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Rodríguez-González D, Guerrero Legarreta I, Cruz-Monterrosa RG, Napolitano F, Titto CG, Abd El-Aziz AH, Hernández-Avalos I, Casas-Alvarado A, Domínguez-Oliva A, Mota-Rojas D. Assessment of thermal changes in water buffalo mobilized from the paddock and transported by short journeys. Front Vet Sci 2023; 10:1184577. [PMID: 37252398 PMCID: PMC10217363 DOI: 10.3389/fvets.2023.1184577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 04/24/2023] [Indexed: 05/31/2023] Open
Abstract
Evaluating the welfare of buffaloes during transport is key to obtaining and commercializing high-quality meat products; however, effective assessments require recognizing several stressors that activate physiological mechanisms that can have repercussions on the health and productive performance of species. The aim of this study was to evaluate the surface temperatures of different body and head regions in this species during events prior, and posterior, to transport for short periods; that is, from paddock to loading. The second goal was to determine the level of correlation between thermal windows. This study used infrared thermography (IRT) to evaluate the surface temperature of 624 water buffaloes (Buffalypso breed) during 12 short trips (average duration = 2 h ± 20 min) by focusing on 11 regions of the body (Regio corporis), in the head regions (Regiones capitis) the face regions (Regiones faciei), Orbital region (Regio orbitalis) with special attention to structures such as the lacrimal caruncle, periocular area and lower eyelid (Regio palpebralis inferior); nasal region (Regio nasalis) with special attention to nostril thermal window; and regions of the skull (Regiones cranii) such as auricular region (Regio auricularis) with special attention to auditory canal and frontal-parietal region (Regio frontalis-parietalis) and trunk region (Truncus regionis) such as thoracic and abdominal regions, regions of the vertebral column (Columna vertebralis) with the thoracic vertebral region (Regio vertebralis thoracis) and lumbar region (Regio lumbalis); and regions of the pelvis limb (Regiones membri pelvini). Recordings were made during seven phases: paddock (P1), herding (P2), corral (P3), chute handling (P4), shipping (P5), pre- (P6), and post-transport (P7). A total of 48,048 readings were obtained from 11 thermal windows. The results showed that the surface temperatures of the windows increased by as much as 5°C during P2, P3, P5, P6, and P7 compared to P1 and P4 (p < 0.0001). Differences of at least 1°C were also observed between thermal windows in the craniofacial, lateral corporal, and peripheral zones (p < 0.0001). Finally, a strong positive correlation (r = 0.9, p < 0.0001) was found between the thermal windows. These findings lead to the conclusion that the surface temperature of the craniofacial and corporal regions of buffaloes transported for short periods varied in relation to the phase of mobilization (from paddock to post-transport), likely as a response to stressful factors, since herding and loading increased the thermal values in each window. The second conclusion is that there are strong positive correlations between central and peripheral thermal windows.
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Affiliation(s)
- Daniela Rodríguez-González
- Master’s Program in Agricultural and Livestock Sciences [Maestría en Ciencias Agropecuarias], Universidad Autónoma Metropolitana (UAM), Xochimilco Campus, Mexico City, Mexico
| | - Isabel Guerrero Legarreta
- Department of Biotechnology: Food Science, Universidad Autónoma Metropolitana, Iztapalapa Campus (UAM-I), Mexico City, Mexico
| | - Rosy G. Cruz-Monterrosa
- Department of Food Science, Universidad Autónoma Metropolitana (UAM-L), Campus Lerma, Lerma City, Mexico
| | - Fabio Napolitano
- Scuola di Scienze Agrarie, Forestali, Alimentari ed Ambientali, Università degli Studi della Basilicata, Potenza, Italy
| | - Cristiane Gonçalves Titto
- Laboratório de Biometeorologia e Etologia, Faculdade de Zootecnia e Engenharia de Alimentos, FZEA-USP, Universidade de São Paulo, Pirassununga, Brazil
| | - Ayman H. Abd El-Aziz
- Animal Husbandry and Animal Wealth Development Department, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt
| | - Ismael Hernández-Avalos
- Department of Biological Science, FESC, Universidad Nacional Autónoma de México (UNAM), Cuautitlán Izcalli, Mexico
| | - Alejandro Casas-Alvarado
- Neurophysiology, Behavior and Animal Welfare Assessment, DPAA, Universidad Autónoma Metropolitana (UAM), Xochimilco Campus, Mexico City, Mexico
| | - Adriana Domínguez-Oliva
- Neurophysiology, Behavior and Animal Welfare Assessment, DPAA, Universidad Autónoma Metropolitana (UAM), Xochimilco Campus, Mexico City, Mexico
| | - Daniel Mota-Rojas
- Neurophysiology, Behavior and Animal Welfare Assessment, DPAA, Universidad Autónoma Metropolitana (UAM), Xochimilco Campus, Mexico City, Mexico
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Al-Hassan S, Attia H, Alomar H, Arafa M, Ali RA. The inhibitory mechanisms of losartan and vitamin D on amiodarone-induced lung inflammation in rats: Role of mitogen-activated protein kinases/activator protein-1. J Biochem Mol Toxicol 2021; 35:e22923. [PMID: 34590760 DOI: 10.1002/jbt.22923] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 08/22/2021] [Accepted: 09/20/2021] [Indexed: 11/09/2022]
Abstract
Amiodarone (AMD), an antiarrhythmic drug, is used cautiously due to its lung toxicity that is characterized by alveolar inflammation followed by fatal fibrosis. AMD induces lung inflammation via increasing the alveolar macrophages and disturbing the balance of T-helper-1 (Th1) and Th2 cells cytokines. In this study, the role of the mitogen-activated protein kinases (MAPKs)/activator protein-1 (AP-1) pathway in AMD-induced lung inflammation was evaluated. Also, the anti-inflammatory and antifibrotic effects of losartan and/or vitamin D were investigated following 7, 14, and 28 days of AMD administration. AMD resulted in lung injury, inflammatory infiltration, and increased pulmonary levels of inflammatory cytokines starting from Week 1 of exposure. A significant increase in serum levels of interleukin-4 along with a significant reduction of interferon-gamma, in addition to strong expression of CD68, were reported after 14 and 28 days of AMD administration reflecting Th1/Th2 cytokines imbalance and the accumulation of alveolar macrophages, respectively. The phosphorylation of MAPKs (ERK1/2, JNK, p38) and AP-1 was significantly enhanced starting from Week 1 of exposure. Marked expression of transforming growth factor beta-1 and massive deposition of collagen were detected after 28 days reflecting late fibrosis. All these abnormalities were significantly mitigated by vitamin D and its combination with losartan. Losartan alone has less prominent anti-inflammatory effects particularly after 28 days; however, it efficiently prevented late fibrosis. This study concludes that MAPKs/AP-1 pathway is involved in AMD-induced lung inflammation and that vitamin D and/or losartan could be used as a prophylactic agent to prevent AMD-induced lung toxicity.
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Affiliation(s)
- Sara Al-Hassan
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.,Department of Pricing and Pharmacoeconomics, Drug Sector, Saudi Food and Drug Authority, Riyadh, Saudi Arabia
| | - Hala Attia
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.,Department of Biochemistry, College of Pharmacy, Mansours University, Mansoura, Egypt
| | - Hatun Alomar
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Maha Arafa
- Department of Pathology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Rehab A Ali
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
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Robertson JK, Mastromonaco G, Burness G. Evidence that stress-induced changes in surface temperature serve a thermoregulatory function. J Exp Biol 2020; 223:jeb213421. [PMID: 31974220 DOI: 10.1242/jeb.213421] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 01/20/2020] [Indexed: 08/26/2023]
Abstract
The fact that body temperature can rise or fall following exposure to stressors has been known for nearly two millennia; however, the functional value of this phenomenon remains poorly understood. We tested two competing hypotheses to explain stress-induced changes in temperature, with respect to surface tissues. Under the first hypothesis, changes in surface temperature are a consequence of vasoconstriction that occur to attenuate blood loss in the event of injury and serve no functional purpose per se; defined as the 'haemoprotective hypothesis'. Under the second hypothesis, changes in surface temperature reduce thermoregulatory burdens experienced during activation of a stress response, and thus hold a direct functional value: the 'thermoprotective hypothesis'. To understand whether stress-induced changes in surface temperature have functional consequences, we tested predictions of these two hypotheses by exposing black-capped chickadees (n=20) to rotating stressors across an ecologically relevant ambient temperature gradient, while non-invasively monitoring surface temperature (eye region temperature) using infrared thermography. Our results show that individuals exposed to rotating stressors reduce surface temperature and dry heat loss at low ambient temperature and increase surface temperature and dry heat loss at high ambient temperature, when compared with controls. These results support the thermoprotective hypothesis and suggest that changes in surface temperature following stress exposure have functional consequences and are consistent with an adaptation. Such findings emphasize the importance of the thermal environment in shaping physiological responses to stressors in vertebrates, and in doing so, raise questions about their suitability within the context of a changing climate.
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Affiliation(s)
- Joshua K Robertson
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada, K9L 0G2
- Department of Reproductive Physiology, The Toronto Zoo, Scarborough, Ontario, Canada, M1B 5K7
| | - Gabriela Mastromonaco
- Department of Reproductive Physiology, The Toronto Zoo, Scarborough, Ontario, Canada, M1B 5K7
| | - Gary Burness
- Department of Biology, Trent University, Peterborough, Ontario, Canada, K9L 0G2
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Chaffin ATB, Fang Y, Larson KR, Mul JD, Ryan KK. Sex-dependent effects of MC4R genotype on HPA axis tone: implications for stress-associated cardiometabolic disease. Stress 2019; 22:571-580. [PMID: 31184537 PMCID: PMC6690797 DOI: 10.1080/10253890.2019.1610742] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 04/18/2019] [Indexed: 12/15/2022] Open
Abstract
The melanocortin-4 receptor (MC4R) facilitates hypothalamic-pituitary-adrenocortical (HPA) axis responses to acute stress in male rodents and is a well known to regulator of energy balance. Mutations in the MC4R is the most common monogenic cause of obesity in humans and has been associated with sex-specific effects, but whether stress regulation by the MC4R is sex-dependent, and whether the MC4R facilitates HPA responses to chronic stress, is unknown. We hypothesized that MC4R-signaling contributes to HPA axis dysregulation and metabolic pathophysiology following chronic stress exposure. We measured changes in energy balance, HPA axis tone, and vascular remodeling during chronic variable stress (CVS) in male and female rats with MC4R loss-of-function. Rats were placed into three groups (n = 9-18/genotype/sex) and half of each group was subjected to CVS for 30 days or were non-stressed littermate controls. All rats underwent an acute restraint stress challenge on Day 30. Rats were euthanized on Day 31, adrenals collected for weight, and descending aortas fixed for morphological indices of vascular pathophysiology. We observed a marked interaction between Mc4r genotype and sex for basal HPA axis tone and acute stress responsivity. MC4R loss-of-function blunted both endpoints in males but exaggerated them in females. Contrary to our hypothesis, Mc4r genotype had no effect on either HPA axis responses or metabolic responses to chronic stress. Heightened stress reactivity of females with MC4R mutations suggests a possible mechanism for the sex-dependent effects associated with this mutation in humans and highlights how stress may differentially regulate metabolism in males and females. Lay summary The hypothalamic melanocortin system is an important regulator of energy balance and stress responses. Here, we report a sex-difference in the stress reactivity of rats with a mutation in this system. Our findings highlight how stress may regulate metabolism differently in males and females and may provide insight into sex-differences associated with this mutation in humans.
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Affiliation(s)
- Aki T-B Chaffin
- a Department of Neurobiology, Physiology and Behavior, University of California , Davis , CA , USA
| | - Yanbin Fang
- a Department of Neurobiology, Physiology and Behavior, University of California , Davis , CA , USA
| | - Karlton R Larson
- a Department of Neurobiology, Physiology and Behavior, University of California , Davis , CA , USA
| | - Joram D Mul
- b Amsterdam UMC, University of Amsterdam , The Netherlands
- c Metabolism and Reward Group, Netherlands Institute for Neuroscience , Amsterdam , The Netherlands
| | - Karen K Ryan
- a Department of Neurobiology, Physiology and Behavior, University of California , Davis , CA , USA
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Boyle NB, Dye L, Arkbåge K, Thorell L, Frederiksen P, Croden F, Lawton C. Effects of milk-based phospholipids on cognitive performance and subjective responses to psychosocial stress: A randomized, double-blind, placebo-controlled trial in high-perfectionist men. Nutrition 2018; 57:183-193. [PMID: 30172995 DOI: 10.1016/j.nut.2018.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 04/23/2018] [Accepted: 05/04/2018] [Indexed: 10/16/2022]
Abstract
OBJECTIVES The aim of this study was to examine the stress-buffering potential of phospholipid (PL) intake on cognitive performance and neuroendocrine and psychological responses under conditions of psychosocial stress in a high-stress vulnerable (perfectionist) sample. METHODS Fifty-four high-perfectionist men consumed a 6-wk daily intake of a bovine milk-derived PL (2.7 g/d) or placebo drink in a randomized, double-blind, placebo-controlled, parallel groups design. Working memory, executive control function, and acute physiological/subjective responses to an acute psychosocial stressor were examined before and after the 6-wk PL or placebo intake. RESULTS PL intake improved post-stress reaction time performance on an attention-switching task (P = 0.01). No significant attenuation of the salivary cortisol stress response was shown. PL intake significantly increased mid-stress induction energetic arousal (P = 0.03). A non-significant reduction in anticipatory subjective stress was reported after PL intake (P = 0.06). Systolic and diastolic blood pressures (P<0.04 and P = 0.01, respectively) were significantly augmented in the PL condition. CONCLUSIONS Dietary intake of bovine milk PLs conferred cognitive performance benefit under conditions of psychosocial stress but failed to moderate cortisol response. Moderation of subjective response to stress exposure may have underpinned this performance protection.
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Affiliation(s)
- Neil B Boyle
- School of Psychology, The University of Leeds, Leeds, United Kingdom.
| | - Louise Dye
- School of Psychology, The University of Leeds, Leeds, United Kingdom
| | - Karin Arkbåge
- Arla Strategic Innovation Centre, Arla Foods, Stockholm, Sweden
| | - Lars Thorell
- Arla Strategic Innovation Centre, Arla Foods, Stockholm, Sweden
| | | | - Fiona Croden
- School of Psychology, The University of Leeds, Leeds, United Kingdom
| | - Clare Lawton
- School of Psychology, The University of Leeds, Leeds, United Kingdom
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Turjeman K, Barenholz Y. Liposomal nano-drugs based on amphipathic weak acid steroid prodrugs for treatment of inflammatory diseases. J Drug Target 2016; 24:805-820. [PMID: 27750439 DOI: 10.1080/1061186x.2016.1236262] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Steroids are the most efficacious anti-inflammatory agents. However, their toxicities and side-effects compromise their clinical application. Various strategies and major efforts were dedicated for formulating viable liposomal glucocorticosteroids (GCs), so far none of these were approved. OBJECTIVES To evaluate these approaches for formulating GC-delivery systems, especially liposomes, and with focus on the Barenholz Lab experience. METHODS We developed PEGylated nano-liposomes (NSSL) remotely loaded with water-soluble amphipathic weak acid GC-prodrugs. Their remote loading results in high, efficient and stable loading to the level that enables human clinical use. We characterized them for their physical chemistry and stability. We demonstrated their therapeutic efficacy in relevant animal models and studied their pharmacokinetics (PK), biodistribution (BD) and pharmacodynamics advantages over the free pro-drugs. RESULTS Our steroidal nano-drugs demonstrate much superior PK, BD, tolerability and therapeutic efficacies compared to the free pro-drugs and to most drugs currently used to treat these diseases. These nano-drugs act as robust immune-suppressors, affecting cytokines secretion and diminishing hemorrhage and edema. CONCLUSIONS The combination of improved physical-chemistry, PK, BD, tolerability and therapeutic efficacy of these steroidal nano-drugs over the pro-drugs "as-is" support their further clinical development as potential therapeutic agents for treating inflammatory diseases.
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Affiliation(s)
- Keren Turjeman
- a Department of Biochemistry and Molecular Biology, Laboratory of Membrane and Liposome Research , Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School , Jerusalem , Israel
| | - Yechezkel Barenholz
- a Department of Biochemistry and Molecular Biology, Laboratory of Membrane and Liposome Research , Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School , Jerusalem , Israel
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Sakakibara H, Torii Yasuda M, Shimoi K. Effects of environmental and social stressors on biological rhythms. THE JOURNAL OF PHYSICAL FITNESS AND SPORTS MEDICINE 2016. [DOI: 10.7600/jpfsm.5.143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
| | | | - Kayoko Shimoi
- School of Food and Nutritional Sciences, University of Shizuoka
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Abstract
Severe pain has profound physiologic effects on the endocrine system. Serum hormone abnormalities may result and these serve as biomarkers for the presence of severe pain and the need to replace hormones to achieve pain control. Initially severe pain causes a hyperarousal of the hypothalamic-pituitary-adrenal system which results in elevated serum hormone levels such as adrenocorticotropin, cortisol, and pregnenolone. If the severe pain does not abate, however, the system cannot maintain its normal hormone production and serum levels of some hormones may drop below normal range. Some hormones are so critical to pain control that a deficiency may enhance pain and retard healing.
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Svendsen PF, Madsbad S, Nilas L, Paulsen SK, Pedersen SB. Expression of 11beta-hydroxysteroid dehydrogenase 1 and 2 in subcutaneous adipose tissue of lean and obese women with and without polycystic ovary syndrome. Int J Obes (Lond) 2009; 33:1249-56. [PMID: 19704410 DOI: 10.1038/ijo.2009.165] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVE To investigate the expression of 11beta-hydroxysteroid dehydrogenase (11beta-HSD) type 1 and 2 and hexose-6-phosphate dehydrogenase (H6PDH) mRNA in subcutaneous abdominal tissue from lean and obese women with and without polycystic ovary syndrome (PCOS), and to investigate the association between these enzymes and different measures of insulin sensitivity. DESIGN Cross-sectional study. SUBJECTS A total of 60 women, 36 women with PCOS, 17 lean (lean PCOS, LP) and 19 obese (obese PCOS, OP) and 24 age- and weight-matched control women, 8 lean (lean controls, LC) and 16 obese (obese controls, OC). Subcutaneous adipose tissue was collected from the abdomen. Peripheral insulin sensitivity was assessed by the euglycemic hyperinsulinemic clamp and determined as glucose disposal rate and insulin sensitivity index. Whole-body insulin sensitivity was calculated using homeostasis model assessment insulin resistance index. Body composition was evaluated by dual X-ray absorptiometry. Adipose mRNA expression of leptin and adiponectin were determined by real-time PCR. RESULTS Polycystic ovary syndrome (P<0.05) and obesity (P<0.05) were independently associated with increased expression of 11beta-HSD1 mRNA. The subgroups LP and OC had increased 11beta-HSD1 and 11beta-HSD2 mRNA expression compared with LC (P<0.05, P<0.05). There were no effects of PCOS or obesity on11beta-HSD2 or H6PDH mRNA expression. Decreased peripheral insulin sensitivity (P<0.001) and increased upper body fat distribution (P<0.01) were associated with increased expression of 11beta-HSD1, but neither 11beta-HSD2 nor H6PDH. CONCLUSION Polycystic ovary syndrome and obesity are independently associated with increased expression of 11beta-HSD1. This may lead to increased conversion of cortisone to cortisol in the peripheral adipose tissue and subsequently increased glucocorticoid activity. Decreased peripheral insulin sensitivity and central obesity was associated with increased expression of 11beta-HSD1.
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Affiliation(s)
- P F Svendsen
- Department of Obstetrics and Gynaecology, Copenhagen University Hospital, Hvidovre, Denmark.
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Abstract
Depression frequently is comorbid with a variety of medical illnesses; individuals who have such comorbidities may have increased morbidity and lower functional status. Usual antidepressant treatments can be effective in depressed patients who have comorbid medical illness. These patients, however, experience lower rates of recovery and remission of depressive symptoms and higher rates of relapse during follow-up than seen in patients who have MDD with no medical comorbidity. Comorbid medical illness therefore is a marker of treatment resistance in MDD. Collaborative treatments combining antidepressants, psychotherapy, education, and case management may be effective and could overcome the risk of treatment resistance. Two clinical strategies seem warranted in light of the studies presented here: (1) an increased index of suspicion for depression in medically ill patients, and (2) more intensive antidepressant treatment in depressed patients who have medical comorbidity.
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Affiliation(s)
- Dan V Iosifescu
- Depression Clinical and Research Program, Massachusetts General Hospital, 50 Staniford Street, Suite 401, Boston, MA 02114, USA.
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Wen PY, Schiff D, Kesari S, Drappatz J, Gigas DC, Doherty L. Medical management of patients with brain tumors. J Neurooncol 2006; 80:313-32. [PMID: 16807780 DOI: 10.1007/s11060-006-9193-2] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2006] [Accepted: 05/03/2006] [Indexed: 10/24/2022]
Abstract
The most common medical problems in brain tumor patients include the management of seizures, peritumoral edema, medication side effects, venous thromboembolism (VTE), fatigue and cognitive dysfunction. Despite their importance, there are relatively few studies specifically addressing these issues. There is increasing evidence that brain tumor patients who have not had a seizure do not benefit from prophylactic antiepileptic medications. Patients on corticosteroids are at greater risk of Pneumocystis jerovecii pneumonia and may benefit from prophylactic therapy. There is also growing evidence suggesting that anticoagulation may be more effective than inferior vena cava IVC) filtration devices for treating VTE in brain tumor patients and the risk of hemorrhage with anticoagulation is relatively small. Low-molecular weight heparin may be more effective than coumadin. Medications such as modafinil and methylphenidate have assumed an increasing role in the treatment of fatigue, while donepezil and memantine may be helpful with memory loss.
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Affiliation(s)
- Patrick Y Wen
- Division of Neuro-Oncology, Department of Neurology, Brigham and Women's Hospital and Center for Neuro-Oncology, Dana-Farber Brigham and Women's Cancer Center, SW430D, 44 Binney Street, Boston, MA 02115, USA.
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Mai K, Kullmann V, Bobbert T, Maser-Gluth C, Möhlig M, Bähr V, Pfeiffer AFH, Spranger J, Diederich S. In vivo activity of 11beta-hydroxysteroid dehydrogenase type 1 and free fatty acid-induced insulin resistance. Clin Endocrinol (Oxf) 2005; 63:442-9. [PMID: 16181237 DOI: 10.1111/j.1365-2265.2005.02362.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Free fatty acids (FFAs) induce hepatic insulin resistance and enhance hepatic gluconeogenesis. Glucocorticoids (GCs) also stimulate hepatic gluconeogenesis. The aim of this study was to investigate whether the FFA-induced hepatic insulin resistance is mediated by increased activity of hepatic 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1), accompanied by elevated hepatic cortisol levels. METHODS Following a 10-h overnight fast, six healthy male volunteers were investigated. A euglycaemic hyperinsulinaemic clamp was performed during lipid or saline infusion. To assess hepatic 11beta-HSD1 activity, plasma cortisol levels were measured after oral administration of cortisone acetate during lipid or saline infusion. In addition, 11beta-HSD activities were determined in vivo by calculating the urinary ratios of GC metabolites. RESULTS Lipid infusion increased FFAs (5.41 +/- 1.00 vs. 0.48 +/- 0.20 mmol/l; P < 0.005) and significantly increased insulin resistance [glucose infusion rate (GIR) 6.02 +/- 2.60 vs. 4.08 +/- 2.15 mg/kg/min; P < 0.005]. After lipid and saline infusions no changes in 11beta-HSD1 activity were found, neither by changes in cortisone acetate to cortisol conversion nor by differences in urinary free cortisol (UFF) or cortisone (UFE), 5beta-tetrahydrocortisol (THF), 5alpha-THF, cortisone (THE), UFF/UFE and (5alpha-THF + THF)/THE ratios. CONCLUSIONS We found no change in hepatic and whole-body 11beta-HSD1 activity during acute FFA-induced insulin resistance. Further studies are necessary to clarify whether 11beta-HSD1 in muscle and adipose tissue is influenced by FFAs and whether 11beta-HSD1 is involved in other conditions of insulin resistance.
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Affiliation(s)
- K Mai
- Department of Endocrinology, Diabetes and Nutrition, Charite Humanmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
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Iosifescu DV, Bankier B, Fava M. Impact of medical comorbid disease on antidepressant treatment of major depressive disorder. Curr Psychiatry Rep 2004; 6:193-201. [PMID: 15142472 DOI: 10.1007/s11920-004-0064-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A major factor in evaluating and treating depression is the presence of comorbid medical problems. In this paper, the authors will first evaluate studies showing that medical illness is a risk factor for depression. The authors will review a series of randomized, controlled studies of antidepressant treatment in subjects with major depressive disorder (MDD) and comorbid medical illnesses (myocardial infarction, stroke, diabetes, cancer, and rheumatoid arthritis). Most of these studies report an advantage for an active antidepressant over placebo in improvement of depressive symptoms. The authors also will review a series of studies in which the outcome of antidepressant treatment is compared between subjects with MDD with and without comorbid medical illness. In these studies, subjects with medical illness tend to have lower improvement of depressive symptoms and higher rates of depressive relapse with antidepressant treatment compared with MDD subjects with no medical comorbidity. In addition, the authors will review hypotheses on the mechanism of the interaction between medical illness and clinical response in MDD. The paper will conclude that medical comorbidity is a predictor of treatment resistance in MDD.
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Affiliation(s)
- Dan V Iosifescu
- Massachusetts General Hospital, 50 Staniford Street, Suite 401, Boston, MA 02114, USA.
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Abstract
Elevated cortisol in a subset of depressed patients is an enduring and well-replicated finding. Much interest has focused on the possible effects of depression on the hippocampus; however, an emerging body of evidence suggests an association between depression and non-central nervous system illnesses. In this review, data on the effects of depression on the brain and other organ systems sensitive to elevated cortisol are discussed. From searches of the MEDLINE, PSYCHINFO, and Current Contents databases, and other sources, articles were found specifically related to depression and physical changes or medical conditions associated with corticosteroid excess in patients with Cushing's disease, including cognitive impairment, hippocampal atrophy, increased waist-to-hip ratio, bone loss, hypertension, diabetes, peptic ulcers, and hyperlipidemia. Data are strongest for a relationship between elevated cortisol and depression, hippocampal atrophy, cognitive impairment, abdominal obesity, and loss of bone density. Some evidence suggests an association between depression and hypertension, peptic ulcers, and diabetes. Depression does not appear to be associated with hyperlipidemia. The data provide some support for similar health effects in depressed patients and patients with Cushing's disease or the metabolic syndrome; however, additional studies are needed relating systemic effects of depression to cortisol. Limitations of the current literature, treatment implications, and possible directions for future research are discussed.
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Affiliation(s)
- E Sherwood Brown
- Psychoneuroendocrine Research Program, Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-8849, USA
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Mitchell BM, Webb RC. Impaired vasodilation and nitric oxide synthase activity in glucocorticoid-induced hypertension. Biol Res Nurs 2002; 4:16-21. [PMID: 12363278 DOI: 10.1177/1099800402004001003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Synthetic glucocorticoids are among the most widely prescribed medications by physicians. Although they have a vast array of beneficial effects such as immunosuppression and anti-inflammation, excess glucocorticoids can lead to iatrogenic Cushing's syndrome, which includes hypertension and cardiovascular disease. The exact mechanism by which glucocorticoids elevate blood pressure is not completely understood, but it appears to be a complex pathology that involves increased responsiveness to vasoconstrictors and decreased vasodilator production. Nitric oxide is a vasodilator that plays a key role in blood pressure regulation, and previous studies have shown that a reduction in nitric oxide production or bioavailability contributes to hypertension. Tetrahydrobiopterin, a necessary cofactor for nitric oxide synthase activity, can affect nitric oxide production and bioavailability, with low levels causing decreased nitric oxide production. However, little is known about the interaction between glucocorticoids and tetrahydrobiopterin levels. In this review, the roles of nitric oxide and tetrahydrobiopterin in the pathogenesis of glucocorticoid hypertension will be discussed. Furthermore, the authors propose that glucocorticoids exert a genomic effect to decrease guanosine triphosphate cyclohydrolase I, the rate-limiting enzyme in the production of tetrahydrobiopterin. In the future, tetrahydrobiopterin supplementation in patients with iatrogenic Cushing's syndrome may prove to be beneficial and decrease mortality attributed to cardiovascular disease.
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Affiliation(s)
- Brett M Mitchell
- Department of Physiology at the Medical College of Georgia, Augusta 30912-3000, USA
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17
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Domínguez-Gil B, Espejo B, Muñoz M, Rodicio J, Morales J. Hipertensión arterial después del trasplante renal. HIPERTENSION Y RIESGO VASCULAR 2002. [DOI: 10.1016/s1889-1837(02)71231-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Abstract
Although dermatology now has the most extensive group of systemic medications available for the treatment of skin diseases at any time, GCSs remain the most important agents for managing inflammatory disorders. It is important that the dermatologist have a broad knowledge of guidelines for clinical use, pharmacology, and adverse effects of these drugs. Acute and chronic side reactions should be well recognized. An understanding of the HPA axis and reasons for administering GCSs in different ways is of great value. A good medical history should be taken on any patient treated with GCSs, including knowledge of conditions that would make GCSs inadvisable and other concomitant systemic medications that might produce drug interactions. During the course of therapy, physical examination should include all systems pertinent to side effects caused by these agents, including frequent evaluations of weight and blood pressure. Blood chemistries should be performed on a regular basis, including glucose, electrolytes, and serum lipids. Osteoporosis is one of the most significant adverse affects to be evaluated, with bone mineral density studies recommended on an annual basis for persons continuing on GCS therapy. If hip or other joint pain develops, MR imaging is the most specific and sensitive radiologic examination for evaluating the possibility of osteonecrosis. An ophthalmology examination should be performed every 6 to 12 months to detect early cataract or glaucoma development. Any early signs of infection should be evaluated by appropriate smears, wet preparations, and cultures. Many other studies, including gastrointestinal and pulmonary examinations, may be dictated by specific acute situations. It is important to begin early prevention of the bone loss that occurs with GCS-induced osteoporosis. The 1996 guidelines of the American College of Rheumatology, including adequate calcium and vitamin D intake, should be followed. Hormonal replacement, a bisphosphonate, calcitonin, or a thiazide diuretic may be indicated. Restriction of sodium in the diet is important, as well as adequate potassium intake. The diet should be low in saturated fat and calories and should be high in vegetable protein. Because osteoporosis is so prevalent with GCSs, keeping the patient as active as possible with mild-to-moderate exercise is important. Whenever possible, exposure to persons with infectious processes should be avoided, and proper treatment should be instituted at the initial signs of systemic or cutaneous infection. Oral doses of GCSs are best taken with food to prevent gastrointestinal irritation, and agents for gastric acidity occasionally may be indicated. Significant trauma should be prevented, as should severe exposure to the sun. Many situations may call for consultation with other medical or surgical subspecialists. The patient must be aware of the importance of regular physician evaluations and reporting of any adverse effects while on long-term GCSs. A good relationship and understanding between the patient and physician are vital in minimizing potential problems from these agents. If the dermatologist maintains the proper guidelines of care, patients on GCSs have the highest benefits and lowest risks possible.
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Affiliation(s)
- L C Williams
- Department of Dermatology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
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19
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Sapolsky RM, Romero LM, Munck AU. How do glucocorticoids influence stress responses? Integrating permissive, suppressive, stimulatory, and preparative actions. Endocr Rev 2000; 21:55-89. [PMID: 10696570 DOI: 10.1210/edrv.21.1.0389] [Citation(s) in RCA: 1587] [Impact Index Per Article: 66.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The secretion of glucocorticoids (GCs) is a classic endocrine response to stress. Despite that, it remains controversial as to what purpose GCs serve at such times. One view, stretching back to the time of Hans Selye, posits that GCs help mediate the ongoing or pending stress response, either via basal levels of GCs permitting other facets of the stress response to emerge efficaciously, and/or by stress levels of GCs actively stimulating the stress response. In contrast, a revisionist viewpoint posits that GCs suppress the stress response, preventing it from being pathologically overactivated. In this review, we consider recent findings regarding GC action and, based on them, generate criteria for determining whether a particular GC action permits, stimulates, or suppresses an ongoing stress-response or, as an additional category, is preparative for a subsequent stressor. We apply these GC actions to the realms of cardiovascular function, fluid volume and hemorrhage, immunity and inflammation, metabolism, neurobiology, and reproductive physiology. We find that GC actions fall into markedly different categories, depending on the physiological endpoint in question, with evidence for mediating effects in some cases, and suppressive or preparative in others. We then attempt to assimilate these heterogeneous GC actions into a physiological whole.
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Affiliation(s)
- R M Sapolsky
- Department of Biological Sciences, Stanford University, California 94305, USA
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20
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Abstract
Glucocorticoids play an important role in circulatory homeostasis. They modulate peripheral resistance by their direct action on blood vessels. We have previously shown that glucocorticoids increase preproendothelin-1 gene transcription rate in vascular smooth muscle cells (Morin C et al. 1998, BBRC 244:583). Endothelin-1 is a potent vasoactive peptide involved in the maintenance of vascular tone as well as in pathophysiological states. In this report we show that glucocorticoids increase preproendothelin-1 expression in rat aorta. The rise in preproendothelin-1 steady state mRNA level is dose-dependent with a maximal 2.3-fold stimulation 8 hours following a 0.35 and a 2.5 mg/kg dexamethasone injection. A lower dose of dexamethasone (0.13 mg/kg) also increased preproendothelin-1 expression in rat aorta. Since endothelin-1 levels are regulated at the transcriptional step, the increase in mRNA is likely to be paralleled by increased protein synthesis and vasoconstrictor action. Moreover, systolic blood pressure was significantly elevated in rats who received the 0.35 and 2.5 mg/kg doses of dexamethasone. Together, our results strongly suggest that the increase in preproendothelin-1 expression by glucocorticoids contributes to the regulatory action of these corticosteroids on blood pressure in health and disease.
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Affiliation(s)
- P H Provencher
- Department of Medicine, University of Sherbrooke, QC, Canada
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21
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Morin C, Asselin C, Boudreau F, Provencher PH. Transcriptional regulation of pre-pro-endothelin-1 gene by glucocorticoids in vascular smooth muscle cells. Biochem Biophys Res Commun 1998; 244:583-7. [PMID: 9514952 DOI: 10.1006/bbrc.1998.8300] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Endothelin is a potent vasoactive peptide involved in the maintenance of vascular tone and in pathophysiological states. Endothelin-1 synthesis is controlled at the transcriptional level. We report that glucocorticoids increase the pre-pro-endothelin-1 gene transcription rate in vascular smooth muscle cells. The effect of glucocorticoids is dose-dependent (EC50 approximately 2-3 nM) and completely blocked by co-incubation with the glucocorticoid antagonist RU 38486. The rise in pp-Et-1 steady state mRNA levels is rapid and transient with a maximal three-fold stimulation within one hour of glucocorticoid administration. Glucocorticoid treatment does not affect the half-life of pre-pro-endothelin-1 mRNA as shown by actinomycin D studies. Furthermore, cycloheximide treatment concomitantly with RU 28362 did not reverse the stimulatory effect of glucocorticoids on pre-pro-endothelin-1 mRNA levels. Nuclear run-on analysis shows that glucocorticoids increase the transcription rate of pre-pro-endothelin-1. Our results suggest a role for glucocorticoids in the regulation of biosynthesis and action of this important vasoactive peptide in vascular smooth muscle cells.
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Affiliation(s)
- C Morin
- Department of Medicine, Faculty of Medicine, Sherbrooke University, Quebec, Canada
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22
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Abstract
Atherosclerosis may represent a significant cause of death and morbidity in patients with systemic lupus erythematosus. Coronary involvement is more premature in lupus patients. We present the case of a young woman diagnosed with SLE at the age of 20 years who had a myocardial infarction at age 29 years. We review the mechanisms of atherosclerosis, the interrelations between atherosclerosis and autoimmunity, and between atherosclerosis and SLE. We also review the risk factors, influence of disease and treatment and the guidelines for management of accelerated atherosclerosis in lupus patients.
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Affiliation(s)
- Y Farhey
- Department of Internal Medicine, University of Cincinnati College of Medicine, Ohio 45267-0563, USA
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23
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Kim CY, Imai Y, Itoi K, Hashimoto J, Nobunaga T, Satoh H, Abe K. Analysis of circadian variation of blood pressure and heart rate in dexamethasone-induced hypertensive rats. Clin Exp Hypertens 1996; 18:65-76. [PMID: 8822234 DOI: 10.3109/10641969609082607] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We studied the effect of the chronic oral administration of dexamethasone (dexa) on arterial blood pressure (BP) in conscious rats. Special attention was paid to the effects of dexa on circadian rhythm of BP. As determined by the tail cuff-method, BP in the dexa-treated group was significantly higher than in the control group 24 h after treatment, then increased gradually, reaching a plateau on the 7th day of treatment. At that time, the difference in BP between the two groups was approximately 30 mmHg. When monitored directly and continuously on day 10, mean arterial pressure (MAP) in the dexa-treated group exceeded that of the control group by approximately 15 mmHg throughout the monitoring period. Thus, the circadian rhythm of MAP was sustained in the dexa-treated group, which was in contrast to the previously reported elimination of circadian rhythm in humans. In addition, the increase in BP may have been overestimated by tail-cuff plethysmography, possibly owing to a hightended cardiovascular reactivity to environmental stimuli in dexa-treated animals.
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Affiliation(s)
- C Y Kim
- Department of Environmental Health Sciences, Tohoku University School of Medicine, Sendai, Japan
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24
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Zhu DN, Xue LM, Li P. Cardiovascular effects of microinjection of corticoids and antagonists into the rostral ventrolateral medulla in rats. Blood Press 1995; 4:55-62. [PMID: 7735499 DOI: 10.3109/08037059509077568] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Experiments were performed on Wistar or Sprague-Dawley rats of both sexes. Microinjection of corticosterone (10 or 40 ng/0.1 microliter/site) into the rostral ventrolateral medulla (rVLM) caused an increase in systolic blood pressure (SBP), heart rate (HR) and pressor response induced by stimulation of the dorsal periaqueductal grey (dPAG) in the midbrain. Microinjection of aldosterone (10 or 40 ng/0.1 microliter/site) into the rVLM had similar effects showing a higher level and longer period than that of corticosterone. All these effects were dose-dependent. Microinjection of glucocorticoid antagonist RU 38486 (40 ng/0.1 microliter/site) or mineralocorticoid antagonist spironolactone (40 ng/0.1 microliter/site) caused a decrease in SBP, HR and the pressor response induced by stimulation of the dPAG. The inhibitory effects of spironolactone were more apparent. These results suggest that both corticoids could exert central modulatory effects on the resting cardiovascular activities and facilitate the pressor response during a defense reaction, and the rVLM is an essential area for the location of the central modulation. These effects may play an important role in the incidence and development of hypertension induced by stress.
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Affiliation(s)
- D N Zhu
- Department of Physiology, Shanghai Medical University, China
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25
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Ito Y, Kozawa O, Tokuda H, Suzuki A, Watanabe Y, Kotoyori J, Oiso Y. Glucocorticoid inhibits cAMP production induced by vasoactive agents in aortic smooth muscle cells. Atherosclerosis 1994; 110:69-76. [PMID: 7857372 DOI: 10.1016/0021-9150(94)90069-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
It is well-known that atherosclerotic change and hypertension are common manifestations in patients with glucocorticoid excess. We previously reported that pituitary adenylate cyclase activating polypeptide (PACAP), prostaglandin E2 (PGE2) and carbacyclin, a stable analog of prostacyclin, have suppressive effects on vasopressin-induced DNA synthesis of rat aortic smooth muscle cells through cAMP production (Murase et al., J. Hypertens., 10 (1992) 1505; Oiso et al., Biochem. Cell. Biol., 71 (1993) 156). In the present study, we investigated the effect of glucocorticoid on cAMP production induced by PACAP, PGE2 and carbacyclin in aortic smooth muscle cells. The pretreatment with dexamethasone significantly inhibited cAMP accumulation induced by these vasoactive agents in a dose dependent manner in the range between 10 pM and 10 nM. These inhibitory effects of dexamethasone were dependent on the time of pretreatment up to 8 h. Dexamethasone inhibited cAMP accumulation induced by NaF, a GTP-binding protein activator, and forskolin which directly activates adenylate cyclase. Moreover, forskolin-induced adenylate cyclase activity was significantly reduced in membranes prepared from the cells treated with dexamethasone. These results strongly suggest that glucocorticoid inhibits cAMP production induced by vasoactive agents in primary cultured rat aortic smooth muscle cells and the inhibitory effect is exerted at the level of adenylate cyclase.
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Affiliation(s)
- Y Ito
- First Department of Internal Medicine, Nagoya University School of Medicine, Japan
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26
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Stanimirovic DB, McCarron RM, Spatz M. Dexamethasone down-regulates endothelin receptors in human cerebromicrovascular endothelial cells. Neuropeptides 1994; 26:145-52. [PMID: 8208359 DOI: 10.1016/0143-4179(94)90123-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Human cerebromicrovascular endothelial cells (HBEC) in culture express high affinity ETA receptors coupled to phospholipase C activation. Pretreatment of HBEC with 1 microM dexamethasone for 24 h decreased the number of the ET-1 binding sites (Bmax) on HBEC (96 fmol/mg protein vs 57 fmol/mg protein) without changing the binding affinity (KD) (101 pM vs 92 pM) or displacing profile (ET-1 = ET-2 > ET-3 > S6c). Dexamethasone-pretreated HBEC also exhibited a 40% reduction in the maximal ET-1-stimulated inositol triphosphate (IP3) production, whereas half-maximal stimulatory concentration (EC50) was not affected. This effect of dexamethasone was concentration-dependent, and most pronounced after 24 h of pretreatment. The inhibitory effect of dexamethasone on the ET-1-induced IP3 production was abolished by glucocorticoid-receptor antagonist cortexolone. In contrast, vasopressin-mediated IP3 response in HBEC was not changed by dexamethasone. Cyclo-oxygenase inhibitors indomethacin and acetylsalicylic acid did not influence the ET-1-induced IP3 production by HBEC. The down-regulation of ETA receptors in HBEC by dexamethasone, may represent one of the mechanisms involving the described effects of glucocorticoids on cerebromicrovascular function (i.e. changes in blood brain barrier properties, secretion of vasoactive factors, vascular morphogenesis).
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Affiliation(s)
- D B Stanimirovic
- Stroke Branch, National Institute for Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
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27
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Sapolsky RM, Share LJ. Rank-related differences in cardiovascular function among wild baboons: Role of sensitivity to glucocorticoids. Am J Primatol 1994; 32:261-275. [DOI: 10.1002/ajp.1350320404] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/1993] [Revised: 11/04/1993] [Indexed: 11/10/2022]
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28
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Kennedy B, Elayan H, Ziegler MG. Glucocorticoid hypertension and nonadrenal phenylethanolamine N-methyltransferase. Hypertension 1993; 21:415-9. [PMID: 8458643 DOI: 10.1161/01.hyp.21.4.415] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Several drugs that block epinephrine synthesis by inhibiting phenylethanolamine N-methyltransferase (PNMT) lower blood pressure in hypertensive rats. We investigated the mechanism by which these drugs lower blood pressure in rats made hypertensive with the glucocorticoid dexamethasone. We performed adrenalectomy or sham operation on several rats and then gave them either dexamethasone chronically or vehicle. The dexamethasone-treated adrenalectomized rats also received either the centrally acting PNMT inhibitor SKF 64139 chronically or an equal dose of the primarily peripherally acting PNMT inhibitor SKF 29661. Both SKF 64139 and SKF 29661 reduced blood pressure by more than 25 mm Hg. SKF 64139 also reduced PNMT activity in hypothalamus, medulla oblongata, skeletal muscle, and cardiac atria and ventricles; SKF 29661 inhibited PNMT in muscle and heart tissue by 40-75%, did not inhibit PNMT in hypothalamus, and inhibited PNMT by only 29% in medulla oblongata. PNMT activity in peripheral tissues was also more highly correlated with blood pressure than was PNMT activity in the brain areas studied. Neither drug reduced tissue epinephrine levels, but SKF 64139 elevated dopamine or norepinephrine levels or both in several tissues. We conclude that the blood pressure-lowering action of PNMT-inhibiting drugs in glucocorticoid hypertensive rats may be due to inhibition of peripheral nonadrenal PNMT. We speculate that elevations in nonadrenal PNMT may mediate glucocorticoid hypertension.
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Affiliation(s)
- B Kennedy
- Department of Medicine, University of California, San Diego, Medical Center 92103-8341
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29
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Kanse SM, Takahashi K, Warren JB, Ghatei M, Bloom SR. Glucocorticoids induce endothelin release from vascular smooth muscle cells but not endothelial cells. Eur J Pharmacol 1991; 199:99-101. [PMID: 1893930 DOI: 10.1016/0014-2999(91)90641-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Vascular smooth muscle cells in culture are capable of secreting endothelin which is a vasoconstrictor and mitogenic peptide. The effect of glucocorticoids on endothelin release from vascular smooth muscle cells of the rat and rabbit aortas was investigated. Micromolar concentrations of dexamethasone and cortisol caused a 2 to 5-fold increase in endothelin release from the two smooth muscle cell types but no such response was observed in endothelial cells of the bovine aorta. Glucocorticoids appear to selectively induce endothelin release from vascular smooth muscle cells and this may be relevant to glucocorticoid-induced hypertension.
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Affiliation(s)
- S M Kanse
- Department of Endocrinology, Royal Postgraduate Medical School, London, U.K
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