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Zhao F, Ma C, Zhao G, Wang G, Li X, Yang K. Rumen-Protected 5-Hydroxytryptophan Improves Sheep Melatonin Synthesis in the Pineal Gland and Intestinal Tract. Med Sci Monit 2019; 25:3605-3616. [PMID: 31091223 PMCID: PMC6534969 DOI: 10.12659/msm.915909] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Based on the extensive biological effects of melatonin (MLT), it is beneficial to increase the MLT content in the bodies of animals at a specific physiological stage. This study was conducted to investigate the effect of a diet supplemented with rumen-protected (RP) 5-hydroxytryptophan (5-HTP) on the pineal gland and intestinal tract MLT synthesis of sheep. MATERIAL AND METHODS Eighteen Kazakh sheep were assigned randomly to 3 diet groups: control group (CT, corn-soybean meal basal diet), CT+111 group (111 mg/kg BW RP 5-HTP), and CT+222 group (222 mg/kg BW RP 5-HTP). The gene expressions of aromatic amino acid decarboxylase (AADC), arylalkylamine N-acetyltransferase (AA-NAT), hydroxyindole-O-methyltransferase (HIOMT), monoamine oxidase A (MAOA), and the intermediates of MLT synthesis were observed from the pineal gland and intestinal tract by the reverse transcription (RT)-PCR method. The 5-HTP, 5-HT, N-acetylserotonin (NAS), MLT, and 5-hydroxyindole acetic acid (5-HIAA) contents in the pineal gland and intestinal tract were analyzed by ultra-high-performance liquid chromatography-tandem mass spectrometry. RESULTS The study showed that the pineal gland HIOMT expression (P<0.05), MLT (P<0.05) and 5-HIAA (P<0.05) levels in the 222 mg/kg group significantly increased compared to those in the CT and CT+111 mg/kg groups. In addition, the AADC (P<0.01) and AA-NAT (P<0.05) gene expression levels in the duodenum and jejunum were increased by the supplementation of RP 5-HTP. CONCLUSIONS Rumen-protected 5-hydroxytryptophan promoted melatonin synthesis in the pineal gland and intestinal tract during the natural light period.
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Affiliation(s)
- Fang Zhao
- College of Animal Science, Xinjiang Agricultural University, Urumqi, Xinjiang, China (mainland)
| | - Chen Ma
- College of Animal Science, Xinjiang Agricultural University, Urumqi, Xinjiang, China (mainland)
| | - Guodong Zhao
- College of Animal Science, Xinjiang Agricultural University, Urumqi, Xinjiang, China (mainland)
| | - Gen Wang
- College of Animal Science, Xinjiang Agricultural University, Urumqi, Xinjiang, China (mainland)
| | - Xiaobin Li
- College of Animal Science, Xinjiang Agricultural University, Urumqi, Xinjiang, China (mainland)
| | - Kailun Yang
- College of Animal Science, Xinjiang Agricultural University, Urumqi, Xinjiang, China (mainland)
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Esteban-Zubero E, López-Pingarrón L, Alatorre-Jiménez MA, Ochoa-Moneo P, Buisac-Ramón C, Rivas-Jiménez M, Castán-Ruiz S, Antoñanzas-Lombarte Á, Tan DX, García JJ, Reiter RJ. Melatonin's role as a co-adjuvant treatment in colonic diseases: A review. Life Sci 2016; 170:72-81. [PMID: 27919824 DOI: 10.1016/j.lfs.2016.11.031] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 11/17/2016] [Accepted: 11/30/2016] [Indexed: 02/07/2023]
Abstract
Melatonin is produced in the pineal gland as well as many other organs, including the enterochromaffin cells of the digestive mucosa. Melatonin is a powerful antioxidant that resists oxidative stress due to its capacity to directly scavenge reactive species, to modulate the antioxidant defense system by increasing the activities of antioxidant enzymes, and to stimulate the innate immune response through its direct and indirect actions. In addition, the dysregulation of the circadian system is observed to be related with alterations in colonic motility and cell disruptions due to the modifications of clock genes expression. In the gastrointestinal tract, the activities of melatonin are mediated by melatonin receptors (MT2), serotonin (5-HT), and cholecystokinin B (CCK2) receptors and via receptor-independent processes. The levels of melatonin in the gastrointestinal tract exceed by 10-100 times the blood concentrations. Also, there is an estimated 400 times more melatonin in the gut than in the pineal gland. Gut melatonin secretion is suggested to be influenced by the food intake. Low dose melatonin treatment accelerates intestinal transit time whereas high doses may decrease gut motility. Melatonin has been studied as a co-adjuvant treatment in several gastrointestinal diseases including irritable bowel syndrome (IBS), constipation-predominant IBS (IBS-C), diarrhea-predominant IBS (IBS-D), Crohn's disease, ulcerative colitis, and necrotizing enterocolitis. The purpose of this review is to provide information regarding the potential benefits of melatonin as a co-adjuvant treatment in gastrointestinal diseases, especially IBS, Crohn's disease, ulcerative colitis, and necrotizing enterocolitis.
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Affiliation(s)
- Eduardo Esteban-Zubero
- Department of Pharmacology and Physiology, University of Zaragoza. Calle Domingo Miral s/n, 50009 Zaragoza, Spain.
| | - Laura López-Pingarrón
- Department of Medicine, Psychiatry and Dermatology, University of Zaragoza. Calle Domingo Miral s/n, 50009 Zaragoza, Spain
| | - Moisés Alejandro Alatorre-Jiménez
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Purificación Ochoa-Moneo
- Department of Medicine, Psychiatry and Dermatology, University of Zaragoza. Calle Domingo Miral s/n, 50009 Zaragoza, Spain
| | - Celia Buisac-Ramón
- Primary Care Unit, Sector Zaragoza III, Avenida San Juan Bosco 5, 50009 Zaragoza, Spain
| | - Miguel Rivas-Jiménez
- Department of Medicine, Psychiatry and Dermatology, University of Zaragoza. Calle Domingo Miral s/n, 50009 Zaragoza, Spain
| | - Silvia Castán-Ruiz
- Primary Care Unit, Sector Zaragoza III, Avenida San Juan Bosco 5, 50009 Zaragoza, Spain
| | - Ángel Antoñanzas-Lombarte
- Department of Medicine, Psychiatry and Dermatology, University of Zaragoza. Calle Domingo Miral s/n, 50009 Zaragoza, Spain
| | - Dun-Xian Tan
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - José Joaquín García
- Department of Pharmacology and Physiology, University of Zaragoza. Calle Domingo Miral s/n, 50009 Zaragoza, Spain
| | - Russel J Reiter
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA.
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El-Dessouki AM, Galal MA, Awad AS, Zaki HF. Neuroprotective Effects of Simvastatin and Cilostazol in L-Methionine-Induced Vascular Dementia in Rats. Mol Neurobiol 2016; 54:5074-5084. [PMID: 27544235 DOI: 10.1007/s12035-016-0051-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 08/09/2016] [Indexed: 02/07/2023]
Abstract
Vascular dementia (VaD) is a degenerative cerebrovascular disorder that leads to progressive decline in cognitive abilities and memory. Several reports demonstrated that oxidative stress and endothelial dysfunction are principal pathogenic factors in VaD. The present study was constructed to determine the possible neuroprotective effects of simvastatin in comparison with cilostazol in VaD induced by L-methionine in rats. Male Wistar rats were divided into four groups. Group I (control group), group II received L-methionine (1.7 g/kg, p.o.) for 32 days. The remaining two groups received simvastatin (50 mg/kg, p.o.) and cilostazol (100 mg/kg, p.o.), respectively, for 32 days after induction of VaD by L-methionine. Subsequently, rats were tested for cognitive performance using Morris water maze test then sacrificed for biochemical and histopathological assays. L-methionine induced VaD reflected by alterations in rats' behavior as well as the estimated neurotransmitters, acetylcholinesterase activity as well as increased brain oxidative stress and inflammation parallel to histopathological changes in brain tissue. Treatment of rats with simvastatin ameliorated L-methionine-induced behavioral, neurochemical, and histological changes in a manner comparable to cilostazol. Simvastatin may be regarded as a potential therapeutic strategy for the treatment of VaD. To the best of our knowledge, this is the first study to reveal the neuroprotective effects of simvastatin or cilostazol in L-methionine-induced VaD. Graphical Abstract ᅟ.
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Affiliation(s)
- Ahmed M El-Dessouki
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ahram Canadian University, 6-October, 4th Industrial Area, Giza, 12566, Egypt.
| | - Mai A Galal
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
| | - Azza S Awad
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ahram Canadian University, 6-October, 4th Industrial Area, Giza, 12566, Egypt.
| | - Hala F Zaki
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
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Chang M, Li Y, Liu D, Zhang L, Zhang H, Tang H, Zhang H. Melatonin prevents secondary intra-abdominal hypertension in rats possibly through inhibition of the p38 MAPK pathway. Free Radic Biol Med 2016; 97:192-203. [PMID: 27264238 DOI: 10.1016/j.freeradbiomed.2016.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 05/31/2016] [Accepted: 06/01/2016] [Indexed: 01/30/2023]
Abstract
Exogenous administration of melatonin has been demonstrated to down-regulate inflammatory responses and attenuate organ damage in various models. However, the salutary effect of melatonin against secondary intra-abdominal hypertension (IAH) remains unclear. This study sought to test the influence of melatonin on secondary IAH in a pathophysiological rat model and the underlying mechanisms involved. Before resuscitation, male rats underwent a combination of induced portal hypertension, applying an abdominal restraint device, and hemorrhaging to mean arterial pressure (MAP) of 40mmHg for 2h. After blood reinfusion, the rats were treated with lactated Ringer solution (LR) (30mL/h), melatonin (50mg/kg) +LR, and SB-203580 (10μmol/kg)+LR. LR was continuously infused for 6h. MAP, the inferior vena cava pressure and urine output were monitored. Histopathological examination, immunofluorescence of tight junction proteins, and transmission electron microscopy were administered. Intestinal permeability, myeloperoxidase activity, malondialdehyde, glutathione peroxidase, and levels of TNF-a, IL-2, and IL-6, were assessed. The expression of extracellular signal-regulated kinase, p38, c-Jun NH2-terminal kinase, translocation of nuclear factor kappa B subunit, signal transducers and activators of transcription and tight junction proteins were detected by Western blot. We found that melatonin inhibited the inflammatory responses, decreased expression of p38 MAPK, attenuated intestinal injury, and prevented secondary IAH. Moreover, administration of SB203580 abolished the increase in p38 MAPK and also attenuated intestinal injury. These data indicate that melatonin exerts a protective effect in intestine in secondary IAH primarily by attenuating the inflammatory responses which are in part attributable to p38 MAPK inhibition.
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Affiliation(s)
- Mingtao Chang
- Trauma Center, State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Yang Li
- Trauma Center, State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Dong Liu
- Trauma Center, State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Lianyang Zhang
- Trauma Center, State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China.
| | - Hongguang Zhang
- Trauma Center, State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Hao Tang
- Trauma Center, State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Huayu Zhang
- Trauma Center, State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China
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Long AJ, Sampson E, McCarthy RW, Harris CM, Barnard M, Shi D, Conlon D, Caldwell R, Honor D, Wishart N, Hoemann M, Duggan L, Fritz D, Stedman C, O'Connor E, Mikaelian I, Schwartz A. Syk Inhibition Induces Platelet Dependent Peri-islet Hemorrhage in the Rat Pancreas. Toxicol Pathol 2016; 44:998-1012. [PMID: 27324990 DOI: 10.1177/0192623316654015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Spleen tyrosine kinase (Syk) is a nonreceptor tyrosine kinase that is an important signaling enzyme downstream of immunoreceptors containing an intracellular immunoreceptor tyrosine activating motif (ITAM). These receptors encompass a wide variety of biological functions involved in autoimmune disease pathogenesis. There has been considerable interest in the development of inhibitors of the Syk pathway for the treatment of rheumatoid arthritis and systemic lupus erythematosus. We report that Syk inhibition mechanistically caused peri-islet hemorrhages and fibrin deposition in the rat pancreas and that this finding is due to a homeostatic functional defect in platelets. In more limited studies, similar lesions could not be induced in mice, dogs, and cynomolgus monkeys at similar or higher plasma drug concentrations. Irradiation-induced thrombocytopenia caused a phenotypically similar peri-islet pancreas lesion and the formation of this lesion could be prevented by platelet transfusion. In addition, Syk inhibitor-induced lesions were prevented by the coadministration of prednisone. A relatively greater sensitivity of rat platelets to Syk inhibition was supported by functional analyses demonstrating rat-specific differences in response to convulxin, a glycoprotein VI agonist that signals through Syk. These data demonstrate that the Syk pathway is critical in platelet-endothelial cell homeostasis in the peri-islet pancreatic microvasculature in rats.
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Affiliation(s)
- Andrew J Long
- AbbVie Bioresearch Center, Worcester, Massachusetts, USA
| | - Erik Sampson
- AbbVie Bioresearch Center, Worcester, Massachusetts, USA
| | | | | | - Marc Barnard
- AbbVie Bioresearch Center, Worcester, Massachusetts, USA
| | - Dan Shi
- AbbVie Bioresearch Center, Worcester, Massachusetts, USA
| | - Donna Conlon
- AbbVie Bioresearch Center, Worcester, Massachusetts, USA
| | | | - David Honor
- AbbVie Bioresearch Center, Worcester, Massachusetts, USA
| | - Neil Wishart
- AbbVie Bioresearch Center, Worcester, Massachusetts, USA
| | | | - Lori Duggan
- AbbVie Bioresearch Center, Worcester, Massachusetts, USA
| | - Douglas Fritz
- AbbVie Bioresearch Center, Worcester, Massachusetts, USA
| | | | | | - Igor Mikaelian
- AbbVie Bioresearch Center, Worcester, Massachusetts, USA
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Effects of Melatonin on Stress-Induced Changes in the Liver of Rats with Different Resistance to Stress. Bull Exp Biol Med 2015. [PMID: 26201902 DOI: 10.1007/s10517-015-2950-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Effects of melatonin on changes in the liver structures were studied in stress-resistant and stress-sensitive rats exposed to chronic stress. It was found that the number of degenerative cells increased and intralobular sinusoidal capillary enlarged in the liver of animals of both groups. These parameters were significantly higher in stress-sensitive rats. Melatonin (1 mg/kg) reduced the severity of degenerative changes and stimulated the development of reparative processes in the liver tissue. The effects of the hormone was more pronounced in rats sensitive to stress and was noted after melatonin administration in a dose of 0.2 mg/kg.
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Bhattacharya P, Pandey AK, Paul S, Patnaik R. Melatonin renders neuroprotection by protein kinase C mediated aquaporin-4 inhibition in animal model of focal cerebral ischemia. Life Sci 2014; 100:97-109. [PMID: 24530291 DOI: 10.1016/j.lfs.2014.01.085] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 01/02/2014] [Accepted: 01/31/2014] [Indexed: 11/30/2022]
Abstract
AIM Aquaporin-4(AQP4) expression in the brain with relation to edema formation following focal cerebral ischemia was investigated. Studies have shown that brain edema is one of the significant factors in worsening stroke outcomes. While many mechanisms may aggravate brain injury, one such potential system may involve AQP4 up regulation in stroke patients that could result in increased edema formation. Post administration of melatonin following ischemic stroke reduces AQP4 mediated brain edema and confers neuroprotection. MATERIALS AND METHODS An in-silico approach was undertaken to confirm effective melatonin-AQP4 binding. Rats were treated with 5mg/kg, i.p. melatonin or placebo at 30 min prior, 60 min post and 120 min post 60 min of middle cerebral artery occlusion (MCAO) followed by 24h reperfusion. Rats were evaluated for battery of neurological and motor function tests just before sacrifice. Brains were harvested for infarct size estimation, water content measurement, biochemical analysis, apoptosis study and western blot experiments. KEY FINDINGS Melatonin at 60 min post ischemia rendered neuroprotection as evident by reduction in cerebral infarct volume, improvement in motor and neurological deficit and reduction in brain edema. Furthermore, ischemia induced surge in levels of nitrite and malondialdehyde (MDA) were also found to be significantly reduced in ischemic brain regions in treated animals. Melatonin potentiated intrinsic antioxidant status, inhibited acid mediated rise in intracellular calcium levels, decreased apoptotic cell death and also markedly inhibited protein kinase C (PKC) influenced AQP4 expression in the cerebral cortex and dorsal striatum. SIGNIFICANCE Melatonin confers neuroprotection by protein kinase C mediated AQP4 inhibition in ischemic stroke.
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Affiliation(s)
- Pallab Bhattacharya
- Department of Neurology, Leonard M. Miller School of Medicine, University of Miami, Miami, FL 33136, USA; School of Biomedical Engineering, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005, UP, India.
| | - Anand Kumar Pandey
- School of Biomedical Engineering, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005, UP, India
| | - Sudip Paul
- School of Biomedical Engineering, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005, UP, India; Department of Biomedical Engineering, North Eastern Hill University (NEHU), Shillong, 793022, Meghalaya, India
| | - Ranjana Patnaik
- School of Biomedical Engineering, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005, UP, India
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Prezotto LD, Lemley CO, Camacho LE, Doscher FE, Meyer AM, Caton JS, Awda BJ, Vonnahme KA, Swanson KC. Effects of nutrient restriction and melatonin supplementation on maternal and foetal hepatic and small intestinal energy utilization. J Anim Physiol Anim Nutr (Berl) 2013; 98:797-807. [DOI: 10.1111/jpn.12142] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- L. D. Prezotto
- Department of Animal Sciences; North Dakota State University; Fargo ND USA
| | - C. O. Lemley
- Department of Animal and Dairy Sciences; Mississippi State University; MS USA
| | - L. E. Camacho
- Department of Animal Sciences; North Dakota State University; Fargo ND USA
| | - F. E. Doscher
- Department of Animal Sciences; North Dakota State University; Fargo ND USA
| | - A. M. Meyer
- Division of Animal Science; University of Missouri; Columbia MO USA
| | - J. S. Caton
- Department of Animal Sciences; North Dakota State University; Fargo ND USA
| | - B. J. Awda
- College of Applied Biotechnology; Al-Nahrain University; Jadriah Baghdad Iraq
| | - K. A. Vonnahme
- Department of Animal Sciences; North Dakota State University; Fargo ND USA
| | - K. C. Swanson
- Department of Animal Sciences; North Dakota State University; Fargo ND USA
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Ursinus WW, Bolhuis JE, Zonderland JJ, Rodenburg TB, de Souza AS, Koopmanschap RE, Kemp B, Korte-Bouws GAH, Korte SM, van Reenen CG. Relations between peripheral and brain serotonin measures and behavioural responses in a novelty test in pigs. Physiol Behav 2013; 118:88-96. [PMID: 23685231 DOI: 10.1016/j.physbeh.2013.05.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 04/02/2013] [Accepted: 05/06/2013] [Indexed: 11/16/2022]
Abstract
Pigs differ in their behavioural responses towards environmental challenges. Individual variation in maladaptive responses such as tail biting, may partly originate from underlying biological characteristics related to (emotional) reactivity to challenges and serotonergic system functioning. Assessing relations between behavioural responses and brain and blood serotonin parameters may help in understanding susceptibility to the development of maladaptive responses. The objective of the current study was, therefore, to assess the relationship between the pigs' serotonergic parameters measured in both blood and brain, and the behaviour of pigs during a novelty test. Pigs (n=31) were subjected to a novelty test at 11weeks of age, consisting of 5-min novel environment exposure after which a novel object (a bucket) was introduced for 5min. Whole blood serotonin, platelet serotonin level, and platelet serotonin uptake were determined at 13weeks of age. Levels of serotonin, its metabolite and serotonin turnover were determined at 19weeks of age in the frontal cortex, hypothalamus and hippocampus. The behaviour of the pigs was different during exposure to a novel object compared to the novel environment only, with more fear-related behaviours exhibited during novel object exposure. Platelet serotonin level and brain serotonergic parameters in the hippocampus were interrelated. Notably, the time spent exploring the test arena was significantly correlated with both platelet serotonin level and right hippocampal serotonin activity (turnover and concentration). In conclusion, the existence of an underlying biological trait - possibly fearfulness - may be involved in the pig's behavioural responses toward environmental challenges, and this is also reflected in serotonergic parameters.
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Affiliation(s)
- Winanda W Ursinus
- Wageningen University, Department of Animal Sciences, Adaptation Physiology Group, P.O. Box 338, 6700 AH, Wageningen, The Netherlands.
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Abstract
BACKGROUND Anxiety and depression, conditions frequently associated with childhood chronic abdominal pain (AP), are characterized by seasonal exacerbations. A seasonal pattern characterized by a higher frequency of consultations for AP during winter has been suspected but has never, to our knowledge, been demonstrated. We hypothesize the presence of a seasonal variation in AP consultations with a winter predominance. AIMS To determine the seasonal distribution of AP consultations among centers across time and geographic latitude. PATIENTS AND METHODS This was a retrospective cohort study. The number of outpatient consultations from primary care clinics and every pediatric specialty clinic that resulted in a diagnosis of AP and the total number of outpatient consultations (2001-2004) from 6 tertiary care institutions (Chicago, Pittsburgh, Wilmington, Pensacola, Orlando, Jacksonville) was determined. Rates of consultations were compared across time and between cities. Four time periods of interest, with 2- and 3-month definitions, were arbitrarily selected. Seasonal rates across time were compared separately for each of the 2-month (January-February vs June-July) and 3-month periods (January-March vs June-August). Logistic regression models for each city were used to determine variations in the rate of outpatient AP cases by season or by year. RESULTS A total of 3,929,522 outpatient consultations and 73,591 AP consultations were analyzed. The rates of AP consultations were consistently higher in the winter months at all of the sites. The results differed between sites at northern and southern latitudes. CONCLUSIONS There seems to be a seasonal variation in consultation patterns for AP at the tertiary care level. A possible role of daylight hours, climate, latitude, and stress is proposed.
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Mathes AM, Kubulus D, Pradarutti S, Bentley A, Weiler J, Wolf B, Ziegeler S, Bauer I, Rensing H. Melatonin pretreatment improves liver function and hepatic perfusion after hemorrhagic shock. Shock 2008; 29:112-8. [PMID: 17666950 DOI: 10.1097/shk.0b013e3180644ca3] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Exogenous administration of pineal hormone melatonin (MEL) has been demonstrated to attenuate organ damage in models of I/R and inflammation by antioxidative effects. However, specific organ-protective effects of MEL with respect to hemorrhagic shock have not been investigated yet. In the present study, we evaluated the role of MEL pretreatment for hepatic perfusion, redox state, and function after hemorrhage and resuscitation, with emphasis on MEL receptor activation. In a model of hemorrhagic shock (MAP 35 +/- 5 mmHg for 90 min) and reperfusion (2 h), we measured nicotinamide adenine dinucleotide phosphate (reduced form; NADPH) autofluorescence, hepatic microcirculation, and hepatocellular injury by intravital microscopy, as well as plasma disappearance rate of indocyanine green (PDRICG) as a sensitive maker of liver function in rat. Pretreatment with 10 mg kg(-1) MEL (i.v.) 15 min before induction of hemorrhage resulted in a significantly improved PDR(ICG) compared with controls (MEL/shock, 15.02% min(-1) +/- 2.9 SD vs. vehicle/shock, 6.18 +/- 4.6 SD; P = 0.001). Intravital microscopy after reperfusion revealed an improved hepatic perfusion index, redox state, and reduced hepatocellular injury in pretreated animals compared with the vehicle group. Melatonin receptor antagonist luzindole (LZN; 2.5 mg kg(-1)) almost completely abolished the protective effects of MEL pretreatment with respect to liver function (MEL + LZN/shock PDR(ICG), 7.31% min(-1) +/- 3.4 SD). Beneficial effects regarding hepatic perfusion, redox state, and cellular injury were not influenced by LZN, indicating that they may depend on antioxidative effects of MEL. However, liver function after hemorrhage is effectively maintained by MEL pretreatment via receptor-dependent pathways.
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Affiliation(s)
- Alexander M Mathes
- Department of Anesthesiology, Critical Care Medicine and Pain Management, Saarland University Hospital; Kirrberger Strasse; D-66421 Homburg (Saar), Germany
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Melatonin receptors mediate improvements of liver function but not of hepatic perfusion and integrity after hemorrhagic shock in rats. Crit Care Med 2008; 36:24-9. [PMID: 18090374 DOI: 10.1097/01.ccm.0000292088.33318.f0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Melatonin has been demonstrated to attenuate organ damage in models of ischemia and reperfusion. Melatonin treatment before hemorrhagic shock has been shown to improve liver function and hepatic perfusion. Proposed mechanisms of the pineal hormone involve direct inactivation of reactive oxygen species and induction of antioxidative enzymes. However, recent evidence suggests a strong influence of melatonin receptor activation for these effects. Specific protection of organ function by melatonin after hemorrhage has not been investigated yet. In this study, we evaluated whether melatonin therapy after hemorrhagic shock improves liver function and hepatic perfusion, with emphasis on melatonin receptor activation. DESIGN Prospective, randomized, controlled study. SETTING University research laboratory. SUBJECTS Male Sprague-Dawley rats, 200-300 g (n = 10 per group). INTERVENTIONS Animals underwent hemorrhagic shock (mean arterial pressure, 35 +/- 5 mm Hg for 90 mins) and were resuscitated with shed blood and Ringer's solution. At the end of shock, animals were treated with either melatonin (10 mg/kg, intravenously), melatonin receptor antagonist luzindole (2.5 mg/kg, intravenously) plus melatonin (10 mg/kg, intravenously), luzindole alone (2.5 mg/kg, intravenously), or vehicle. MEASUREMENTS AND MAIN RESULTS After 2 hrs of reperfusion, either liver function was assessed by plasma disappearance rate of indocyanine green or intravital microscopy of the liver was performed for evaluation of hepatic perfusion, hepatocellular redox state, and hepatic integrity. Compared with vehicle controls, melatonin therapy after hemorrhagic shock significantly improved plasma disappearance rate of indocyanine green, hepatic redox state, hepatocellular injury, and hepatic perfusion index. Coadministration of luzindole completely abolished the protective effect with respect to liver function only, and improvements regarding hepatic redox state, perfusion, and integrity were comparable with melatonin treatment alone. CONCLUSIONS Melatonin therapy after hemorrhagic shock improves liver function, hepatic perfusion, redox state, and hepatic integrity. With respect to liver function, beneficial effects of the pineal hormone seem to be dependent on melatonin receptor activation.
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