Oxytocin Concentrations Research Articles

Endocrine changes related to dog domestication: Comparing urinary cortisol and oxytocin in hand-raised, pack-living dogs and wolves

Dogs are exceptionally well adapted to life close to humans, and alterations in their endocrine system during the domestication process may be an underlying mechanism. In particular, it has been suggested that low circulating cortisol concentrations in conjunction with simultaneously high oxytocin concentrations may have resulted in dogs' increased docility (‘selection for tameness’ hypothesis) and heightened propensity to interact and form relationships with humans (‘hypersociability’ hypothesis) compared to wolves. To investigate this, we analyzed cortisol and oxytocin metabolite concentrations from urine samples of hand-raised, pack-living domestic dogs and their non-domestic relatives, grey wolves. Based on the hypotheses outlined above, we predicted lower cortisol but higher oxytocin concentrations in dogs than wolves. In contrast to our prediction, we found higher cortisol concentrations in dogs than wolves. However, oxytocin concentrations were higher in dogs compared to wolves although the effect was relatively small. Indeed, male dogs had the highest oxytocin concentrations while female dogs' oxytocin concentrations were comparable to wolves'. Feeding status, reproductive phase, and conspecific social interactions also significantly affected cortisol and oxytocin concentrations. Furthermore, we compared two methods of correcting for variable water content of urine samples. We discuss our results in light of physiological and behavioral changes during domestication and highlight the importance of accounting for confounding variables in future studies.

Intranasal (IN) Oxytocin Relieves Pain and Depressive Behavior in a Rodent Model of Mild Traumatic Brain Injury (TBI)

Evaluate the efficacy of intranasal oxytocin in relieving pain and associated depressive behavior in a rat model of mild TBI. Pain, anxiety, depression and cognitive impairment after TBI are sources of long-term disability for which there is no effective treatment. Decreases in endogenous oxytocin are associated with chronic pain and headache, and exogenous oxytocin reduces both pain and depressive behavior in animals and humans. This study examined the effects of intranasal oxytocin in pain and depressive behavior following TBI in rats. A standardized, reproducible, lateral fluid percussion rat model was employed using male Sprague-Dawley rats. Sham animals underwent the same procedure as the TBI animals except for the pressure pulse upon the dura. At 48-hour post procedure and establishment of hind paw and facial allodynia, 6 rats received IN oxytocin, 6 received IN vehicle. In 12 other rats, 16 ug oxytocin or vehicle was administered intravenously (IV). An additional 6 rats each received either IN oxytocin plus intraperitoneal (IP) oxytocin receptor antagonist atosiban or oxytocin plus vehicle. Rats were assessed on mechanical allodynia, conditioned place preference, and the forced swim test (FST). Oxytocin concentrations in trigeminal ganglia (TG), pons, spinal cord, and olfactory bulb were measured by ELISA immunoassay. IN oxytocin, but not IV or vehicle, attenuated both reactive and spontaneous pain following mild TBI as well as depressive behavior upon FST. This effect was blocked by atosiban, confirming an effect via oxytocin receptors. Immunoassay demonstrated concentrating of oxytocin primarily in TG. IN oxytocin was effective in relieving pain and associated depressive behavior of TBI in this model and has potential to be a safe and effective treatment for TBI headaches and post-concussion syndrome.

Key Roles of Cyclooxygenase 2-Protein Kinase A-Hyperpolarization-activated Cyclic Nucleotide-gated Channel 3 Pathway in the Regulation of Oxytocin Neuronal Activity in Lactating Rats with Intermittent Pup-Deprivation

Suckling-evoked pulsatile release of oxytocin (OT) from the posterior pituitary plays a key role in breastfeeding, which relies on burst-like discharges of OT neurons. To explore cellular mechanisms regulating OT neuronal activity, using lactating rats with pup-deprivation (PD) during postpartum day 1–5, we observed the involvement of prostaglandin, cyclic AMP/protein kinase A (PKA) and hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3) signaling pathway in OT neuronal activity. PD gradually reduced lactation efficiency. Intermittent PD (IPD) was largely reversed by intranasally-applied OT (IAO) but not by hypodermically-applied OT. IPD caused involution-like histological changes in the mammary glands, increased hypothalamic OT release but did not influence plasma OT concentrations. In the supraoptic nucleus, IPD increased OT receptor (OTR) expressions in OT neurons as well as Gαq subunit, Gβ subunit and cyclooxygenase 2 (Cox-2). These effects except that on Gβ subunit were reversed by IAO. Notably, IPD increased the expression of catalytic subunit of PKA in the SON, specifically in vasopressin neurons but not in OT neurons. In addition, IPD increased the expression of HCN3. IAO partially reversed these changes in the SON. Lastly, blocking HCN3 blocked excitation and burst firing in OT neurons-evoked by prostaglandin E2, a key mediator of OT-evoked burst firing; blocking Cox-2 or PKA reduced the molecular association between OTR and HCN3. Thus, there is a prostaglandin-cAMP/PKA–HCN3 pathway in the regulation of OT neuronal activity. PD disrupts lactation performance through uncoupling OTR and PKA-HCN3 signaling. The reversal effect of IAO highlights its therapeutic potential in PD-evoked hypogalactia.

Oxytocin and Three Kinds of Dangerous Behaviors in a Romantic Relationship: Playing, Suffering, and Stalking.

Romantic relationships are an essential element of healthy living. Although difficulties in love are encountered often, it seems that three kinds of behaviors in a romantic relationship are more susceptible to physical or psychiatric disorders: playing (sexually transmitted disease), suffering (major depressive disorder or suicide), and stalking (violence or homicide). Oxytocin plays an important role in pair-bonding. Elevated plasma oxytocin concentrations have been observed in new lovers when compared with singles. It is hypothesized that those who display these dangerous behaviors in a romantic relationship might possess specific oxytocin receptor gene aberrancy and the resultant deviant pair-bonding pattern is likely to recur in successive relationships. It is postulated that a blunted oxytocin surge might be observed in playing, whereas exaggerated oxytocin surge might be observed in suffering and stalking. The distinction between suffering and stalking might stem from the difference in their aggression tendencies. Those who suffer displays aggression toward self, while those who stalk displays aggression toward others. The exaggerated oxytocin concentrations in people who suffer and people who stalk might not be suppressed by the discouraging attitudes of their partners and might be maintained by rumination. Considering the whole-body influence of oxytocin, intranasal oxytocin application or gene therapy should be used exclusively for those who display these dangerous behaviors and not for the general population. Future research is warranted to confirm this hypothesis with analysis of modifiers such as gender.

The Effect of Slow Stroke Back Massage on Primary Dysmenorrhea: Levels of Beta-Endorphin, Interleukin-6, Tumor Necrosis Factor-α, and Pain Intensity

Objectives: Dysmenorrhea is one of several gynecological issues that occur among women of reproductive age. In addition, it appears as pain that forms in the pelvis or lower abdomen and spreads to the back and thighs. The peripheral blood among women with dysmenorrhea increases the synthesis and the concentration of oxytocin, F2α prostaglandin hormone, vasopressin, interleukin-6 (IL-6), and tumor necrosis factor-α (TNFα). In this regard, this study aimed to determine the effect of slow-stroke back massage (SSBM) on the levels of β-endorphins, IL-6, TNF-α, and menstrual pain intensity (MPI). Materials and Methods: Based on the aim of the study, the posttest only quasi-experimental method with the control group design approach, pretest-posttest control group approach, and purposive sampling techniques were applied for sample selection. The samples were divided into SSBM and control groups each containing 20 subjects. The numeric rating scale (NRS), β-endorphin, IL-6, and TNFα levels were measured using the indirect enzyme-linked immunosorbent assay. Then, data were analyzed by paired sample t test and independent-samples t test with α ≤ 0.05. Results: The results revealed that SSBM had an effect on the intensity of menstrual pain (P<0.05), and differences were found between β-endorphin levels, IL-6, TNFα, and MPI among SSBM and control (P<0.05) groups. Accordingly, SSBM can stimulate releasing β-endorphin levels and reducing pro-inflammatory cytokines (IL-6 and TNFα). Conclusions: In general, SSBM is a nonpharmacological action that is effective in primary dysmenorrhea.

Effects of DDT, DDE, aldrin and dieldrin on prostaglandin, oxytocin and steroid hormone release from smooth chorion explants of cattle

Chlorooganic xenobiotics (XBs) such as DDT, DDE, aldrin and dieldrin interfere with release of hormones from chorionic villi that are necessary for sustaining the normal course pregnancy: prostaglandins (PGs), oxytocin (OT), progesterone (P4) and estradiol (E2). Approximately 20 %–40 % of these hormones originate from the smooth chorion. The aim of current studies was to investigate effects of these XBs on synthesis and release of PGE2, PGF2α, OT, P4 and E2 from explants of smooth chorion of cattle, obtained during the120–150 and 151–180 day gestational period. Explants were incubated with DDT, DDE, aldrin or dieldrin at concentrations of 1 and 10 ng/mL for 24 h, and concentrations of PGE2, PGF2α, OT, P4 and E2 in post incubation medium and the relative abundances of COX-2, PTGES, AKR1B1, NP-I/OT, PAM, HSD3B, and CYP19A1 mRNA transcripts in tissue explants were determined. The XBs did not have effects on cell viability in explants (P > 0.05), however, there were effects on prostaglandins, OT and P4 secretion and relative abundance of mRNA transcript for genes encoding the main enzymes involved in synthesis of these hormones (P < 0.05). The XBs that were evaluated did not have effects on E2 synthesis and secretion (P > 0.05). In summary, XBs evaluated in the present study had effects on the pattern of prostaglandin secretion, and can increase OT and P4 release from smooth chorion explants. Because XBs inhibit hormonal action throughout the chorion, there is an increase in risk of abortions or premature births in animals.

Methylation of OXT and OXTR genes, central oxytocin, and social behavior in female macaques

Oxytocin (OXT) and its receptor (OXTR) are encoded by OXT and OXTR, respectively. Variable methylation of these genes has been linked to variability in sociability and neuroendophenotypes. Here we examine whether OXTR or OXT methylation in blood predicts concentrations of OXT in cerebrospinal fluid (CSF) (n = 166) and social behavior (n = 207) in socially-housed female rhesus macaques. We report a similarity between human and rhesus CpG sites for OXT and OXTR and a putative negative association between methylation of two OXTR CpG units with aggressive behavior (both P = 0.003), though this finding does not survive the most stringent correction for multiple comparison testing. We did not detect a statistically significant association between methylation of any CpG sites and CSF OXT concentrations, either. Because none of the tested associations survived statistical corrections, if there is any relationship between blood-derived methylation of these genes and the behavioral and physiological outcomes measured here, the effect size is too small to be detected reliably with this sample size. These results do not support the hypothesis that blood methylation of OXT or OXTR is robustly associated with CSF OXT concentration or social behavior in rhesus. It is possible, though, that methylation of these loci in the brain or in cheek epithelia may be associated with central OXT release and behavior. Finally, we consider the limitations of this exploratory study in the context of statistical power.

Oxytocin Promotes C6 Glial Cell Death and Aggravates Hydrogen Peroxide-induced Oxidative Stress

Background. Recent studies have shown that oxytocin plays a vital role in neurons and glial cells. However, its effect on hydrogen peroxide (H2O2)-induced oxidative stress as well as cyclooxygenase-1 (COX-1) and COX-2 in glial cells are still unclear. Objective. This study aims to examine the effect of oxytocin on glial cell viability, oxidative stress, COX-1, and COX-2 in C6 glial cells after exposure to H2O2. Methods. In this study, C6 glioma cell line was used to study the effect of oxytocin on the glial cell in four cell groups. The control group was untreated. Cells in the H2O2 group were treated with 0.5 mM H2O2 for 24 h. Cells in the oxytocin group were treated with various concentrations (0.25, 0.5, 1, and 2 μg/mL) of oxytocin for 24 h. Cells in the oxytocin+H2O2 group were pre-treated with various concentrations (0.25, 0.5, 1, and 2 μg/mL) of oxytocin for 1 h before 24-h exposure to 0.5 mM H2O2. Cell viability was evaluated using XTT assay. Total antioxidant status and total oxidant status (TOS), COX-1, and COX-2 levels in the cells were measured by commercial kits. Results. Oxytocin with various concentrations significantly decreased the viability of C6 cells after H2O2-induced oxidative stress (P &lt; 0.01). It also significantly increased the levels of TOS, COX-1, and COX-2 in C6 cells after H2O2-induced oxidative stress (P &lt; 0.001). Conclusion. Oxytocin increases glial cell death after H2O2-induced oxidative damage in C6 cells, along with upregulation of COX-1 and COX-2 levels.

Changes in oxytocin concentrations in saliva of pigs after a transport and during lairage at slaughterhouse

Oxytocin is associated with reproductive physiology but also with welfare and positive emotions. In this study, oxytocin was measured in saliva samples of 45 pigs that were collected before being transported to the slaughterhouse, at the time of arrival and 4 h after arrival to the slaughterhouse. Two previously validated assays, one that measures free oxytocin and other that measures oxytocin linked to proteins, were used. In addition, cortisol, salivary alpha-amylase (sAA), total esterase activity (TEA), butyrylcholinesterase (BChE) and lactate dehydrogenase (LDH), which are biomarkers associated with stress and pain in pigs, were measured. The results showed a decrease in free and protein-linked oxytocin concentrations at 4 h after transport compared with the time before transport, while cortisol, sAA, TEA, BChE and LDH showed an increase at 4 h after transport compared with the time before transport. Based on these results it can be concluded that the transport and lairage at slaughterhouse in the conditions of this study produce a decrease in oxytocin in the saliva of pigs that could indicate a reduced emotional well-being.

Oxytocin increases the pleasantness of affective touch and orbitofrontal cortex activity independent of valence

Touch plays a crucial role in affiliative behavior and social communication. The neuropeptide oxytocin is released in response to touch and may act to facilitate the rewarding effects of social touch. However, no studies to date have determined whether oxytocin facilitates behavioral or neural responses to non-socially administered affective touch and possible differential effects of touch valence. In a functional MRI experiment using a randomized placebo-controlled, within-subject design in 40 male subjects we investigated the effects of intranasal oxytocin (24IU) on behavioral and neural responses to positive, neutral and negative valence touch administered to the arm via different types of materials at a frequency aimed to optimally stimulate C-fibers. Results showed that oxytocin significantly increased both the perceived pleasantness of touch and activation of the orbitofrontal cortex independent of touch valence. The effects of OT on touch-evoked orbitofrontal activation were also positively associated with basal oxytocin concentrations in blood. Additionally, anterior insula activity and the functional connectivity between the amygdala and right anterior insula were enhanced only in response to negative valence touch. Overall, the present study provides the first evidence that oxytocin may facilitate the rewarding effects of all types of touch, irrespective of valence.

The Impact of a 20-Minute Animal-Assisted Activity Session on the Physiological and Emotional States in Patients With Fibromyalgia

ObjectiveTo study the direct physiological and emotional impact of an animal-assisted activity (AAA) session (a form of complementary and integrative medicine) in patients with fibromyalgia (FM). Patients and MethodsThe study population consisted of 221 participants with FM who were attending Mayo Clinic’s Fibromyalgia Treatment Program between August 5, 2017, and September 1, 2018. This was a randomized controlled trial. Participants were randomly assigned to either the treatment group (a 20-minute session with a certified therapy dog and handler) or the control group (a 20-minute session with a handler only). To gain a better understanding of the direct physiological and emotional effects of AAA in patients with FM, we used multiple noninvasive physiologic-emotional biomarkers, including salivary cortisol and oxytocin concentrations, tympanic membrane temperatures, and various cardiac parameters, in addition to standardized pain and mood-based questionnaires. ResultsResults show a decrease in heart rate, an increase in heart rate variability, an increase in well-being survey scores, an increase in salivary oxytocin, and subsequent tympanic membrane temperature changes, suggesting that participants in the treatment group were in a more positive emotional-physiologic state as a result of the AAA session compared with the control group. ConclusionOur results suggest that a 20-minute therapy dog visit in an outpatient setting can significantly and positively impact the physical and mental health of patients with FM.

Stability of Oxytocin Preparations in Malawi and Rwanda: Stabilizing Effect of Chlorobutanol.

.Oxytocin is used for the prevention and treatment of postpartum hemorrhage, the leading cause of maternal mortality in low- and middle-income countries. Because of the high instability of oxytocin, most products are labeled for storage at 2–8°C. Some other products are on the market which are labeled for non-refrigerated storage, but independent evaluations of their stability hardly exist. In the present study, seven brands (nine batches) of oxytocin were purchased from wholesalers and medical stores in Malawi and Rwanda and investigated by accelerated stability testing according to the ICH/WHO guidelines. Two oxytocin brands approved by a stringent regulatory authority (SRA) or by the WHO Prequalification of Medicines program and purchased in Europe were used as comparison. All investigated brands which were either produced in countries with SRAs, or were WHO-prequalified products, were labeled for storage at 2–8°C, and all of them passed stability testing with very good results. Even exposure to 25°C or 30°C for several months hardly affected their oxytocin content. However, two other investigated brands were labeled for non-refrigerated storage, and both of them had been produced in countries without SRAs. These two preparations showed not higher but lower stability than the brands labeled for storage at 2–8°C, and, for both of them, noncompliance with pharmacopoeial specifications was found after accelerated stability testing. At 40°C, and in forced degradation studies at 80°C, chlorobutanol showed a remarkable stabilizing effect on oxytocin, which may deserve further investigation. The results of the present study support the policy “Buy Quality Oxytocin, Keep It Cool.”

Maternal perinatal depression, circulating oxytocin levels and childhood emotional disorders at 4 years of age: The importance of psychosocial context

Oxytocin has been a hormone of interest in understanding both depression and parenting. Here, the role of oxytocin has been explored in understanding the interaction between perinatal depression, history of trauma and subsequent longer-term child socio-emotional outcomes. Data were obtained from 203 pregnant women from the Mercy Pregnancy and Emotional Wellbeing Study (MPEWS), a pregnancy cohort study with data collected across pregnancy, postpartum and until 4 years for mother and child. Maternal antenatal depression was measured using the Structured Clinical Interview for DSM-IV (SCID-IV) together with the Childhood Trauma Questionnaire to measure maternal trauma history. Maternal oxytocin levels were measured by enzyme immunoassay following extraction at four time points across pregnancy and the postpartum. The offspring consisted of 203 children followed up from birth until 4 years of age when they were assessed for DSM 5 depression and anxiety disorders (emotional disorders) using the Preschool Age Psychiatric Assessment. Maternal oxytocin levels increased over pregnancy and the postpartum in both control and depressed women with no difference between groups. Maternal childhood trauma and antenatal antidepressant use was also not associated with maternal oxytocin levels. Lower gestational age, maternal depression and early childhood trauma, and late pregnancy oxytocin concentrations were associated with later childhood emotional disorders; together they predicted 10% of variance for emotional disorders. Oxytocin is a hormone whose role in understanding intergenerational risk from pregnancy to child emotional disorders is dependent on relational context. Future research can expand on understanding these important early predictors of childhood mental health.

Perceived pleasantness of gentle touch in healthy individuals is related to salivary oxytocin response and EEG markers of arousal.

Affective touch plays an important role in human social bonding, affiliative behavior, and in general emotional well-being. A system of unmyelinated low-threshold mechanosensitive C-type afferents innervating hairy skin (C-tactile or CT system) is postulated to provide the neurophysiological background of affective touch perception. C-tactile afferents respond optimally to soft and slow strokes, and this response correlates positively with pleasure ratings of tactile stimuli. As gentle touch is consistently associated with oxytocin release further promoting prosocial behavior, it has been suggested that this effect is mediated by the response of C-tactile afferents. This study assesses a possible link between CT-optimal touch, its subjective pleasantness, EEG indices of cortical arousal, and peripheral oxytocin response. EEG was recorded in 28 healthy volunteers during resting state and tactile stimulation[gentle slow brush strokes on forearm (CT-targeted touch) and palm (non-CT-targeted touch)]. Saliva samples were collected before and after the touch stimulation. Oxytocin concentration increase was significantly associated with greater subjective ratings of CT-targeted touch but not of non-CT-targeted touch, and with lower peak alpha frequency values indicating decreased cortical arousal. The findings suggest that CT-targeted stimulation triggers oxytocin release but only when the touch is perceived at an individual level as having clearly positive affective salience. This corresponds to previous studies reporting that oxytocin response to touch can be related to different personality factors, and bears important implications for planning touch-based interventions in social and medical care.

Ejaculate Collection Influences the Salivary Oxytocin Concentrations in Breeding Male Pigs.

Simple SummaryThis study aimed to evaluate how the process of ejaculate collection affects oxytocin concentrations in saliva of boars used in artificial insemination. Saliva samples of 33 boars were collected the day before ejaculate collection, during the ejaculation time, and two hours after ejaculate collection. Free oxytocin and oxytocin linked to proteins were quantified in these saliva samples. Oxytocin concentrations during the ejaculation time were higher than the day before with oxytocin linked to proteins showing higher differences. In addition, younger boars, boars with higher libido intensity and boars of the Pietrain breed showed higher values of oxytocin in saliva during ejaculation than the day before. This study demonstrated that ejaculation influences the salivary oxytocin concentrations boars.The objective of the present study was to evaluate the possible changes of oxytocin concentrations in saliva during and after ejaculate collection in breeding boars usually used in artificial insemination programs. Saliva samples of 33 boars were collected the day before ejaculate collection (DB), during the ejaculation time (T0) and two hours after ejaculate collection (T2). Free oxytocin and oxytocin linked to proteins concentrations were measured by two methods previously developed and validated for saliva of pigs. Younger boars, boars with higher libido intensity and boars of the Pietrain breed showed higher values of oxytocin in saliva during ejaculation than the day before. In addition, boars with higher libido showed higher concentrations two hours after ejaculate collection than during the day before. These changes were of higher magnitude and significance when oxytocin linked to proteins was measured. In conclusion, this study demonstrated for the first time that ejaculation influences the salivary oxytocin concentrations in breeding boars, although this influence varies according to age, libido and breed.

Burnout in university faculty: An interaction between subjective sleep quality and the OXTR rs2268498 polymorphism

BackgroundJob burnout is a stress-related syndrome influenced by both genetic and environmental factors. Poor sleep quality acting as a stressor may lead to job burnout. The oxytocin receptor gene (OXTR) related to stress reactivity may also exert an effect on job burnout. We aimed to explore the effect of sleep quality, a functional OXTR rs2268498 polymorphism, and their interaction on job burnout in the Chinese population, which has not been explored yet. MethodsA preliminary study was performed using a cross-sectional design. The Pittsburgh Sleep Quality Index (PSQI) and the Malash Burnout Inventory (MBI) were measured from 575 healthy subjects. The OXTR rs2468498 polymorphism was genotyped in 376 subjects. ResultsThere were significant main effects of sleep quality (p<0.05), but not of the OXTR rs2468498 genotype on burnout. Interestingly, the interaction between sleep quality and the rs2468498 genotype was significant (p<0.05). In the poor sleep group, the C allele (C/C and T/C) carriers showed higher Emotional Exhaustion level than T homozygotes, while in the good sleep group, the C allele carrier showed a lower Emotional Exhaustion level. LimitationsThis study covered subjects from only one university and the sample size for genotyping was relatively small. As we analyzed only the OXTR rs2268498 polymorphism, this study could not reveal the effects of the cerebrospinal oxytocin concentration and the haplotypes. ConclusionsOur findings suggest that the OXTR polymorphism modulates the influence of subjective sleep quality on burnout. We conclude that the C allele of the OXTR rs2468498 polymorphism plays a susceptible role in job burnout.

Labeled oxytocin administered via the intranasal route reaches the brain in rhesus macaques

Oxytocin may have promise as a treatment for neuropsychiatric disorders. Its therapeutic effect may depend on its ability to enter the brain and bind to the oxytocin receptor. To date, the brain tissue penetrance of intranasal oxytocin has not been demonstrated. In this nonhuman primate study, we administer deuterated oxytocin intranasally and intravenously to rhesus macaques and measure, with mass spectrometry, concentrations of labeled (exogenously administered) and endogenous oxytocin in 12 brain regions two hours after oxytocin administration. Labeled oxytocin is quantified after intranasal (not intravenous) administration in brain regions (orbitofrontal cortex, striatum, brainstem, and thalamus) that lie in the trajectories of the olfactory and trigeminal nerves. These results suggest that intranasal administration bypasses the blood–brain barrier, delivering oxytocin to specific brain regions, such as the striatum, where oxytocin acts to impact motivated behaviors. Further, high concentrations of endogenous oxytocin are in regions that overlap with projection fields of oxytocinergic neurons.

Brief Report: Relationship Between Cotinine Levels and Peripheral Endogenous Concentrations of Oxytocin, β-Endorphin, and Orexin in Individuals With Both Alcohol and Nicotine Use Disorders.

In this secondary analysis of a pilot clinical trial with individuals with alcohol and nicotine use disorders, we investigate the relationship between serum concentrations of oxytocin, β-endorphin, melatonin, α-melanocyte-stimulating hormone, substance P, and orexin, with objective biomarkers (salivary cotinine and serum γ-glutamyl transferase [GGT]) as well as with self-reported smoking and alcohol drinking. Biomarkers for a total of N = 19 participants were analyzed using multiplexed, competitive format immune-assay (peptides) and enzyme competitive immunoassay (saliva). A regression analysis using Pearson's correlation coefficient was utilized to determine correlations. We controlled for multiple comparisons, checked for collinearities, and ran two-sided statistical tests. We found significant positive correlations for cotinine and oxytocin (P = .002), β-endorphin (P = .008), and orexin (P < .001), but not for either GGT or self-reported smoking or alcohol drinking. These preliminary results suggest a relationship between cotinine and oxytocin, β-endorphin, and orexin, which opens up new potential hypotheses on the potential role of these endocrine pathways in tobacco smokers. (Am J Addict 2021;30:88-91).

Serum oxytocin concentrations in current and recent suicide survivors are lower than in healthy controls

BackgroundSuicide and suicide attempts are dramatic events both for the individuals concerned and for their social circles. From a psychopathological perspective, suicidal behavior could be understood as a severe breakdown in relations with their social worlds. Oxytocin is a neuropeptide highly involved in the perception of facets of social relationship such as their quality feelings of belongingness, and mutual trust. Given this, we expected that serum oxytocin concentrations would be lower in current and recent suicide survivors than in healthy controls. MethodsA total of 48 participants (mean age: 27 years; 62.5% females) took part in the study. Of these, 16 (62.5% females) survived a suicide attempt 12–24 h ago; 16 (62.5% females) had made a suicide attempt about 12 weeks ago, and 16 (62.5% females) were healthy age- and gender-matched controls. Blood samples were taken in the morning to assess serum oxytocin concentrations. Participants also completed questionnaires covering sociodemographic information and a scale assessing suicidal ideation. ResultsCompared to healthy controls, suicide survivors had significantly lower serum oxytocin concentrations, but these levels did not differ between current and recent suicide survivors. Compared to healthy controls and recent suicide attempters, current suicide attempters recorded significantly higher scores on the Beck scale for suicidal ideation. Across the sample as a whole, higher scores for suicidal ideation were associated with lower serum oxytocin concentrations. Serum oxytocin concentrations and scores on the Beck scale for suicidal ideation did not differ between females and males. ConclusionsGiven that oxytocin is a neurobiological correlate of subjectively perceived quality of social interaction and social relationships, the results support the notion that suicide attempts are closely linked to suicide survivors' perceptions of the quality of their social lives. Speculatively, and based on the serum oxytocin concentrations, it also appears that 12 weeks after a suicide attempt, the survivor's perceived quality of social life has not significantly improved.

Salivary oxytocin after oxytocin administration: Examining the moderating role of childhood trauma

Although oxytocin administration influences behavior, its effects on peripheral oxytocin concentrations are mixed and derived from studies on healthy subjects. Additionally, trauma attenuates the behavioral effects of oxytocin, but it is unknown whether it also influences its effect on peripheral circulation. This study examined whether salivary oxytocin increased after oxytocin administration and whether trauma attenuated this effect. We conducted a randomized, double-blind, placebo-controlled, within-subjects study in 100 male adolescents living in residential youth care facilities. Participants self-administered intranasally 24 IU of oxytocin and placebo (one week later) and provided a saliva sample before and 15 min after administration. Salivary oxytocin increased significantly after oxytocin administration, but this effect might be inflated by exogenous oxytocin reaching the throat. Trauma did not moderate this effect. Our findings suggest that trauma did not attenuate the effect of oxytocin administration on salivary oxytocin, but more robust methodologies are recommended to draw more solid conclusions.