Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Objective measures of experimentally-induced aggressiveness were evaluated in 20 methadone-treated heroin addicts, in comparison to 20 normal healthy male subjects. All the subjects were submitted to preliminary DSM IV interviews, Buss Durkee Hostility Inventory (BDHI) and Minnesota Multiphasic Personality Inventory (MMPI II). During a laboratory task, the point subtraction aggression paradigm (PSAP), subjects earned monetary reinforcers with repeated button presses, and were provoked by the subtraction of money, which was attributed to a fictitious other participants. Subjects could respond by ostensibly subtracting money from the fictitious subject (the aggressive response), or protecting their counter (escape response). Money-earning responses were significantly lower (t=4.38, P<0.001) and aggressive responses significantly higher (t=5.45; P<0.001) in methadone patients in comparison to controls. During the experimentally-induced aggressiveness, plasma adrenocorticotropic hormone (ACTH), cortisol (CORT) and growth hormone (GH) concentrations increased significantly less and norepinephrine (NE) and epinephrine (EPI) levels, together with heart rate (HR), significantly more in methadone subjects than in healthy subjects. PSAP aggressive responses positively correlated with catecholamines changes, BDHI 'direct' and 'irritability' scores, MMPI 'psychopathic deviate' scores both in methadone subjects and controls, and with CORT responses only in healthy subjects. No correlation was found between methadone doses, or exposure extent, and aggressiveness levels. Our findings suggest that heroin dependent patients have higher outward-directed aggressiveness than healthy subjects, in relationship with monoamines hyper-reactivity, also under methadone medication. Aggressiveness in methadone patients seems to be related more to the personality traits than to drug effects. Hypothalamus-pituitary-adrenal (HPA) axis responses, unexpectedly dissociated from catecholamines rise among methadone patients, could be due to a long-lasting inhibitory action exerted by opiates on pro-opio-melanocortin (POMC), or to a premorbid psychobiological condition that exhausted hormonal reactivity.
 ...
PMID:Aggressive responding of male heroin addicts under methadone treatment: psychometric and neuroendocrine correlates. 1171 93

Because of welfare concerns and increased labor efficiency, calves are increasingly housed in groups. To reduce variability in live weight within groups, farmers frequently regroup calves according to growth rate. We assessed the consequences of repeated regrouping and relocation on the welfare of 32 male Holstein calves housed in pairs. Animals of half of the pairs (regrouped calves) were placed in a new pen with a new partner once a week for 14 wk. Animals of the other half of the pairs (control calves) stayed in the same pen with the same partner. Behavior was observed for the 3 h following four mixings and for 24 h after all relocations were finished. The functioning of the hypothalamic-pituitary-adrenal axis and of the sympathetic nervous system were assessed. Calves were weighed once a week, their health was assessed daily, and abomasa were inspected when the calves were slaughtered. Calves reacted to the first mixing by interacting with the new partner and increasing their general activity (sniffing the partner in regrouped calves vs controls: 5.5 vs 2.9, P < 0.01; percentage time stepping: 3.2 vs 1.3, P < 0.001). This effect disappeared by the ninth mixing. After all relocations were completed, regrouped calves were more active at the end of the day and less active at night (P < 0.05). Cortisol responses to exogenous ACTH were higher in regrouped calves (integrated response: 6,688 vs 5,508 ng x min/mL, P < 0.01). Basal cortisol levels, ACTH responses to corticotropin-releasing hormone, activities of catecholamine-synthesizing enzymes (tyrosine hydroxylase and phenylethanolamine N-methyl transferase), and the incidence of health problems and growth rates did not differ between the two groups. Regrouped calves had fewer abomasal ulcers. Apart from the increased sensitivity of the adrenal cortex of regrouped calves to ACTH and the modification in the daily rhythm of activity, there was no clear evidence that repeated regrouping and relocation stresses calves. Aggression between calves was rare, and calves seemed to habituate to repeated mixing.
 ...
PMID:Calves' responses to repeated social regrouping and relocation. 1172 37

Blunted neuroendocrine responses to stress are reported in lactating females after exposure to various stressors. However, many of the stimuli used in these studies have little ethological relevance for maternal protection of the litter in a threatening environment. The question that arises is whether the relevance of the stressor to the infant is critical in the 'gating' of the neuroendocrine response. We hypothesized that the presence of pups with their mothers at the time of exposure to an intruder or a predator odour is an effective way to increase the emotional salience of the psychological stressor, thus eliminating the stress hyporesponsiveness in lactating females. We first compared neuroendocrine responses [corticotropin-releasing factor (CRF) mRNA in the paraventricular nucleus of the hypothalamus (PVN) and central nucleus of the amygdala (CeA), plasma adrenocorticotropic hormone (ACTH) and corticosterone] between early (EL, PPD3-5), late (LL, PPD 15) lactating and virgin (V) females to a male intruder in the home cage. We next investigated the effect of pups' presence at the time of stressor exposure on the magnitude of the hormonal response to a male intruder in the home cage or to a predator odour (fox urine) in a novel environment. In the male intruder paradigm, levels of CRF mRNA expression in the PVN and CeA were lower in LL compared to EL or V females and plasma ACTH and corticosterone secretion was not as elevated in LL compared to EL females. Aggression towards the intruder was high in EL females in the presence of their pups and a positive correlation was found with the integrated ACTH response. Aggression rapidly declined after pup separation (2.5 h or 48 h) or in LL nursing females. In EL females, the presence of the pups with their mothers (EL + pups) at the time of stress significantly increased plasma ACTH and corticosterone responses to either male intruder or predator odour compared to EL females without their pups for 2.5 h or 48 h (EL - pups). Plasma ACTH response to fox urine in EL + pups females was comparable to that of virgin females, suggesting that increasing the salience of emotionally relevant stimuli by keeping the pups present in the cage could eliminate the hyporesponsiveness detected for EL females without their pups. These studies indicate the critical role of the pups in modulating the maternal response to stressors that represent a threat for the litter. We hypothesize that the amygdala, because of its ability to process olfactory stimuli and stimuli with affective properties, might play an essential role in 'gating' the neuroendocrine response to stress during lactation.
 ...
PMID:Pups presence eliminates the stress hyporesponsiveness of early lactating females to a psychological stress representing a threat to the pups. 1269 74

Beta-endorphin is an endogenous opioid peptide that is released during stress and has been associated with many physiological functions. In this experiment beta-endorphin deficient mice were used to study the role of endorphins in the acute physiological and behavioral responses to a social conflict, as well as their role in social stress-induced changes in sleep. Adult male beta-endorphin deficient and wild type mice were subjected to the stress of a 1 h social conflict with an aggressive dominant conspecific. After the conflict, the beta-endorphin deficient mice had higher corticosterone levels but the peak increase in body temperature was not different from that in wild type animals. In fact, body temperature returned to baseline levels faster in the beta-endorphin deficient mice. During their interaction with the aggressive conspecific several of the beta-endorphin deficient mice showed clear signs of counter aggression whereas this was not seen in any of the wild type mice. Overall, the beta-endorphin deficient mice and wild type mice had fairly similar sleep patterns under baseline conditions and also showed similar amounts of NREM sleep, REM sleep and EEG slow-wave energy after the social conflict. In addition, no differences were found in the sleep patterns of mice that showed counter aggression and mice that did not. In conclusion, the results suggest that beta-endorphin modulates the acute endocrine, thermoregulatory and behavioral response to a social conflict but the data do not support a major role for beta-endorphin in the regulation of sleep or social stress-induced alterations in sleep.
 ...
PMID:Beta-endorphin modulates the acute response to a social conflict in male mice but does not play a role in stress-induced changes in sleep. 1283 11

The stress system orchestrates body and brain responses to the environment. This action exerted by the mediators of the stress system has two modes of operation. The immediate response mode driven by corticotropin-releasing hormone (CRH) organises via CRH-1 receptors the behavioural, sympathetic and hypothalamic-pituitary-adrenal (HPA) responses to a stressor. In the other - slower - mode, which facilitates behavioural adaptation, the urocortins acting through CRH-2 receptors seem prominent. Corticosteroid hormones secreted by the adrenal cortex are implicated in both modes through their high affinity type 1 (mineralocorticoid receptors - MR) and lower affinity type 2 (glucocorticoid receptors - GR) receptors that are co-localised in limbic neural circuitry. Current data suggest that MR controls in specific afferents the threshold or sensitivity of the fast CRH-1 driven stress system mode and thus prevents disturbance of homeostasis, while GR facilitates its recovery by restraining in these very same circuits stress responses and by mobilising energy resources. In preparation for future events GR facilitates behavioural adaptation and promotes storage of energy. The balance in the two stress system modes is thought to be essential for cell homeostasis, mental performance and health. Imbalance induced by genetic modification or chronic stressors changes specific neural signalling pathways underlying psychic domains of cognition and emotion, anxiety and aggression. This Yin-Yang stress concept is fundamental for genomic strategies to understand the mechanistic underpinning of cortisol-induced stress-related disorders such as i.e. severe forms of depression and co-morbid diseases.
 ...
PMID:Hormones, brain and stress. 1293 91

Previous studies suggest that brain opioid activity decreases aggression in animal models. The main objective of the current study was to examine the possible genetic relationship between intermale aggression and brain levels of enkephalins, endorphins, and dynorphins in 11 inbred strains of mice. Pursuit, rattling, and attack behaviors were observed in a dyadic encounter with a standard opponent. It appeared that, as expected, enkephalins and endorphins were always negatively correlated with aggression scores. The findings indicate that brain Met5-enkephalin levels were significantly and highly positively correlated with attack latency. Brain adrenocorticotrophic hormone (ACTH) and beta-endorphin levels were significantly and negatively correlated with the number of rattlings, which is consistent with the hypothesis that rattling is a stress-related behavior. In contrast with Met5-enkephalin, ACTH and beta-endorphin, the correlations between dynorphin A and aggression scores were nonsignificant and very low. These preliminary results suggest that common genetic sources of variation contribute to differences between the 11 inbred strains in both endogenous opioidergic systems and intermale aggression. Further studies are required to confirm the genetic relationship between offensive aggression and brain enkephalins and endorphins and to better understand the mechanisms underlying the role of endogenous opioids in offensive aggression with regard to opioid receptor activity.
 ...
PMID:Aggression and the three opioid families (endorphins, enkephalins, and dynorphins) in mice. 1457 30

Oral contraceptives (OCs) are the most widely prescribed and effective of the reversible contraceptive methods. In addition to inhibiting ovulation, OCs alter central nervous system function in women; however, methodological problems have prevented clear human studies. Thus, in this experiment we investigated the effects of OC treatment on behavior, hypothalamic- pituitary-adrenal axis function and the central nervous system in 75 adult female cynomolgus monkeys (Macaca fascicularis) housed in social groups of four to five monkeys per pen. Monkey social groups were randomly divided into either a control or an OC treatment group which was administered a clinically prescribed OC (Triphasil(R), levonorgestrel and ethinyl estradiol tablets) for 2 years. OC treatment increased the frequency of contact aggression received, time spent in locomotion, and sitting close to another animal, and decreased time spent fearfully scanning. OC treatment decreased heart rate, increased activity levels, and increased baseline cortisol concentrations and the cortisol response to adrenocorticotropin compared to control animals. OC treatment decreased the prolactin response to fenfluramine suggesting decreased serotonergic activity. These results suggest that this triphasic OC disrupts social behavior, hypothalamic-pituitary-adrenal axis regulation and the underlying central nervous system function.
 ...
PMID:Triphasic oral contraceptive treatment alters the behavior and neurobiology of female cynomolgus monkeys. 1457 27

A brief exposure to social defeat in male Syrian hamsters (Mesocricetus auratus) leads to profound changes in the subsequent agonistic behavior exhibited by the defeated animals. Following defeat in the home cage of an aggressive conspecific, male hamsters will subsequently fail to defend their home territory even if the intruder is a smaller, nonaggressive male. This phenomenon has been called conditioned defeat. In Experiment 1, we examined the duration of conditioned defeat by repeatedly testing (every 3-5 days) defeated hamsters with a nonaggressive intruder. We found that conditioned defeat occurs in all defeated male hamsters and persists for a prolonged period of time (at least 33 days) in the majority of male hamsters tested despite the fact that these animals are never attacked by the nonaggressive intruders. In Experiment 2, we examined whether conditioned defeat could be induced in female Syrian hamsters. While conditioned defeat occurred in some females, they displayed only low levels of submissive/defensive behavior and, in contrast to males, the conditioned defeat response did not persist beyond the first test. These results suggest that in male hamsters conditioned defeat is a profound, persistent behavioral change characterized by a total absence of territorial aggression and by the frequent display of submissive and defensive behaviors. Conversely, social defeat in female hamsters does not appear to induce long-term behavioral changes. Finally, in Experiment 3, we determined that plasma adrenocorticotropin-like immunoreactivity increases in females following social defeat in a manner similar to that seen in males, suggesting that the disparate behavioral reactions of males and females are not due to sex differences in the release of, or response to, plasma adrenocorticotropin.
 ...
PMID:Conditioned defeat in male and female Syrian hamsters. 1460 51

Objective measures of experimentally induced aggressiveness were evaluated in 20 abstinent heroin-dependent subjects, in comparison with 20 normal healthy male subjects. All the subjects were preliminarily submitted to DSM-IV interviews, Buss-Durkee Hostility Inventory (BDHI) and Minnesota Multiphasic Personality Inventory (MMPI II). During a laboratory task, the Point Subtraction Aggression Paradigm (PSAP), subjects earned monetary reinforcers with repeated button presses and were provoked by the subtraction of money, which was attributed to a fictitious other participant. Subjects could respond by ostensibly subtracting money from the fictitious subject (the aggressive response). Money-earning responses were not different in drug-free heroin addicts and controls during the first two sessions and significantly lower during the third session in heroin-dependent subjects (t=2.99, P<.01). Aggressive responses were significantly higher (F=4.9, P<.01) in heroin addicted individuals, in comparison with controls. During the experimentally induced aggressiveness, plasma adrenocorticotropic hormone (ACTH) and cortisol (CORT) concentrations increased less significantly, and norepinephrine (NE) and epinephrine (EPI) levels, together with heart rate (HR), increased more significantly in abstinent heroin-dependent subjects than in healthy subjects. PSAP aggressive responses positively correlated with catecholamine changes, BDHI "direct" and "irritability" scores, MMPI "psychopathic deviate" scores in heroin-dependent subjects and controls, and with CORT responses only in healthy subjects. No correlation was found between heroin-exposure extent (substance abuse history duration) and aggressiveness levels. The present findings suggest that heroin-dependent patients have higher outward-directed aggressiveness than healthy subjects, in relation with monoamine hyperreactivity, after long-term opiate discontinuation. Aggressiveness in heroin addicts seems to be related more to the personality traits than to drug effects. The impairment of hypothalamus-pituitary-adrenal (HPA) axis in abstinent addicted individuals could be due to a long-lasting action exerted by opiates on proopiomelanocortin (POMC) or to a premorbid psychobiological condition, in association with increased sympathetic arousal.
 ...
PMID:Aggressive responding in abstinent heroin addicts: neuroendocrine and personality correlates. 1468 67

Variations in the human mu-opioid receptor gene have driven exploration of their biochemical, physiological and pathological relevance. We investigated the existence of variations in the nonhuman primate mu-opioid receptor gene to determine whether nonhuman primates can model genotype/phenotype associations of relevance to humans. Similar to the A118G single nucleotide polymorphism (SNP) in the human mu-opioid receptor gene, a SNP discovered in the rhesus monkey mu-opioid receptor gene (C77G) alters an amino acid in the N-terminal arm of the receptor (arginine for proline at position 26). Two mu-opioid receptor coding regions isolated from a single heterozygous (C77/G77) rhesus monkey brain were expressed in HEK-293 cells and characterized in radioreceptor assays. Paralleling the findings of increased affinity of beta-endorphin by the A118G allele in the human, the rhesus monkey mu-opioid receptor protein derived from the G77-containing clone demonstrated a 3.5-fold greater affinity for beta-endorphin than the receptor derived from the C77-containing clone. An assay developed to assess the incidence of the C77G SNP in a behaviorally and physiologically characterized cohort of rhesus monkeys (n=32) indicated that 44% were homozygous for C77-containing alleles, 50% were heterozygous and 6% were homozygous for G77-containing alleles. The presence of G77-containing alleles was associated with significantly lower basal and ACTH-stimulated plasma cortisol levels (P<0.03-0.05 and P<0.02, respectively) and a significantly higher aggressive threat score (P<0.05) in vivo. In a cohort of 20 monkeys, a trend towards an inverse correlation between aggressive threat and plasma cortisol levels was observed. The findings suggest that mu-opioid receptor haplotypes in monkeys can contribute to individual variability in stress response and related aggression. The data support the use of nonhuman primates to investigate mu-opioid receptor genotype/phenotype relations of relevance to humans.
 ...
PMID:A mu-opioid receptor single nucleotide polymorphism in rhesus monkey: association with stress response and aggression. 1469 47


<< Previous 1 2 3 4 5 6 7 8 Next >>