = 0.08), while the mean percent change testosterone was + 14.4% in the autism group and − 15.2% in the neurotypical group (t = 3.00, p = 0.006). Robust regression confirmed that group differences in percent change hormone levels were not driven by a small number of influential individuals. Baseline hormone levels did not differ between groups when considered individually. However, baseline testosterone relative to oestradiol (T:E2 ratio) was higher in autistic women (p = 0.023, Cohen’s d = 0.63), and this ratio correlated positively and negatively with AQ and EQ scores, respectively, in the combined sample.LimitationsFurther studies with larger and more diverse autistic sample are warranted to confirm these effects.ConclusionsThis study provides the first evidence that oxytocin influences endogenous testosterone levels in autistic individuals, with autistic women showing increases similar to previous reports of neurotypical men. These findings highlight the need to consider sex steroid hormones as a variable in future oxytocin trials.

Effects of intranasal oxytocin administration on empathy and approach motivation in women with borderline personality disorder: a randomized controlled trial

Borderline personality disorder (BPD) is characterized by severe interpersonal dysfunction with problems in social cognition, empathy and social approach. Although the neuropeptide oxytocin is known to regulate complex social cognition and behavior in healthy individuals and clinical populations, there is still a lack of evidence for a potential beneficial effect of oxytocin administration on social cognition and social approach in BPD. Fifty-one women with BPD and 51 matched healthy controls were randomized to a double-blind, placebo-controlled, between-subject experimental trial. We administered a single dose of 24 IU oxytocin or placebo intranasally prior to a standardized task measuring affective and cognitive empathy and approach motivation. All participants were free of hormonal contraception and tested in the mid-luteal phase of their menstrual cycle. In the placebo condition, patients with BPD showed reduced cognitive and affective empathy, and less approach behavior motivation than healthy controls. Intranasal oxytocin significantly increased affective empathy and approach motivation in both BPD patients and healthy controls compared to placebo. More importantly, oxytocin administration led to similar scores between BPD and healthy controls. These findings provide the first evidence for a beneficial effect of oxytocin on deficits in affective empathy and approach motivation of BPD. Our results indicate a beneficial effect of a single dose of oxytocin on affective empathy and approach motivation in women with BPD adapting their level of social functioning to healthy controls. Future clinical trials will need to investigate the long-term effects and effectiveness of oxytocin as an add-on treatment for social impairments in BPD.

Effects of Oxytocin Administration on Cue-Induced Craving in Co-occurring Alcohol Use Disorder and PTSD: A Within-Participant Randomized Clinical Trial.

Individuals with alcohol use disorder (AUD) are much more likely to meet criteria for posttraumatic stress disorder (PTSD) than the general population. Compared to AUD alone, those with comorbid AUD-PTSD experience worse outcomes. Prior literature suggests that oxytocin, a hypothalamic neuropeptide, may be effective in the treatment of both AUD and PTSD when administered intranasally, although specific mechanisms remain elusive. Forty-seven male patients with comorbid AUD-PTSD were administered intranasal oxytocin in a randomized, double-blind, dose-ranging (20IU, 40IU, and matched placebo), within-participant design with study visits at least 1week apart. A cue-induced craving paradigm was conducted using each participant's preferred alcoholic beverage versus a neutral water cue. Self-reported alcohol craving and heart rate (HR) were recorded and analyzed using linear mixed-effect models. While alcohol cues significantly induced self-reported craving and increased HR compared to neutral water cues, neither dosage of oxytocin compared to placebo reduced self-reported cue-induced alcohol craving nor cue-induced changes in HR in patients with PTSD-AUD. These preliminary findings suggest that oxytocin does not affect cue-induced craving. Our results contribute to an ever-growing field of research investigating the effects of intranasal oxytocin on the symptoms of substance use disorders and will help further refine methodology and streamline future inquiries in this area.

Effects of oxytocin administration on milk yield and milk composition of West African Dwarf does

Abstract Incomplete evacuation of milk from the alveoli during milking leads to reduced milk yield and milk quality. This makes it imperative to search for means of enhancing complete removal of milk from the udder. The study was carried out to determine the effects of oxytocin (OT) administration on milk yield and milk composition of twenty one lactating West African Dwarf (WAD) does. The 21 does were grouped into three treatment groups of seven animals each, homogeneous by weight and parity, and fed 0.3–0.5 kg and 1 kg/head/day concentrate and Panicum maximum respectively and they have free access to water until the end of the experiment. Does were administered oxytocin intramuscularly for 12 weeks according to the dose assigned to each group: 0, 2, and 4 IU respectively. The experiment commenced five days post-partum. Does were injected with 1 IU synthetic oxytocin in the evening (7:00 pm) of weekly separation from their kids and hand milked to empty their udders. After 12 h of separation, the does were injected with the appropriate dose of oxytocin and hand milked. Weekly data were collected on milk yield, fat, protein, lactose, total solids, moisture, ash, solids-not-fat, milk pH and titratable acidity. Data were subjected to Analysis of Variance using the General Linear Model for repeated measures in Analytical Computer Package, Version 5.02 (SYSTAT, 1992). Milk yield was significantly (P

Effects of oxytocin administration on the hydromineral balance of median eminence-lesioned rats.

In the clinical setting, acute injuries in hypothalamic mediobasal regions, along with polydipsia and polyuria, have been observed in patients with cerebral salt wasting (CSW). CSW is also characterised by hypovolaemia and hyponatraemia as a result of an early increase in natriuretic peptide activity. Salt and additional amounts of fluid are the main treatment for this disorder. Similarly, experimental lesions to these brain regions, which include the median eminence (ME), produce a well-documented neurological model of polydipsia and polyuria in rats, which is preceded by an early sodium excretion of unknown cause. In the present study, oxytocin (OT) was used to increase the renal sodium loss and prolong the hydroelectrolyte abnormalities of ME-lesioned animals during the first few hours post-surgery. The objective was to determine whether OT-treated ME-lesioned animals increase their sodium appetite and water intake to restore the volume and composition of extracellular body fluid. Electrolytic lesion of the ME increased water intake, urinary volume and sodium excretion of food-deprived rats and also decreased urine osmolality and estimated plasma sodium concentration. OT administration at 8hours post-surgery reduced water intake, urine output and plasma sodium concentration and also increased urine osmolality and urine sodium excretion between 8 and 24hours post-lesion. From 24 to 30hours, more water and hypertonic NaCl was consumed by OT-treated ME-lesioned rats than by physiological saline-treated-ME-lesioned animals. Food availability from 30 to 48hours reduced the intake of hypertonic saline solution by ME/OT animals, which increased their water and food intake during this period. OT administration therefore appears to enhance the natriuretic effect of ME lesion, producing hydroelectrolyte changes that reduce the water intake of food-deprived animals. Conversely, the presence of hypertonic NaCl increases the fluid intake of these animals, possibly as a result of the plasma sodium depletion and hypovolaemic states previously generated. Finally, the subsequent increase in food intake by ME/OT animals reduces their need for hypertonic NaCl but not water, possibly in response to osmotic thirst. These results are discussed in relation to a possible transient activation of the ME with the consequent secretion of natriuretic peptides stored in terminal swellings, which would be augmented by OT administration. Electrolytic lesion of the ME may therefore represent a useful neurobiological model of CSW.

Effects of Oxytocin Administration on Oxidative Markers in the Temporal Lobe of Aged Rats

Considering the relevance of oxidative stress in aging and antioxidant properties of oxytocin, which we previously demonstrated, we studied the effects of intraperitoneal oxytocin administration (10 mg/kg body mass for 12 days) on enzymatic activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx), and also on malonic dialdehyde (MDA) level in the brain temporal lobe of aged (2-year-old) Wistar rats. In these rats, oxytocin treatment provided a significantly lower SOD enzymatic activity, somewhat greater GPx activity, and significantly lower MDA concentration, when compared to the respective indices in aged control rats. It is concluded that, due to its antioxidant effect, oxytocin can be considered a candidate for the development of a new therapeutic modality in aging and in related neuropsychiatric disorders.

The Effect of Intranasal Oxytocin on Measures of Social Cognition in Schizophrenia: A Negative Report.

Social cognition is impaired in patients with schizophrenia and is related to functional outcome. Neither current pharmacologic treatments for psychotic symptoms nor psychosocial interventions robustly improves measures of social cognition. Given this, the development of adjunctive treatments to improve functional outcome is a rational approach to treatment research in schizophrenia. The neuropeptide oxytocin is a candidate to treat deficits in social cognition due to its prosocial as well as anxiolytic effects. We report here results from a randomized, double-blind, parallel group 3 week clinical trial with daily administration of adjunctive intranasal oxytocin (20 IU twice daily) (n = 13) or placebo (n = 15). We examined the effect of oxytocin administration on measures of 4 domains of social cognition, as well as social functioning. After 3 weeks of oxytocin/placebo dosing, there was no significant difference favoring oxytocin between treatment groups in any outcome measure. These results add to the body of literature examining the effects of oxytocin on social cognition in schizophrenia. Further study is warranted.

Effects of oxytocin administration on receiving help.

Receiving help can be a "mixed blessing." Despite the many psychosocial benefits it can carry, it sometimes has negative psychological consequences, such as loss in self-esteem or enhanced guilt. It is, therefore, important to understand the factors that modify responses to receiving help from others. We explored the role of the hormone oxytocin (OT) on affective and social responses to receiving help, given the putative role of OT in social bonding and attunement. To this end, we manipulated whether help was received from a same-sex interaction partner (confederate) versus a control condition, crossed with a double-blind administration of intranasal OT (vs. placebo), and examined subjective and observer-rated participant responses to help. We observed significant interactions between OT and the help manipulation. In the placebo condition, receiving help from the interaction partner compared with the control condition had negative consequences, such that participants reported greater negative affect and came to view themselves and their interaction partners more negatively after interacting together on several tasks. What is important, however, is that OT administration buffered against these negative subjective responses to receiving help. Further, outside observers rated participants who received OT administration as expressing greater happiness and gratitude in response to help, relative to those who received placebo. In sum, in the context of receiving help from a stranger, oxytocin administration fostered more positive affective and social responses. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Oxytocin and Eating Disorders: A Narrative Review on Emerging Findings and Perspectives.

Background: The hypothalamic neuropeptide oxytocin regulates reproductive behavior and mother-infant interaction, and conclusive studies in humans indicate that oxytocin is also a potent modulator of psychosocial function. Pilot experiments have yielded first evidence that this neuropeptide moreover influences eating behavior.Methods: We briefly summarize currently available studies on the involvement of the oxytocin system in the pathophysiology of eating disorders, as well as on the effects of oxytocin administration in patients with these disorders.Results: Brain administration of oxytocin in animals with normal weight, but also with diet-induced or genetically induced obesity, attenuates food intake and reduces body weight. In normal-weight and obese individuals, acute intranasal oxytocin delivery curbs calorie intake from main dishes and snacks. Such effects might converge with the poignant social and cognitive impact of oxytocin to also improve dysfunctional eating behavior in the therapeutic context. This assumption has received support in first studies showing that oxytocin might play a role in the disease process of anorexia nervosa. In contrast, respective experiments in patients with bulimia nervosa and binge eating disorder are still scarce.Conclusions: We propose a framework of oxytocin’s role and its therapeutic potential in eating disorders that aims at integrating social and metabolic aspects of its pharmacological profile, and ponder perspectives and limitations of oxytocin use in the clinical setting.

149 Preliminary Results of the Oxytocin Treatment on the Collection of Cat Semen by Urethral Catheterization After Pharmacological Induction

Urethral catheterization after pharmacological induction (Ur.Ca.P.I.) has been developed as a method to collect semen from cats (Zambelli et al. 2008 Theriogenology 69, 485-490). This procedure is based on contraction of the vas deferens induced by the α-agonist medetomidine and the subsequent release of sperm into the urethra. To ensure adequate sedation, the medetomidine dosage is 130 µg kg−1. Usually, a single collection of semen is done by catheterization immediately after medetomidine takes effect. A 3.5 French (Fr) gauge urinary tom cat catheter with the tip cut is inserted 90 mm deep into the urethra. Even in the absence of clinical signs, the cut catheter tip may cause minor trauma to the urethral mucosa. Aims of this study were to test a new catheter and evaluate effects of oxytocin administration on quality and quantity of semen collected. The study was performed on 8 client-owned, pubertal domestic cats, 10 to 18 months old. These cats were randomly allocated into 2 groups: control and treatment, with 3 and 5 cats, respectively. In each group, 2 semen collections were performed. The catheter had a diameter of 4 Fr and a rounded tip without mandrel and it was inserted 90 mm deep. In both groups, the first collection was performed as effects of medetomidine were apparent. In the control group, the second collection was done 10 min later. However, in the treated group, 5 IU of oxytocin was injected intramuscularly immediately after semen collection, with the second collection performed 10 min later. Semen was evaluated for volume, concentration, rate of progressive motility, curvilinear speed (VCL), morphology, and vitality. Comparisons between collections and between groups were done with a Student’s t-test. Comparing the second versus first collection in the control group, there was only an increase in volume (9.33 v. 2.67 µL; P &lt; 0.05). In contrast, in the oxytocin group, all parameters evaluated were better (P &lt; 0.05) for the second collection. As expected, the first collection was not different between the 2 groups for any parameter. However, for the second collection, there were differences (P &lt; 0.05) between the oxytocin and the control group for volume (12.6 v. 3.7 µL), concentration (1252.6 v. 858 × 106 sperm mL−1), progressive motility (90.2 v. 77.8%), VCL (137.71 v. 117.94 µm s−1), morphologically normal sperm (87.0 v. 81.4%), and vitality (86.4 v. 82.8%). Oxytocin may be involved in mobilization of sperm from the epididymis. We concluded that oxytocin improved recovery of sperm from epididymal reserves, resulting in sperm with better morphology and function than those present in the vas deferens.