Role Of HPA Axis Research Articles

Hypothalamus-pituitary-adrenal Axis in Glucolipid metabolic disorders.

With the change of life style, glucolipid metabolic disorders (GLMD) has become one of the major chronic disorders causing public health and clinical problems worldwide. Previous studies on GLMD pay more attention to peripheral tissues. In fact, the central nervous system (CNS) plays an important role in controlling the overall metabolic balance. With the development of technology and the in-depth understanding of the CNS, the relationship between neuro-endocrine-immunoregulatory (NEI) network and metabolism had been gradually illustrated. As the hub of NEI network, hypothalamus-pituitary-adrenal (HPA) axis is important for maintaining the balance of internal environment in the body. The relationship between HPA axis and GLMD needs to be further studied. This review focuses on the role ofHPA axis in GLMD and reviews the research progress on drugs for GLMD, with the hope to provide the direction for exploring new drugs to treat GLMD by taking the HPA axis as the target and improve the level of prevention and control of GLMD.

Role of HPA axis on the development of ethanol dependence in mice

Role of HPA axis on the development of ethanol dependence in mice

Acute Stress Induced Behavioral Deficits In Rats: Relationship With Oxidative Stress, Leptin And HPA Axis

Acute exposure to stress is connected to many disorders that promote the toxicity of oxygen radical generators leading to increase in the levels of enzymes and also the activation of the HPA axis. The present study uses a preclinical approach to elucidate some prospective stress-induced behavioral and biochemical effects. The aim of current study was to investigate the relationship between stress and behavioral changes after exposing animals to 2h immobilization stress. We also evaluated the concentration of corticosterone, glucose and endogenous leptin levels in unstressed and stressed animals to explore the possible role of HPA axis in the modulation of stressed induced behavioral deficits. Rats were divided into stressed and unstressed groups. Behavioral activities were monitored in open field activity and light dark transition box after the termination of 2h immobilization period. Animals were then decapitated and plasma samples were collected for catalase, SOD, corticosterone, and glucose estimation. Results showed that exposure to acute stress produced a significant decrease in the activity of rats in the novel environment (open field) and light dark transition box. On the other hand, concomitant elevated level of peripheral markers of oxidative stress such as oxidative enzymes, corticosterone and endogenous leptin were also observed. Therefore, current study seems to suggest an important role of compounds having antioxidant properties for the treatment of stress and related disorders.

Hypothalamus-pituitary-adrenal (HPA) axis parameters and neurocognitive evaluation in patients with bipolar disorder.

Bipolar disorder is associated with neurocognitive impairment but the etiology of such impairment remains largely unknown. The present study aimed at investigating the performance of bipolar patients in various neuropsychological tasks within the framework of HPA axis hyperactivity model and also the impact of disease characteristics on neuropsychological functioning. Cognitive performance of 60 bipolar-I patients and 30 healthy controls was evaluated by using tasks from the CANTAB battery targeting visual memory, executive function and inhibitory control. Current symptoms were evaluated via administration of the Hamilton Depression Rating Scale (HAMD) and Young Mania Rating Scale (YMRS) whereas assessment of functioning was performed with the Global Assessment of Functioning (GAF). Basal cortisol levels were determined and all patients were administered the Dexamethasone Suppression Test (DST). Statistically significant differences between patients and controls were found in visuo-spatial associative learning and memory, planning, attentional set shifting and inhibitory control. Worse performance in visuospatial associative memory correlated with longer duration of illness and higher levels of basal cortisol. Poorer attentional set shifting was related to higher number of manic episodes. We found no relationship of neurocognitive measures with DST suppression status, current symptom severity or history of psychosis. The results of our study confirm the presence of cognitive deficits in bipolar disorder and provide evidence on the relation of cortisol with neuropsychological functioning, especially visuo-spatial associative memory. Moreover, we have found that number of previous manic episodes and duration of illness is associated with worse cognitive performance. It is known that neurocognitive deficits are evident in many patients with bipolar disorder. These deficits are often a cause of considerable distress and can lead to impairment of psychosocial and occupational functioning. The role of HPA axis needs to be further examined in bipolar disorder. Nevertheless, the identification of factors affecting neurocognitive functioning, like basal cortisol and number of manic episodes, may contribute to the implementation of more appropriate prevention strategies.

The efficacy of prednisone in the treatment of infantile spasm and HPA axis mechanism analysis

Objective By studying the changes of the seizures of infantile spasm (IS)、EEG and HPA axis function before and after the treatment of prednisone, to explore the efficacy of prednisone in treating infantile spasm, the role of HPA axis in the pathogenesis of IS, and elucidate the HPA axis mechanism of prednisone in controling seizure. Methods A total of 30 patients with IS (IS group) and 30 cases of healthy infants and young children (control group) were recruited.Number of seizures、EEG 、HPA axis function was detected before and after the treatment of prednisone in patients with infantile spasm.Serum cortisol, ACTH were determined by the chemiluminescence analysis, serum CRH was measured by enzyme-linked immunosorbent assay. Results serum CRH levels of IS group was significantly higher than normal control group(P 0.05). The average number of daily ictal clusters and the average daily total seizure number positively correlated with CRH respectively.After the application of the prednisolone, seizure of 19 cases of the IS were controlled, 11 cases were not controlled, 18 cases of hyperarrhythmia were completely remited and 12 cases of hyperarrhythmia were not completely remited.The average number of daily ictal clusters and The average daily total seizure number after treatment were significantly lower than before treatment(P<0.05); DQ after treatment was higher than DQ before treatment(P<0.05); The pathogenesis was the main influencing factor of the prednisone treatment effect, the length of the disease, the worse the treatment(P<0.05). CRH、cortisol、ACTH after treatment were significantly lower than before treatment(P<0.05). Conclusion Prednisone can effectively control the onset of infantile spasms, and early treatment is better.IS patient has HPA axis dysfunction, and prednisone can regulate HPA axis dysfunction to control spasm. Key words: Infantile spasm; HPA axis; Prednisone

Potential Role of HPA Axis and Sympathetic Nervous Responses in Depletion of B Cells Induced by H9N2 Avian Influenza Virus Infection

Except severe pulmonary disease caused by influenza virus infection, an impaired immune system is also a clinic characteristic. However, the mechanism(s) of influenza virus infection-induced depletion of B cells was unknown. Here, we compared the effect of two variant virulence H9N2 virus infections on mouse B cells. Our study found that the infection with highly pathogenic virus (V) of led to depletion of spleen B cells and bone marrow (BM) early B cells, compared to lowly pathogenic virus (Ts). Moreover, high apoptosis and cell cycle arrest in spleen and BM were detected, suggesting important factors for the reduction of B cells in both organs. Further, this effect was not caused by virus replication in spleen and BM. Compared to Ts virus infection, V virus resulted in higher glucocorticoids (GCs) and lower leptin level in plasma. Intraperitoneal GCs receptor antagonist RU486 injection was sufficient to prevent the loss of spleen B cell and BM pro- and immature B cells, but similar result was not observed in leptin-treated mice. Depletion of spleen B cells and BM pro-B cells was also reversed by chemical sympathectomy mediated by the norepinephrine (NE) analog 6-hydroxydopamine (6-OHDA), but the treatment didn't affect the GCs level. This study demonstrated that depletion of B cells induced by H9N2 AIV was dependent on HPA axis and sympathetic response.

Acute cold-induced thermogenesis in neonatal chicks ( Gallus gallus)

Mechanisms of thermogenic responses that play a role to maintain homeothermy during an early stage of neonatal chicks on acute cold exposure are scarcely studied as hatchlings are believed to be poikilothermic. However, chicks can attain the homeothermy during their subsequent growth after hatching. To identify thermogenic responses during neonatal stages of chicks ( Gallus gallus) on acute cold exposure (12 °C, 3 h), changes in plasma corticosterone levels, thermogenesis, gene transcripts (avUCP and avPGC1α) in skeletal muscles ( pectoralis superficialis and gastrocnemius) and mitochondrial substrate oxidation enzyme activities in dissected tissues of 1- and 4-d-old chicks were studied. Results revealed that 1-day-old neonatal chicks were particularly vulnerable to cold exposure and were hypothermic. However, 4-d-old cold-exposed chicks maintained thermostability with significantly higher plasma corticosterone levels, oxygen consumption, heat production, and increased mitochondrial substrate oxidation enzyme activities (CS and 3HADH) in different dissected tissues. Analysis of gene transcripts for avian peroxisome-proliferator-activated receptor-γ co-activator-1α (avPGC1α) and avian uncoupling protein (avUCP) in skeletal muscles revealed no significant change between cold-sensitive (1-d-old) and cold-tolerant (4-d-old) neonatal chicks, and failed to explain the enhanced thermogenesis and tolerance to acute cold. Additionally, avPGC1α gene transcripts were not correlated with the increased enzyme activities of CS or 3HADH in skeletal muscle. In conclusion, these data suggest the possible role of HPA-axis in cold-tolerant neonatal chicks to modulate substrate mobilization and oxidation. The thermogenic mechanisms based in part upon the increased capacity for mitochondrial substrate oxidation in different tissues are associated with enhanced heat production to attain homeothermy and acquire tolerance to acute cold exposure during an early stage of neonatal chicks.

Involvement of hypothalamic pituitary adrenal axis on the nifedipine-induced antinociception and tolerance in rats

Nifedipine, a calcium channel blocker, can modulate the nociceptive threshold. However, the underlying mechanism, especially the role of HPA axis, on this effect has still not been elucidated. In the present study we investigated the analgesic effect of nifedipine in intact and adrenalectomized (ADX) male rats and we also measured the effect of nifedipine on HPA function. The Tail-Flick test was used to assess the nociceptive threshold before and 15, 30, 60, 90, and 120 min after drug administration. Corticosterone level was measured by radioimmunoassay as a marker of HPA function. Our results showed that in intact and sham operated animals, administration of 10 mg/kg nifedipine induces an antinociceptive effect. But at the dosage of 2 and 5 mg/kg animals do not exhibit this effect. With repeated injections, its analgesic effect was decreased, a phenomenon prevented by adrenalectomy. Acute administration of nifedipine produced significant decrease in plasma corticosterone level. In ADX animals, had a potent antinociceptive effect nifedipine at high dosage (10 mg/kg) as well as at lower dosage (5 mg/kg) that reversed with corticosterone replacement. In conclusion, the results of our study show that the elimination of HPA function through adrenalectomy potentiates the antinociceptive effect of nifedipine and attenuates its analgesic tolerance. Both effects are reversed by corticosterone replacement.

Involvement of hypothalamic pituitary adrenal axis on the effects of nifedipine in the development of morphine tolerance in rats

It has been shown that nifedipine, as a calcium channel blocker, can attenuate the development of tolerance to the antinociceptive effect of morphine; however, the role of HPA axis on this action has not been elucidated. We examined the effect of nifedipine on morphine analgesic tolerance in intact and adrenalectomized (ADX) rats and on HPA activity induced by morphine. Adult male rats were rendered tolerant to morphine by daily injection of morphine (15 mg/kg i.p.) for 8 days. To determine the effect of nifedipine on the development of morphine tolerance, nifedipine (1, 2 and 5 mg/kg i.p.) was injected concomitant with morphine. The tail-flick test was used to assess the nociceptive threshold, before and 30 min after morphine administration in days 1, 3, 5 and 8. Our results showed that despite the demonstration of tolerance in both ADX and sham operated rats, nifedipine in ADX rats prevented morphine tolerance development at a lower dose (2 mg/kg) than in sham operated rats, however corticosterone replacement prevented nifedipine effect in ADX rats. Acute administration of morphine produced significant increase in plasma corticosterone level, and with repeated injection, a tolerance to this neurosecretory effect was developed. Nifedipine (5 mg/kg) attenuated the acute effect of morphine, but could not block its neurosecretory tolerance.

34-1 - Role of HPA axis in the modulation of brain and plasma neurosteroid content elicited by stress and benzodiazepine receptor ligands

34-1 - Role of HPA axis in the modulation of brain and plasma neurosteroid content elicited by stress and benzodiazepine receptor ligands