Stress-related hormonal and psychological changes to official youth Taekwondo competitions.

The aim of this study was to evaluate the effects of an official Taekwondo competition on the heart rate (HR), salivary α-amylase (sA-A), salivary free cortisol (sC), and Profile of Mood States (POMS) in 10 young male (14±0 years) and six female (13±1 years) athletes. POMS and hormones were measured 15 min before and directly after the competition. During the recovery phase (30 and 90 min), sA-A and sC were also measured. HR measured during the competition was expressed as a percentage of individual's maximal heart rate (%HR(max) ) to evaluate the intensity of exercise. During the competition, athletes spent 65% of the time working at HR>90% of individuals HR(max). A significant increase (P<0.0001) in sA-A (115%) was observed at the end of the match. At 30 min of recovery, sA-A returned to the pre-competition level. The peak sC values were observed at 30 min of recovery (P<0.001), returning to the pre-competition level at 90 min of recovery. A gender difference (P=0.01) emerged only for sC, although a similar trend was observed for female and male athletes. Significantly higher post-match scores emerged for Anger-hostility (pre: 6.1±1.1, post: 11.2±1.9; P=0.03) and Depression-dejection (pre: 4.5±0.5, post: 10.2±1.9; P=0.006), whereas the reverse picture was observed for Vigour-activity (pre: 23.2±1.2, post: 16.3±1.7; P=0.0006). Taekwondo competition results in temporary changes in the stress-related parameters measured in this study. The present findings suggest that this experimental paradigm can represent a useful model for further research on the effects of various stressors (i.e., training and competition) in Taekwondo athletes of different levels (i.e., novice, international).

Risk and indicators of condemnation of male turkey broilers in western France, February-July 2006.

A field study was conducted to estimate the sanitary condemnation proportion in male turkey broiler flocks, to describe the reasons for condemnation and the related macroscopic lesions, and to investigate whether primary production information would predict the risk of condemnation. Male turkey standard broiler flocks (117) were randomly selected in the 13 slaughterhouses located in Western France, from February to July 2006. The flocks were monitored from their arrival at the slaughterhouse until the results of the post mortem sanitary inspection. Information about rearing conditions, health history, catching and loading conditions, transportation to the slaughterhouse and slaughtering was also collected. Sampling design was considered in the calculations and the condemnation proportion was modelled using a negative binomial regression, accounting for clustering within slaughterhouse. The within-flock weighted average condemnation proportion was 1.8% (95% confidence interval, 1.3-2.3%). Emaciation, arthritis-polyarthritis and congestion were the main reported official reasons for condemnation, representing 76% of the condemned carcases. Three variables were significantly associated with increased risk of condemnation: observed locomotor disorders on the farm, high cumulative mortality 2 weeks before slaughter, and clinical signs observed by the Veterinary Services during the ante mortem inspection at the slaughterhouse. The final model explained 35% of the total variation in condemnation risk. Half of this explained variation could be attributed to locomotor disorders observed during rearing. The sensitivity and specificity of the model to predict a high flock condemnation risk were 80% and 74%, respectively, when using an optimum threshold of 0.95% to define high risk. The results of this study suggested that the variables found to be associated with condemnation proportion were markers of increased risk and could be used as indicators. These risk indicators can easily be retrieved from the pre-existing regulatory document transmitted before flock arrival at the slaughterhouse and could be used to screen flocks before slaughter, according to their expected risk of condemnation.

Immune and endocrine aspects of social and territorial behavior in male rabbits.

Although there have been some studies of the relation between behavior and mitogen-induced lymphocyte proliferation and immunoglobulin synthesis, few data are available about the effect of behavior on specific lymphokine production. In this study, we describe the effect of social and territorial behaviors on interferon-gamma (IFN-gamma) production by concanavalin A-stimulated peripheral blood mononuclear cells (PBMCs) in pairs of socially naive male rabbits living in a seminatural open-air environment. We also assayed PBMC glucocorticoid receptors (GcRs) and plasma corticosterone (C). Three groups of behaviors were identified: agonistic (Mount and Follow), affiliative (Groom) and territorial (Mark and Dig). Mount was correlated with Follow, while Mark was correlated with Dig. Groom was correlated with all the other behaviors. Groom, Mark, Mount and Follow were all positively correlated with PBMC GcRs. Groom and PBMC GcRs were each negatively correlated with plasma C. The two rabbits in each pair could be distinguished in terms of territorial behavior, since one animal always had a higher score. The animals with the higher level of territorial behavior within the pairs exhibited a significant increase in IFN-gamma production at the end of the experimental period. They also showed a positive correlation between the percentage variations of IFN-gamma production and PBMC GcRs. It is suggested that social factors, especially territorial behavior, affect adrenocortical activity and IFN-gamma production.

Immune and neuroendocrine response to restraint in male and female rats.

A parallel study of the modification in the opioid and immunological systems induced by acute restraint (RT) was carried out in male and female rats 24 hr after the treatment. beta-Endorphin-like immunoreactivity (beta-ELI) was measured in two brain areas (ventral hypothalamus [HYP] and periaqueductal gray matter [PAG]) and in the pituitary (anterior and neurointermediate lobes), together with plasma corticosterone (C) and ACTH. Immune function was measured as mitogen-induced Interferon-gamma (IFN-gamma) production by splenocytes. RT reduced beta-ELI levels in the PAG in males and females. Plasma levels of C and ACTH did not differ from the basal levels in restrained animals. RT reduced IFN-gamma production in both sexes, but this effect was more marked in females than in males. The possible relationship between the immune and opioid system is discussed.

The effect of medial preoptic-anterior hypothalamic lesions on testosterone plasma levels and testosterone conversion in the hypothalamus of male rats.

Male Wistar rats were submitted to bilateral high frequency lesions in the medial preoptic-anterior hypothalamic area or to sham procedure. The behavioral effect of the lesions was observed and plasma testosterone (T) and estradiol (E2) were measured by radioimmunoassay. In vitro metabolism of T was studied in the hypothalamus. Lesions produced a permanent deficit in male sexual behavior, an increase of plasma T and E2, and of hypothalamic T aromatization, and a decrease of T conversion to 5 alpha-dihydrotestosterone (DHT).

Effect of castration on hypothalamic testosterone metabolism in the male rat.

In vitro studies were performed of hypothalamic testosterone (T) metabolism 30 days after castration of adult male rats. No changes were seen in T conversion into dihydrotesterone and estrogens in the castrated rats. Plasma T levels were decreased while plasma estradiol concentrations did not differ from those of intact controls. It was suggested that the hypothalamic T metabolism probably is not androgen dependent.

Odour of male and female rats changes hypothalamic aromatase and 5 alpha-reductase activity and plasma sex steroid levels in unisexually reared male rats.

Male rats between 25--65 days of age were reared under four different social conditions: (1) In cohabitation with only males; (2) as in (1), but exposed to bedding from a cage containing other males; (3) as in (1), but exposed to bedding of females; (4) in cohabitation with both males and females. At 65 days of age the animals were killed and analyzed for plasma levels of testosterone and estradiol and in vitro studies were undertaken of hypothalamic testosterone metabolism. Males reared in absence of females showed lowered testosterone and estradiol plasma concentrations and increased hypothalamic aromatase and 5 alpha-reductase activity compared to heterosexually reared males. The effects of cohabitation with males only were counteracted by exposure to bedding of other males or of females suggesting an importance of odoriferous stimuli associated with sexually mature males and females during the sexual maturation of the male rat.