Manuela Martinez

Effects of competition and its outcome on serum testosterone, cortisol and prolactin

In various species, competitive encounters influence hormonal responses in a different way depending on their outcome, victory or defeat. This study aimed to investigate the effects of sports competition and its outcome on hormonal response, comparing it with those displayed in situations involving non-effort and non-competitive effort. To this end, serum testosterone (T), cortisol (C) and prolactin (PRL) were measured in 26 judoists who participated in three sessions (control, judo fight and ergometry). The relationship between hormonal changes and psychological variables before and after the fight were also analysed. Our results showed a hormonal response to competition, which was especially characterized by an anticipatory rise of T and C. Depending on outcome, significant higher C levels were found in winners in comparison to losers through all the competition but not in T or PRL, both groups expending a similar physical effort. Furthermore, similar hormonal responses to the fight and to a non-competitive effort with the same caloric cost were found, other than with PRL. Winners showed a higher appraisal of their performance and satisfaction with the outcome, and perceived themselves as having more ability to win than losers, although there were no significant differences in motivation to win. Finally, the relationships found between T changes in competition and motivation to win, as well as between C response and self-efficacy suggest that in humans hormonal response to competition is not a direct consequence of winning and losing but rather is mediated by complex psychological processes.

Social defeat and subordination as models of social stress in laboratory rodents: A review

This paper is a review of the main research topics currently investigated in laboratory rodents using the stress of defeat or subordination as ethologically relevant models of social stress. First, the main characteristics of the resident/intruder paradigm and the colony models are given. Second, a general description of the behavioral, neuroendocrinological, physiological, neurochemical, neurological, and immunological responses found with these models, and their temporal dynamics, are discussed. Finally, the studies carried out that compare the response induced by social stress with that observed with more conventional models are also reviewed. It is concluded that these animal models of social stress have construct validity with a number of utilities. Aggr. Behav. 24:241–256, 1998.

Changes in cortisol and dehydroepiandrosterone in women victims of physical and psychological intimate partner violence

BACKGROUND Although intimate partner violence (IPV) has a great impact on womens health, few studies have assessed the consequences on physiologic responses. METHODS Women abused by their intimate male partners either physically (n = 70) or psychologically (n = 46) were compared with nonabused control women (n = 46). Information about sociodemographic characteristics, smoking, pharmacologic treatment, lifetime history of victimization (childhood and adulthood), and mental health status (depression, anxiety, and posttraumatic stress disorder, PTSD) was obtained through structured interviews. Saliva samples were collected at 8 am and 8 pm for 4 consecutive days to determine morning and evening basal levels of cortisol and dehydroepiandrosterone (DHEA). RESULTS Women who were victims of IPV had more severe symptoms of depression, anxiety, and incidence of PTSD and higher levels of evening cortisol and morning and evening DHEA compared with control women. Intimate partner violence was the main factor predicting the alterations in hormonal levels after controlling for age, smoking, pharmacologic treatment, and lifetime history of victimization. Mental health status did not have a mediating effect on the impact of IPV on hormonal levels. CONCLUSIONS This study shows that both physical and psychological IPV have a significant impact on the endocrine systems of women.

c-fos expression, behavioural, endocrine and autonomic responses to acute social stress in male rats after chronic restraint: modulation by serotonin

The effects in male rats of serotonin depletion (using the neurotoxin 5,7-dihydroxytryptamine) on the cross-sensitization of an acute social stress (defeat by a larger resident male) by previous repeated restraint stress (10 days, 60 min per day) was studied. Previous restraint increased freezing responses during social defeat in sham-operated rats, but this was not observed in those with depleted serotonin (83% or more in different regions of the brain). In contrast, neither heart rate (tachycardia) nor core temperature responses (hyperthermia) were accentuated in previously restrained rats (i.e. neither showed heterotypical sensitization), and neither adapted to repeated restraint (there is a hypothermic core temperature response during restraint). Corticosterone levels, which did adapt, nevertheless did not show accentuated responses to social defeat in previously restrained rats, though samples could only be taken 60 min after defeat. c-fos expression in the central nucleus of the amygdala 60 min after social defeat was increased by previous restraint. No other areas examined in the hypothalamus (e.g., paraventricular nucleus) or brainstem (e.g., solitary nucleus) showed differences related to previous restraint. Serotonin depletion reduced the expression of c-fos in the frontal cortex, lateral preoptic area, medial amygdala, central gray, medial and dorsal raphe, and locus coeruleus after social stress, but this was not altered by previous restraint. These results show that serotonin depletion has selective effects on the cross-sensitization of responses in previously stressed rats to a heterotypical stressor.

Effect of predatory stress on sucrose intake and behavior on the plus-maze in male mice

In this study, the effect of the exposure of male mice to sensory stimuli from rats was assessed on both sucrose intake and the elevated plus-maze tests. CDl male mice were trained in the sucrose intake task (the prestress phase) and, subsequently, distributed into two groups. The stressed group was accommodated in the same room as rats and the control group with mice (the stress phase). After being transferred, animals were tested on sucrose intake and the plus-maze (acute tests) and retested three times a week for sucrose intake and once on plus-maze on the last day (chronic tests). After acute exposure to the predator, the only difference between stressed and control animals was a higher number of fecal boli left on the plus-maze by the former. During the chronic phase, stressed animals showed a lower level of sucrose intake and higher level of anxiety than controls. In conclusion, this study shows that chronic exposure of male mice to stimuli from rats reduces the sensitivity to the rewarding properties of sucrose and prevents the habituation to the plus-maze observed in controls. Thus, this study suggests that exposure of mice to sensory stimuli from rats may provide an animal model of stress, and that these species should not be routinely housed together.

Recovery from depressive symptoms, state anxiety and post-traumatic stress disorder in women exposed to physical and psychological, but not to psychological intimate partner violence alone: a longitudinal study.

BackgroundIt is well established that intimate male partner violence (IPV) has a high impact on womens mental health. It is necessary to further investigate this impact longitudinally to assess the factors that contribute to its recovery or deterioration. The objective of this study was to assess the course of depressive, anxiety and post-traumatic stress disorder (PTSD) symptoms and suicidal behavior over a three-year follow-up in female victims of IPV.MethodsWomen (n = 91) who participated in our previous cross-sectional study, and who had been either physically/psychologically (n = 33) or psychologically abused (n = 23) by their male partners, were evaluated three years later. A nonabused control group of women (n = 35) was included for comparison. Information about mental health status and lifestyle variables was obtained through face-to-face structured interviews.ResultsResults of the follow-up study indicated that while women exposed to physical/psychological IPV recovered their mental health status with a significant decrease in depressive, anxiety and PTSD symptoms, no recovery occurred in women exposed to psychological IPV alone. The evolution of IPV was also different: while it continued across both time points in 65.21% of psychologically abused women, it continued in only 12.12% of physically/psychologically abused women while it was reduced to psychological IPV in 51.5%. Hierarchical multiple regression analyses indicated that cessation of physical IPV and perceived social support contributed to mental health recovery, while a high perception of lifetime events predicted the continuation of PTSD symptoms.ConclusionThis study shows that the pattern of mental health recovery depends on the type of IPV that the women had been exposed to. While those experiencing physical/psychological IPV have a higher likelihood of undergoing a cessation or reduction of IPV over time and, therefore, could recover, women exposed to psychological IPV alone have a high probability of continued exposure to the same type of IPV with a low possibility of recovery. Thus, women exposed to psychological IPV alone need more help to escape from IPV and to recuperate their mental health. Longitudinal studies are needed to improve knowledge of factors promoting or impeding health recovery to guide the formulation of policy at individual, social and criminal justice levels.

Intimate male partner violence impairs immune control over herpes simplex virus type 1 in physically and psychologically abused women.

Objective: Intimate partner violence (IPV) against women is a worldwide problem and a cause of significant distress and threat to health. Studies have focused mainly on mental health, and few have considered the effect on physiological systems. The aim of this research was to determine whether IPV also compromises the immune system, as evidenced by a decrease in immune regulation over herpes simplex virus type 1 (HSV-1), the latent virus that causes cold sores. Methods: Physically abused (N = 47) and psychologically abused women (N = 27) were compared with nonabused control women (N = 37). Information about sociodemographic characteristics, lifetime history of victimization, and mental health status (depression, anxiety, and posttraumatic stress disorder) was obtained through structured interviews. Salivary samples were collected on two occasions, and the capacity to neutralize live HSV-1 virus was tested with a bioassay. In addition, salivary levels of HSV-1–specific antibody and total IgA were determined by enzyme-linked immunosorbent assay. Results: Physically abused women had the lowest virus neutralization, significantly below the other two groups, with the psychologically abused group intermediate. HSV-1–specific antibody also tended to be lower in physically abused women, but these values were not directly correlated with virus neutralization, suggesting that loss of other antiviral factors accounted for the reduced bioactivity. The effect of IPV on immune function was not mediated directly by mental health status. Conclusion: These findings confirm that the stressful disturbance associated with IPV has important physiological consequences, which could impair health by increasing the likelihood of viral reactivation and reducing the ability to suppress virus proliferation. IPV = intimate partner violence; HSV-1 = herpes simplex virus type 1; PTSD = posttraumatic stress disorder; BDI = Beck Depression Inventory; STAI = Spielberger State-Trait Anxiety Inventory; CPE = cytopathologic effects; HSV-1–sIgA = specific antibody against herpes simplex virus type 1; IgA = immunoglobulin A; ANOVA = analysis of variance; EBV = Epstein-Barr virus; sIgA = secretory immunoglobulin A.

Endothelium-independent contractions of human cerebral arteries in response to vasopressin.

We studied the effects of vasopressin in isolated segments from branches (500-700 micrograms in external diameter) of human middle cerebral arteries obtained during autopsy of 15 patients who had died 3-8 hours before. Paired segments, one normal and the other de-endothelized by gentle rubbing, were mounted for isometric recording of tension in organ baths. In 11 normal segments, vasopressin produced concentration-dependent contractions with an EC50 of 7.0 X 10(-10) M. Removal of the endothelium from 12 segments did not significantly affect vasopressin-induced contractions. Vasopressin produced further contractions in arterial segments with (n = 4) or without (n = 5) endothelium precontracted with KCl. In segments precontracted with prostaglandin F2 alpha, acetylcholine choline caused relaxation only of those with endothelium. At 10(-8) M (n = 11), the vasopressin V-1 receptor antagonist d(CH2)5Tyr(Me)AVP produced a 60-fold shift to the right of the control response curve for vasopressin. Increasing the concentration of the receptor antagonist to 10(-6) M (n = 7) further displaced the control curve in a parallel manner. These results indicate that vasopressin exerts a powerful constrictor action on isolated human cerebral arteries by direct stimulation of V-1 receptors located predominantly on smooth muscle cells. It appears that this contractile response is not modulated by the presence of an intact endothelial cell layer.

Personality Disorder Symptoms in Women as a Result of Chronic Intimate Male Partner Violence

This study explores the personality disorder symptoms of women victims of intimate male partner violence (IPV), after controlling for the contribution of experiences of childhood abuse. Victims of both physical and psychological violence (n = 73) or psychological violence alone (n = 53) were compared with non-abused control women (n = 52). Information about sociodemographic characteristics, childhood abuse, and personality characteristics (MCMI-II) was obtained through face-to-face structured interviews. Women victims of IPV had higher scores than controls in schizoid, avoidant, self-defeating personality scales, as well as in the three pathological personality scales (schizotypal, borderline and paranoid). Both physical and psychological IPV were strongly associated with personality disorder symptomatology, regardless of the effects of childhood abuse. These findings underscore the need to screen for personality disorder symptoms in women victims of IPV when dealing with therapeutic interventions.

Quantification of cadmium-induced metallothionein in crustaceans by the silver-saturation method

Metallothionein (MT) has been proposed as a specific biochemical probe for metal exposure of aquatic organisms. It is recognized that its usefulness as a monitoring tool depends on the full understanding of its function and on the possibility of measuring its concentration in tissues. Therefore the study of MT in crustaceans is interesting from two different points of view: the need to understand mechanisms associated with the toxicology of metals, and the potential use of this protein for monitoring metal-contamined environments. Several methods have been developed for quantitative measurements of MT in biological samples. Immunochemical and electrochemical procedures are reliable techniques but they require sophisticated equipment and highly trained staff. In the present work, modifications to the silver-saturation method have been developed for the quantitative determination of MT in crustacean tissues, estimating silver concentrations by flame in an atomic absorption spectrophotometer. Cadmium and MT were measured both in Artemia and Procambarus clarkii after sublethal exposure to cadmium. An increase in MT content was recorded in crustacean tissues after 12 h of cadmium exposure. A high responsiveness was found in MT induction by cadmium in the two crustaceans and there was a clear relationship between cadmium concentration in water and MT levels in tissues. The silver-saturation assay may be a rapid assay technnique for biomonitoring purposes.