Menstrual cycle-related changes in plasma oxytocin are relevant to normal sexual function in healthy women

Diminished plasma oxytocin in schizophrenic patients with neuroendocrine dysfunction and emotional deficits

Polydipsic hyponatremic schizophrenic patients (PHS) exhibit enhanced plasma arginine vasopressin (pAVP) and hypothalamic pituitary adrenal (HPA) axis responses to stress that appear attributable to anterior hippocampal dysfunction. Neuroanatomic and electrophysiologic studies indicate oxytocin activity in PHS patients should also be affected. Furthermore, oxytocin normally diminishes HPA responses to stress and facilitates cognitive and behavioral functions impaired in schizophrenia, suggesting that diminished oxytocin activity could contribute to this subsets' neuropsychiatric disorder. In the present study, we measured plasma oxytocin levels at intervals before and after stress induction in six polydipsic hyponatremic (PHS), four polydipsic normonatremic (PNS), five nonpolydipsic normonatremic schizophrenic (NNS) patients and seven healthy controls. Most of these subjects also completed studies measuring their medial temporal lobe volumes, their hippocampal-mediated HPA feedback and their ability to discriminate different facial emotions (an oxytocin-sensitive measure which is markedly impaired in schizophrenia). Results demonstrated that 1) plasma oxytocin levels were lower (p=.006) in hyponatremic patients relative to the other three groups, whose levels were similar and did not change. Oxytocin levels across all subjects were 2) inversely correlated with anterior hippocampal (p=.004) (but not posterior hippocampal or amygdala volumes), and 3) directly correlated with the integrity of hippocampal-mediated HPA feedback (p=.039). Finally, 4) oxytocin levels predicted schizophrenic patients' ability to correctly identify facial emotions (p=.004). These preliminary data provide further evidence that neuroendocrine dysfunction in PHS reflects anterior hippocampal pathology and contributes to a characteristic neuropsychiatric syndrome.

Individual differences in emotional expressivity predict oxytocin responses to cortisol administration: Relevance to breast cancer?

Reduced emotional expression has been consistently related to susceptibility or fast progression of breast cancer. Breast cancer development and reduced emotional expression have both been related to rejection- and separation-related conditions. The neuropeptide oxytocin is low in response to rejection or separation. Recent results suggest that oxytocin may protect against the development of breast cancer and slow its progression. In the present study, we investigated if individual differences in emotional expressivity relate to basal or cortisol-stimulated plasma oxytocin. Healthy female subjects were treated with placebo or 35mg of cortisol orally in a double-blind within-subject study. Seventy minutes later, blood was sampled for determination of oxytocin and cortisol levels. We found an interaction between treatment condition and Emotional Expression-out scores: after cortisol treatment, oxytocin levels increased proportional to Emotion Expression-out score. These preliminary findings provide a potential mechanism for associations in the literature between emotional expressive behavior and breast cancer.

Anxiety, cortisol, and attachment predict plasma oxytocin

Oxytocin and attachment seem to interact in suppressing subjective anxiety and physiological stress responses. In this study we investigated the relationships between individual differences in trait attachment scores, state and trait anxiety, plasma cortisol, and plasma oxytocin levels in healthy premenopausal women. Attachment proved to be a strong positive predictor of oxytocin levels, which were also positively predicted by cortisol levels and state and trait anxiety. The relationship between oxytocin and state anxiety was modulated by attachment scores. The present results may help interpreting seeming contradictions in the recent literature on oxytocin, attachment, and stress in humans, by suggesting that context effects determine which relationships are found in different studies: anxiolytic effects of oxytocin in a context of partner support versus stress- or cortisol-induced oxytocin responses in a context of distress or increased cortisol.

Sexual function in men and women with neurological disorders

The advent of non-invasive functional brain imaging has clarified which regions of the brain are recruited during sexual arousal. Injuries to those regions, and to the spinal cord and peripheral nerves that link genitalia to limbic and cognitive centres, can profoundly influence sexual wellbeing. In epilepsy, expressions of hypersexuality and hyposexuality interact with the location of epileptogenic foci in the temporolimbic circuitry, and are tempered by the sexual effects of drug treatments. We outline the sexual consequences of epilepsy, stroke, multiple sclerosis, Parkinson's disease, and other common neurological disorders. Management of sexual dysfunction from both disease and treatment is discussed. Nerve-sparing techniques could mitigate the substantial sexual dysfunction in both men and women through surgical disruption of the autonomic nerves during radical pelvic surgery.

Uterine contractility in response to different prostaglandins: results from extracorporeally perfused non-pregnant swine uteri

BACKGROUND

Prostaglandins (PGs) are important stimulators of uterine contractility. Limited data are available at present on the effects of different PGs on uterine contractility, measured using intraluminal pressure changes in the complete uterus. The goal of this study was to assess dynamic changes in uterine contractility and peristalsis in response to PGs in comparison with the effects of oxytocin administration.

METHODS

An extracorporeal perfusion model of swine uteri was used, which keeps the uterus in a functional condition, and is appropriate for the study of physiological questions. Oxytocin- and PG-induced uterine contractility and peristalsis were assessed using an intrauterine double-chip microcatheter.

RESULTS

A dose-dependent increase in intrauterine pressure (IUP) in the isthmus uteri (P < 0.001) and the corpus uteri (P < 0.001) was observed after the administration of PGF(2alpha) and oxytocin, which reached a plateau after further stimulation. A dose-dependent increase in IUP in the isthmus uteri (P < 0.001) and the corpus uteri (P < 0.001) was also observed after the administration of PGE(1) and PGE(2), with a plateau in IUP in the middle-concentration range and a decrease in the course of further stimulation. PGE(2) caused significantly more contractions starting in the corpus uteri and moving to the isthmus uteri (P = 0.008). The direction of most contractions caused by PGE(1), PGE(2) and oxytocin differed from that of PGF(2alpha).

CONCLUSIONS

This study demonstrates that the PGs tested modulate contractility in non-pregnant swine uteri in a characteristic way, resulting in different contractility patterns.

Women's sexual function improves when partners are administered vardenafil for erectile dysfunction: a prospective, randomized, double-blind, placebo-controlled trial

INTRODUCTION

There are limited data concerning the sexual function of women whose male partners receive pharmacological treatment for erectile dysfunction (ED).

AIM

One objective of this research was to prospectively compare the efficacy of vardenafil vs. placebo administered to men with ED in improving men's and women partners' sexual function and satisfaction. Another goal was to assess the relationship of erectile function changes in men with ED receiving treatment with sexual function changes in women partners not directly receiving treatment.

METHODS

A randomized, double-blind, placebo-controlled, multi-institutional comparison of vardenafil vs. placebo was performed in 229 couples (treated man with ED>6 months and untreated woman partner). Co-primary outcomes for which this research was statistically powered were Sexual Encounter Profile (SEP3) (treated man with ED) and Sexual Life Quality Questionnaire (mSLQQ-QOL) (untreated woman partner).

MAIN OUTCOME MEASURES

Erectile function changes in men with ED receiving vardenafil vs. placebo were compared at last observation carried forward (LOCF) in SEP3, International Index of Erectile Function (IIEF-EF) and Erection Quality Scale (EQS). Sexual function at LOCF in women partners was determined by mSLQQ-QOL and Female Sexual Function Index (FSFI).

RESULTS

Compared with placebo at LOCF, vardenafil significantly increased least square (LS) mean scores in: (i) overall per-treated male SEP3 success rate, IIEF-EF, and EQS; and (ii) mSLQQ-QOL, total FSFI and sexual desire, subjective arousal, lubrication, orgasm and satisfaction FSFI domains in untreated women partners. Treatment-related improvement in erectile function as assessed by IIEF-EF and EQS was correlated reliably with improvement in women partners' FSFI total and individual domain scores.

CONCLUSIONS

Vardenafil is an effective ED treatment in men that also significantly improves sexual function/satisfaction in untreated women partners. Women partners' sexual function improvements relate significantly and consistently to treatment-related improvements in men's erectile function. ED management should emphasize both members of the couple.

Role of estrogen and progesterone in the regulation of uterine peristalsis: results from perfused non-pregnant swine uteri

BACKGROUND

Adequate uterine contractility and peristalsis are involved in the transport of semen and gametes and in successful embryo implantation. Estrogen and progesterone fluctuate characteristically during the menstrual cycle. It has been suggested that both hormones influence uterine peristalsis in characteristic ways.

METHODS

An extracorporeal perfusion model of the swine uterus was used that keeps the uterus in a functional condition and is suitable for the study of physiological questions. The effects of estrogen and progesterone on oxytocin-induced uterine peristalsis were assessed using an intrauterine double-chip microcatheter.

RESULTS

Estrogen perfusion was associated with an increase in intrauterine pressure (IUP) in a dose-dependent manner. There was a significant difference between the IUP increase measured in the isthmus uteri and that in the corpus uteri, resulting in a cervico-fundal pressure gradient. Estrogen perfusion resulted in a significantly higher rate of peristaltic waves starting in the isthmus uteri and directed towards the corpus uteri. Progesterone was able to antagonize the estrogen effect in general.

CONCLUSIONS

This study demonstrates that estrogen and progesterone have differential effects in the regulation of uterine peristalsis. The present observation shows that estrogen stimulates uterine peristalsis and is able to generate a cervico-fundal direction of peristalsis, whereas progesterone inhibits directed uterine peristalsis.

Perfused Non-Pregnant Swine Uteri: A Model for Evaluating Transport Mechanisms to the Side Bearing the Dominant Follicle in Humans

Adequate uterine contractility and periovulatory peristalsis, interpreted as "rapid sperm transport" to the side bearing the dominant follicle, may be a precondition for successful reproduction in humans. Estrogen and progesterone fluctuate characteristically during the menstrual cycle, and their source is the dominant follicle and corpus luteum. The question is, how is the direction to the left or right side of transport mechanisms influenced? An extracorporeal perfusion model of the swine uterus was used that maintained the uterus in a functional condition and that was suitable for the study of physiological questions. The effects of side-dependent estrogen, progesterone, and estrogen plus progesterone perfusion on oxytocin-induced uterine peristalsis were assessed using two intrauterine microcatheters placed in each horn of the swine uterus. Estrogen perfusion was associated with an increase in intrauterine pressure (IUP) in a dose-dependent manner only in the estrogen-perfused horn of the swine uterus. There was a significant difference between the IUP increase measured in the estrogen-perfused horn and that in the non estrogen-perfused horn of the swine uterus. Progesterone perfusion showed no effect in general. Furthermore, progesterone antagonized the estrogen effects. This study demonstrates that side-dependent estrogen perfusion resulted in side-dependent contractility in the swine uterus perfusion system used. These observations show that estrogen stimulates uterine contractility in the estrogen-perfused uterine horn and that estrogens may be the "trigger" for the transport mechanisms to the side bearing the dominant follicle during the periovulatory phase through their locally increased concentration and distribution via the utero-ovarian counter-current system in humans.

Short-term effects of alcohol consumption on the hormonal milieu and mood states in nulliparous women

The present study was designed to determine the short-term effects of alcohol consumption on hormonal responses and mood states in nulliparous women who have regular menstrual cycles. To this aim, we conducted a within-subjects design study in which eight women consumed a 0.4-g/kg dose of alcohol in orange juice during one test session (alcohol condition) and an equal volume of orange juice (control condition) during the other. Changes in plasma prolactin, oxytocin and cortisol levels, blood alcohol concentrations (BACs), and mood states were compared. BAC peaked at approximately 36.7+5.4 min after the consumption of the alcoholic beverage and decreased thereafter. Alcohol consumption significantly increased the area under the concentration-time curve (AUC) of prolactin (P<.01) and decreased the oxytocin AUC (P=.04) when compared to the control condition. Cortisol AUCs were not different across the two experimental conditions. Similar to that previously observed in lactating women, changes in prolactin and oxytocin paralleled changes in feelings of drunkenness. The magnitude and persistence of the alcohol-induced hormonal changes in nulliparous women were significantly less pronounced than those observed in lactating women, further highlighting the dynamics of the system under study during lactation.