Thursday, 19 December 2013

The Effects of Adrenocorticotropic hormone (1)

Adrenocorticotropic hormone (ACTH) or corticotropin, is a  hormone produced by the anterior pituitary gland in response to biological stress by effecting the increased production and release of corticosteroids(a)

1. Stress-induced corticotropin-releasing hormone-mediated NLRP6 inflammasome inhibition and transmissible enteritis
Stress alters brain-gut interactions and could exacerbate intestinal disorders, including irritable bowel syndrome. Alterations in the intestinal microbiota have been associated with irritable bowel syndrome.
In the study to mice that were not exposed to stress were co-housed with mice subjected to WAS to determine the effects of WAS-induced dysbiosis, measured by sequencing bacterial 16S ribosomal RNA. We also assessed the effects of a peroxisome proliferator-activated receptor-γ agonist and probiotics, found that mice expose to stress inhibits NLRP6 and alters the composition of the gut microbiota, leading to intestinal inflammation. These findings might explain the benefits of probiotics for patients with stress-associated gastrointestinal disorders(1).

2. Corticotropin-releasing hormone in depression and post-traumatic stress disorder
Corticotropin-releasing hormone (CRH) has been implicated in the regulation of a wide range of behaviors including arousal, motor function, feeding, and reproduction.  According to the study by the Cincinnati VAMC, Psychiatry Service, overall, the data suggest that melancholic depression is characterized by hyperactive central CRH systems with overactivity of the pituitary-adrenal (HPA) axis. On the other hand, atypical depression is characterized by hypoactive central CRH systems and accompanying underactivity of the hypothalamic-pituitary-adrenal axis. Furthermore, the neuroendocrinology of PTSD appears to be unique, in that patients have hyperactive central CRH systems with underactivity of the pituitary-adrenal axis(2).

3. Early-life stress-induced anxiety-related behavior in adult mice 
Early-life stress may lead to persistent changes in central corticotropin-releasing hormone (CRH) and the CRH receptor 1 (CRHR1) system that modulates anxiety-related behavior. In the study used conditional forebrain CRHR1 knockout (CRHR1-CKO) mice and examined the potential role of forebrain CRHR1 in the anxiogenic effects of early-life stress, indicated that as adults, wild-type mice that received unstable maternal care during the first postnatal week showed reduced body weight gain and increased anxiety levels in the open field test, which were prevented in stressed CRHR1-CKO mice. In the light-dark box test, control CRHR1-CKO mice were less anxious, but early-life stress increased anxiety levels in both wild-type and CRHR1-CKO mice. In the elevated plus maze test, early-life stress had only subtle effects on anxiety-related behavior. Moreover, early-life stress did not alter the basal home cage activity and gene expression levels of key hypothalamic-pituitary-adrenal axis regulators in adult wild-type and CRHR1-CKO mice, but enhanced neuroendocrine reactivity to acute immobilization stress in CRHR1-CKO mice(3).

4. Stress and Visceral Pain: Focusing on Irritable Bowel Syndrome
Irritable bowel syndrome (IBS) is characterized by chronic recurrent abdominal pain or abdominal discomfort associated with bowel dysfunction. According to the study by the Tohoku University Graduate School of Medicine Sendai, it is also thought to be a disorder of the brain-gut link associated with an exaggerated response to stress. Corticotropin-releasing hormone (CRH), a major mediator of the stress response in the brain-gut axis, is an obvious candidate in the pathophysiology of IBS. Indeed, administration of CRH has been shown to aggravate the visceral sensorimotor response in IBS patients and the administration of peptidergic CRH antagonists seems to alleviate IBS pathophysiology. Serotonin (5-HT) is another likely candidate associated with brain-gut function in IBS since 5-HT3 antagonists, 5-HT4 agonists, and antidepressants were demonstrated to regulate 5-HT neurotransmission in IBS patients. Autonomic nervous system function, the neuroimmune axis, and the brain-gut-microbiota axis show specific profiles in IBS patients(4).

5. Role of corticotropin-releasing hormone in irritable bowel syndrome and intestinal inflammation
Corticotropin-releasing hormone (CRH) is a major mediator of stress response in the brain-gut axis. Irritable bowel syndrome (IBS) is presumed to be a disorder of the brain-gut link associated with exaggerated response to stress.  The study by  Tohoku University Graduate School of Medicine, first showed that peripheral administration of CRH aggravated visceral sensorimotor function as well as adrenocorticotropic hormone (ACTH) response in IBS patients and administered alpha-helical CRH (alphahCRH), a non-selective CRH receptor antagonist among IBS patients. Electrical stimulation of the rectum induced significantly higher motility indices of the colon in IBS patients than in the controls. This response was significantly suppressed in IBS patients but not in the controls after administration of alphahCRH. Administration of alphahCRH induced a significant increase in the barostat bag volume of the controls but not in that of IBS patients. alphahCRH significantly reduced the ordinate scale of abdominal pain and anxiety evoked by electrical stimulation in IBS patients. Plasma ACTH and serum cortisol were generally not suppressed by alphahCRH. Last, administration of CRH1-receptor (CRH-R1) specific antagonist blocked colorectal distention-induced sensitization of the visceral perception in rats. Moreover, pretreatment with CRH-R1 antagonist blocked colorectal distention-induced anxiety, which was measured with elevated plus-maze, in rats. Evidence supporting the concept that peripheral CRH and CRH-R1 play important roles in brain-gut sensitization is increasing(5).

6. Effect of a corticotropin releasing hormone receptor antagonist on colonic sensory and motor function in patients with IBS.
Corticotropin releasing hormone (CRH) is a major mediator of the stress response in the brain-gut axis. Irritable bowel syndrome (IBS) is presumed to be a disorder of the brain-gut link associated with an exaggerated response to stress. In the study of ten normal healthy subjects and 10 IBS patients, diagnosed according to the Rome II criteria, the tone of the descending colon and intraluminal pressure of the sigmoid colon were measured at baseline, during rectal electrical stimulation (ES), and at recovery after administration of saline and visceral perception after colonic distension or rectal ES was evaluated as threshold values on an ordinate scale. The same measurements were repeated after administration of alphahCRH (10 micro g/kg), found that peripheral administration of alphahCRH improves gastrointestinal motility, visceral perception, and negative mood in response to gut stimulation, without affecting the hypothalamo-pituitary-adrenal axis in IBS patients(6).

7. Impact of corticotropin-releasing hormone on gastrointestinal motility and adrenocorticotropic hormone in normal controls and patients with IBS
Corticotropin-releasing hormone (CRH) plays a key role in modulating intestinal motility in stressed animals. In the study to evaluate the effect of CRH on intestinal motility in humans and to determine whether patients with irritable bowel syndrome (IBS) have an exaggerated response to CRH, showed that
CRH induced motility of the descending colon in both groups (p < 0.001) and induced greater motility indexes in IBS patients than in controls (p < 0.05). CRH produced duodenal phase III motor activity in 80% of the subjects and duodenal dysmotility in 40% of IBS patients. Abdominal symptoms evoked by CRH in IBS patients lasted significantly longer than those in controls (p < 0.05). CRH induced significant increases in plasma ACTH levels in both groups (p < 0.001) and produced significantly higher plasma ACTH levels in IBS patients than in controls (p < 0.001)(7).

8. Placental Corticotropin-Releasing Hormone Mediates the Association Between Prenatal Social Support and Postpartum Depression
In the study to test whether prenatal social support predicted depressive symptoms at 8 weeks postpartum in a multiethnic sample of 210 women and whether the stress hormone placental corticotropin-releasing hormone (pCRH), measured at 19, 29, and 37 weeks' gestation, mediated this relationship, found that prenatal family support predicted significantly fewer depressive symptoms postpartum and more gradual increases in pCRH from 29 to 37 weeks' gestation. Furthermore, steeper increases in pCRH during this same period predicted more depressive symptoms postpartum. Finally, these changes in pCRH in late pregnancy mediated the relationship between prenatal family support and postpartum depressive symptoms. These results suggest that social and biological risk factors for postpartum depressive symptoms are intertwined and move us closer to an integrated biopsychosocial understanding of postpartum depression(8).

Chinese Secrets To Fatty Liver And Obesity Reversal
Use The Revolutionary Findings To Achieve 
Optimal Health And Loose Weight

Super foods Library, Eat Yourself Healthy With The Best of the Best Nature Has to Offer

Back to Hormones

Back to Kyle J. Norton Home page   


No comments:

Post a comment