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Stewart AJ, Ireland JL, Durham AE, McGowan CM. Diagnosis of equine pituitary pars intermedia dysfunction. Vet J 2023; 300-302:106036. [PMID: 37805159 DOI: 10.1016/j.tvjl.2023.106036] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 09/25/2023] [Accepted: 10/04/2023] [Indexed: 10/09/2023]
Abstract
Equine pituitary pars intermedia dysfunction (PPID) is common in aged horses. The majority of horses respond well to treatment, but treatment is lifelong, meaning accurate diagnosis of PPID is important. Similar to any condition, there is no perfect laboratory test to diagnose PPID and accuracy is affected by the characteristics of the population in which the test is being evaluated. This review details the importance of consideration of clinical factors and diagnostic test accuracy. Basal adrenocorticotrophic hormone (ACTH) concentration is used most frequently in practice and has very good diagnostic accuracy when used in combination with clinical judgement and the correct application of diagnostic thresholds. The thyrotropin-releasing hormone stimulation test can be used in horses with equivocal test results following basal ACTH testing, or to evaluate subtle cases due to its improved accuracy.
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Affiliation(s)
| | - Joanne L Ireland
- School of Veterinary Science, Faculty of Health and Life Sciences, The University of Liverpool, Neston CH64 7TE, UK
| | - Andy E Durham
- Liphook Equine Hospital, Liphook, Hampshire GU30 7JG, UK
| | - Catherine M McGowan
- School of Veterinary Science, Faculty of Health and Life Sciences, The University of Liverpool, Neston CH64 7TE, UK.
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2
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Knowles EJ, Hyde C, Harris PA, Elliott J, Menzies-Gow NJ. Short Communication: Identification of equine corticotropin-like intermediate lobe peptide (CLIP) binding to an adrenocortipcotrophic hormone (ACTH) assay capture antibody. Domest Anim Endocrinol 2023; 83:106785. [PMID: 36745973 DOI: 10.1016/j.domaniend.2023.106785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/07/2023] [Accepted: 01/10/2023] [Indexed: 01/18/2023]
Abstract
A chemiluminescent immunoassay is commonly employed to measure adrenocorticotrophic hormone (ACTH) concentrations to assist pituitary pars intermedia dysfunction diagnosis. In a previous study, seasonally-dependent assay cross-reactivity to endogenous equine corticotropin-like intermediate lobe peptide (CLIP, ACTH 18-39) was suspected. The present study aimed to demonstrate binding of endogenous equine CLIP to the capture antibody of the ACTH chemiluminescent immunoassay. Liquid chromatography - mass spectrometry (LCMS) methods were optimised to identify selected ions from synthetic human ACTH, α-melanocyte stimulating hormone (α-MSH, ACTH 1-17) and CLIP. Synthetic ACTH and CLIP bound to the capture antibody of the chemiluminescent ACTH assay, but α-MSH did not. Equine endogenous CLIP was detected by LCMS in pony plasma taken in the autumn and could be eluted from the capture antibody of the ACTH chemiluminescent immunoassay. Further research is required to enable quantification of CLIP. Equine CLIP may alter measured ACTH concentrations in vivo.
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Affiliation(s)
- E J Knowles
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Hatfield, Herts AL9 7TA, UK; Bell Equine Veterinary Clinic, Mereworth, ME18 5GS UK.
| | - C Hyde
- Bio-Analysis Centre, 2 Royal College St, London NW1 0NH, UK
| | - P A Harris
- Waltham Petcare Science Institute, Waltham on the Wold, LE14 4RT, Leicester, UK
| | - J Elliott
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, London, NW1 0TU, UK
| | - N J Menzies-Gow
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Hatfield, Herts AL9 7TA, UK
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3
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Nitzsche AM, Fey K, Büttner K, Gröf M, Staszyk C. The Gingiva of Horses With Pituitary Pars Intermedia Dysfunction: A Macroscopic Anatomical Evaluation. Front Vet Sci 2022; 8:786971. [PMID: 35146012 PMCID: PMC8821874 DOI: 10.3389/fvets.2021.786971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/10/2021] [Indexed: 11/13/2022] Open
Abstract
Pituitary pars intermedia dysfunction (PPID) is a common neurodegenerative disease mainly in horses older than 15 years. The domestic equine population is following the same demographic change as that seen in humans; it is aging and veterinarians are asked to attend to geriatric horses more frequently. Common problems seen regularly in older equines are dental disorders and especially periodontal disease. As a systemic and endocrine disease, associated with delayed wound healing and impaired immune function, PPID should be considered before major dental treatment in aged equines is started. Possible negative effects of PPID on epithelial tissues could also affect the periodontium. Therefore, the aim of the present study was to identify gross changes in the gingiva associated with PPID. Fourteen horses with clinical signs of PPID and adenoma in the pituitary pars intermedia and 13 controls showing neither clinical signs nor PPID-associated histological changes in the pituitary gland were included. PPID-affected horses (26.9 ± 0.73 years) were significantly older than controls (20.0 ± 1.24 years). In the PPID-affected group, significantly more often an irregular and bulky appearance of the gingival texture was observed, as well as an irregular shape of the gingival margin. Furthermore, the sulcus gingivalis of cheek teeth frequently was deeper than 1 mm. These findings indicate a possible association between age, soft tissue alterations, and PPID and suggest a potential predisposition of PPID-affected horses for periodontal diseases.
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Affiliation(s)
- Anne Maria Nitzsche
- Equine Clinic, Internal Medicine, Faculty of Veterinary Medicine, Justus-Liebig-University, Giessen, Germany
- *Correspondence: Anne Maria Nitzsche
| | - Kerstin Fey
- Equine Clinic, Internal Medicine, Faculty of Veterinary Medicine, Justus-Liebig-University, Giessen, Germany
| | - Kathrin Büttner
- Unit for Biomathematics and Data Processing, Faculty of Veterinary Medicine, Justus-Liebig-University, Giessen, Germany
| | - Manuela Gröf
- Faculty of Veterinary Medicine, Institute of Veterinary Pathology, Justus-Liebig-University, Giessen, Germany
| | - Carsten Staszyk
- Faculty of Veterinary Medicine, Institute of Veterinary-Anatomy, -Histology and -Embryology, Justus-Liebig-University, Giessen, Germany
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Hu D, Li J, Zhuang Y, Mao X. Adrenocorticotropic hormone: An expansion of our current understanding of the treatment for nephrotic syndrome. Steroids 2021; 176:108930. [PMID: 34648797 DOI: 10.1016/j.steroids.2021.108930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 09/14/2021] [Accepted: 09/30/2021] [Indexed: 11/26/2022]
Abstract
In clinical practice, we may encounter a treatment dilemma where in some patients with nephrotic syndrome are resistant to glucocorticoids or immunosuppressive agents. Thus, we currently lack viable treatment options and eagerly await the availability of new drugs. Adrenocorticotropic hormone (ACTH) had earlier been used to treat nephrotic syndrome in children, but has now become less popular owing to the advent of oral glucocorticoids. However, in recent studies, ACTH was reportedly used again for treating nephrotic syndrome, reducing proteinuria and protecting renal function, indicating a possibility for its use in the treatment of refractory nephrotic syndrome. This review analysed the validity of ACTH in these studies, focusing on the mechanism of action, application in both paediatric and adult patients with nephrotic syndrome, particularly in children, and possible side effects. We anticipate that our findings will help clinicians in treatment decision-making.
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Affiliation(s)
- Dongxu Hu
- Southwest Medical University, No. 1, Section 1, Xianglin Road, Longmatan District, Luzhou City, Sichuan Province, China
| | - Jiaqin Li
- Southwest Medical University, No. 1, Section 1, Xianglin Road, Longmatan District, Luzhou City, Sichuan Province, China
| | - Yuan Zhuang
- Department of Paediatrics, The Affiliated Hospital of Southwest Medical University, Sichuan Clinical Research Center for Birth Defects, No. 25, Taiping Street, Luzhou City, Sichuan Province, China
| | - Xiaoyan Mao
- Department of Paediatrics, The Affiliated Hospital of Southwest Medical University, Sichuan Clinical Research Center for Birth Defects, No. 25, Taiping Street, Luzhou City, Sichuan Province, China.
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Galinelli NC, Bailey SR, Bamford NJ, Harris PA. Nutritional considerations for the management of equine pituitary
pars intermedia
dysfunction. EQUINE VET EDUC 2021. [DOI: 10.1111/eve.13593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- N. C. Galinelli
- Melbourne Veterinary School The University of Melbourne Parkville Victoria Australia
| | - S. R. Bailey
- Melbourne Veterinary School The University of Melbourne Parkville Victoria Australia
| | - N. J. Bamford
- Melbourne Veterinary School The University of Melbourne Parkville Victoria Australia
| | - P. A. Harris
- Equine Studies Group Waltham Petcare Science Institute Melton Mowbray UK
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Tadros EM, Fowlie JG, Refsal KR, Marteniuk J, Schott HC. Association between hyperinsulinaemia and laminitis severity at the time of pituitary pars intermedia dysfunction diagnosis. Equine Vet J 2018; 51:52-56. [PMID: 29761574 DOI: 10.1111/evj.12963] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 05/04/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND Hyperinsulinaemia is the suspected component of insulin dysregulation having the strongest association with laminitis and occurs variably in equids with pituitary pars intermedia dysfunction (PPID). OBJECTIVES We hypothesised that magnitude of hyperinsulinaemia correlates with laminitis severity in PPID-affected equids. Furthermore, we hypothesised that owners can be unaware of chronic endocrinopathic laminitis. STUDY DESIGN Cross-sectional study. METHODS Serum insulin concentrations, owner-reported laminitis history and radiographic evidence of laminitis were determined in 38 client-owned horses and ponies with confirmed PPID. Laminitis severity was classified into four categories (normal [nonlaminitic], mild, moderate or severe laminitis) based on degree of distal phalangeal rotation. Animals were also categorised as normoinsulinaemic (<20 μU/ml), mildly hyperinsulinaemic (20-50 μU/ml) and severely hyperinsulinaemic (>50 μU/ml). One-way ANOVA, t tests and Fisher's exact tests were performed. RESULTS While owners reported laminitis in 37% of animals, 76% were laminitic based on study criteria (P = 0.01). Owners reported laminitis more frequently in hyperinsulinaemic vs. normoinsulinaemic animals; recognition increased with severity of hyperinsulinaemia (P = 0.03). Mean insulin concentrations were higher in equids with moderate to severe radiographic laminitis (geometric mean 74.1, 95% confidence interval (CI) 38.4-143.1 uU/ml) vs. those classified radiographically as normal to mild (31.9, 95% CI 21.1-48.1 uU/ml P = 0.03). MAIN LIMITATIONS Dynamic insulin testing was not performed; some normoinsulinaemic animals might have had subtle insulin dysregulation. CONCLUSIONS Although radiographic abnormalities were present in most animals at the time of PPID diagnosis, chronic laminitis remained unrecognised by many owners. Owner awareness of laminitis increased with severity of hyperinsulinaemia and higher insulin concentrations were detected in association with more severe radiographic changes. The Summary is available in Chinese - See Supporting Information.
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Affiliation(s)
- E M Tadros
- Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, Michigan, USA
| | - J G Fowlie
- Department of Large Animal Clinical Sciences, Michigan State University, East Lansing, Michigan, USA
| | - K R Refsal
- Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, Michigan, USA
| | - J Marteniuk
- Department of Large Animal Clinical Sciences, Michigan State University, East Lansing, Michigan, USA
| | - H C Schott
- Department of Large Animal Clinical Sciences, Michigan State University, East Lansing, Michigan, USA
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Shipp SL, Smith ML, Gilbert ER, Cline MA. Beta-cell-tropin is associated with short-term stimulation of food intake in chicks. Gen Comp Endocrinol 2015; 224:278-82. [PMID: 26248228 DOI: 10.1016/j.ygcen.2015.08.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 07/20/2015] [Accepted: 08/01/2015] [Indexed: 10/23/2022]
Abstract
Beta-cell-tropin, a peptide derived from adrenocorticotropic hormone, is an insulin secretagogue. When centrally injected, it increases food intake in rats, but its appetite-associated effects have not been reported in any other species. Thus, the present study was designed to evaluate the effects of central beta-cell-tropin on appetite-associated parameters in an alternative vertebrate model, the chick. Central injection of 2 or 4 nmol beta-cell-tropin increased food intake for 60 min. Whole hypothalamus was collected at 60 min post-injection, and real-time PCR performed to measure mRNA abundance of agouti-related peptide, corticotropin releasing factor, galanin, melanin concentrating hormone, neuropeptide Y, orexin, prohormone convertase 2, pro-opiomelanocortin, peroxisome proliferator-activated receptor γ, urotensin 2, and visfatin, not one of which were affected by beta-cell-tropin treatment. Results demonstrate that beta-cell-tropin is associated with short-term stimulation of food intake.
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Affiliation(s)
- Steven L Shipp
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Marissa L Smith
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Elizabeth R Gilbert
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Mark A Cline
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
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van de Logt AE, Beerenhout CH, Brink HS, van de Kerkhof JJ, Wetzels JF, Hofstra JM. Synthetic ACTH in High Risk Patients with Idiopathic Membranous Nephropathy: A Prospective, Open Label Cohort Study. PLoS One 2015; 10:e0142033. [PMID: 26562836 PMCID: PMC4642982 DOI: 10.1371/journal.pone.0142033] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 10/12/2015] [Indexed: 11/19/2022] Open
Abstract
New therapeutic agents are warranted in idiopathic membranous nephropathy. Synthetic ACTH may be advantageous with reported remission rates up to 85% and few side effects. We conducted a prospective open label cohort study from 2008 till 2010 (NCT00694863). We prospectively selected patients with idiopathic membranous nephropathy and high risk for progression (defined as βeta-2-microglobulin (β2m) excretion of >500 ng/min). For comparison, we selected matched historical controls treated with cyclophosphamide. The prospectively selected patients received intramuscular injections of synthetic ACTH during 9 months (maximal dose 1 mg twice a week). The primary endpoints concerned the feasibility and incidence of remissions as a primary event. Secondary endpoints included side effects of treatment and the incidence of remissions and relapses at long-term follow-up. Twenty patients (15 men) were included (age 54±14 years, serum creatinine 104 μmol/l [IQR 90–113], urine protein:creatinine ratio 8.7 g/10 mmol creatinine [IQR 4.3–11.1]). Seventeen patients (85%) completed treatment. 97% of injections were administered correctly. Cumulative remission rate was 55% (complete remission in 4 patients, partial remission 7 patients). In a group of historical controls treated with cyclophosphamide and steroids, 19 of 20 patients (95%) developed a remission (complete remission in 13 patients, partial remission in 6 patients) (p<0.01). The main limitation of our study is its small size and the use of a historical control group. We show that treatment with intramuscular injections of synthetic ACTH is feasible. Our data suggest that synthetic ACTH is less effective than cyclophosphamide in inducing a remission in high risk patients with idiopathic membranous nephropathy. The use of synthetic ACTH was also associated with many adverse events. Therefore, we advise against synthetic ACTH as standard treatment in membranous nephropathy.
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Affiliation(s)
- Anne-Els van de Logt
- Radboud university medical center, Radboud Institute for Health Sciences, Department of Nephrology, Nijmegen, The Netherlands
- * E-mail:
| | | | - Hans S. Brink
- Medisch Spectrum Twente, Department of Internal Medicine, Enschede, The Netherlands
| | | | - Jack F. Wetzels
- Radboud university medical center, Radboud Institute for Health Sciences, Department of Nephrology, Nijmegen, The Netherlands
| | - Julia M. Hofstra
- Radboud university medical center, Radboud Institute for Health Sciences, Department of Nephrology, Nijmegen, The Netherlands
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Lorusso P, Bottai A, Mangione E, Innocenti M, Cupisti A, Egidi MF. Low-dose synthetic adrenocorticotropic hormone-analog therapy for nephrotic patients: results from a single-center pilot study. Int J Nephrol Renovasc Dis 2015; 8:7-12. [PMID: 25709493 PMCID: PMC4327400 DOI: 10.2147/ijnrd.s74349] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
INTRODUCTION This report describes our experience using a low-dose synthetic adrenocorticotropic hormone (ACTH) analog for patients affected by nephrotic syndrome who had not responded to or had relapsed after steroid and immunosuppressive treatments. PATIENTS AND METHODS Eighteen adult nephrotic patients with an estimated glomerular filtration rate >30 mL/min were recruited. Histological pictures included ten of membranous nephropathy, three of membranous proliferative glomerulonephritis, three of minimal change, and two of focal segmental glomerular sclerosis. All patients received the synthetic ACTH analog tetracosactide 1 mg intramuscularly once a week for 12 months. Estimated glomerular filtration rate, proteinuria, serum lipids, albumin, glucose, and potassium were determined before and during the treatment. RESULTS One of the 18 patients discontinued the treatment after 1 month because of severe fluid retention, and two patients were lost at follow-up. Complete remission occurred in six cases, while partial remission occurred in four cases (55.5% responder rate). With respect to baseline, after 12 months proteinuria had decreased from 7.24±0.92 to 2.03±0.65 g/day (P<0.0001), and serum albumin had increased from 2.89±0.14 to 3.66±0.18 g/dL (P<0.0001). Total and low-density lipoprotein cholesterol had decreased from 255±17 to 193±10 mg/dL (P=0.01), and from 168±18 to 114±7 mg/dL (P=0.03), respectively. No cases of severe worsening of renal function, hyperglycemia, or hypokalemia were observed, and no admissions for cardiovascular or infectious events were recorded. CONCLUSION Tetracosactide administration at the dosage of 1 mg intramuscularly per week for 12 months seems to be an acceptable alternative for nephrotic patients unresponsive or relapsing after steroid-immunosuppressive regimens. Further studies should be planned to assess the effect of this low-dose ACTH regimen also in nephrotic patients not eligible for kidney biopsy or immunosuppressive protocols.
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Affiliation(s)
- Paolo Lorusso
- Nephrology Transplant Dialysis Unit (AOUP), Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Anna Bottai
- Nephrology Transplant Dialysis Unit (AOUP), Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Emanuela Mangione
- Nephrology Transplant Dialysis Unit (AOUP), Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Maurizio Innocenti
- Nephrology Transplant Dialysis Unit (AOUP), Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Adamasco Cupisti
- Nephrology Transplant Dialysis Unit (AOUP), Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Maria Francesca Egidi
- Nephrology Transplant Dialysis Unit (AOUP), Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
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McFarlane D. Pathophysiology and clinical features of pituitarypars intermediadysfunction. EQUINE VET EDUC 2014. [DOI: 10.1111/eve.12237] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- D. McFarlane
- Center for Veterinary Health Sciences; Oklahoma State University; Stillwater USA
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Gehlen H, May A, Bradaric Z. Comparison of Insulin and Glucose Metabolism in Horses with Pituitary Pars Intermedia Dysfunction Treated Versus Not Treated with Pergolide. J Equine Vet Sci 2014. [DOI: 10.1016/j.jevs.2013.11.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Gong R. Leveraging melanocortin pathways to treat glomerular diseases. Adv Chronic Kidney Dis 2014; 21:134-51. [PMID: 24602463 DOI: 10.1053/j.ackd.2013.09.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 09/30/2013] [Accepted: 09/30/2013] [Indexed: 12/22/2022]
Abstract
The melanocortin system is a neuroimmunoendocrine hormone system that constitutes the fulcrum in the homeostatic control of a diverse array of physiological functions, including melanogenesis, inflammation, immunomodulation, adrenocortical steroidogenesis, hemodynamics, natriuresis, energy homeostasis, sexual function, and exocrine secretion. The kidney is a quintessential effector organ of the melanocortin hormone system with melanocortin receptors abundantly expressed by multiple kidney parenchymal cells, including podocytes, mesangial cells, glomerular endothelial cells, and renal tubular cells. Converging evidence unequivocally demonstrates that the melanocortin-based therapy using the melanocortin peptide adrenocorticotropic hormone (ACTH) is prominently effective in inducing remission of steroid-resistant nephrotic syndrome caused by various glomerular diseases, including membranous nephropathy, minimal change disease and focal segmental glomerulosclerosis, suggesting a steroidogenic-independent mechanism. Mechanistically, ACTH and other synthetic melanocortin analogues possess potent proteinuria-reducing and renoprotective activities that could be attributable to direct protection of glomerular cells and systemic immunomodulation. Thus, leveraging melanocortin signaling pathways using ACTH or novel synthetic melanocortin analogues represents a promising and pragmatic therapeutic strategy for glomerular diseases. This review article introduces the biophysiology of the melanocortin hormone system with an emphasis on the kidney as a target organ, discusses the existing data on melanocortin therapy for glomerular diseases, and elucidates the potential mechanisms of action.
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Taraphder A. Adrenocorticotropic hormone (ACTH): A forgotten tool in the treatment of proteinuric nephropathies. APOLLO MEDICINE 2013. [DOI: 10.1016/j.apme.2013.01.005] [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] Open
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Abstract
Refractory nephrotic syndrome continues to be a therapeutic challenge despite advances in immunosuppression and blockade of the renin-angiotensin-aldosterone cascade. Adrenocorticotropic hormone (ACTH), a pituitary neuroimmunoendocrine polypeptide, was widely used in the 1950s as an effective therapy for childhood nephrotic syndrome, but has since been replaced by synthetic glucocorticoid analogues. In addition to controlling steroidogenesis, ACTH also acts as an important physiological agonist of the melanocortin system. Clinical and experimental evidence now suggests that ACTH has antiproteinuric, lipid-lowering and renoprotective properties, which are not fully explained by its steroidogenic effects. ACTH therapy is effective in inducing remission of nephrotic syndrome in patients with a variety of proteinuric nephropathies, even those resistant to steroids and other immunosuppressants. This Perspectives article describes the biophysiology of ACTH, with an emphasis on its melanocortin actions, particularly in renal parenchymal cells, which could potentially explain the therapeutic effects of ACTH in nephrotic glomerulopathies.
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Affiliation(s)
- Rujun Gong
- Division of Kidney Disease and Hypertension, Department of Medicine, Rhode Island Hospital, Brown University School of Medicine, 593 Eddy Street, Providence, RI 02903, USA.
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15
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Abstract
Equine pituitary pars intermedia dysfunction (PPID), also known as equine Cushing's syndrome, is a widely recognized disease of aged horses. Over the past two decades, the aged horse population has expanded significantly and in addition, client awareness of PPID has increased. As a result, there has been an increase in both diagnostic testing and treatment of the disease. This review focuses on the pathophysiology and clinical syndrome, as well as advances in diagnostic testing and treatment of PPID, with an emphasis on those findings that are new since the excellent comprehensive review by Schott in 2002.
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Affiliation(s)
- Dianne McFarlane
- Department of Physiological Sciences, 264 McElroy Hall, Oklahoma State University, Stillwater, OK 74078, USA.
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16
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Abstract
PPID in older equids has become a major health concern of horse owners. In response, equine practitioners have made greater efforts at understanding, diagnosing, and treating this disorder. Although PPID is recognized to be a different form of pituitary-dependent hyperadrenocorticism than is seen in canine or human patients, relatively little is known about the pathophysiology and natural progression of the disease. At present, the diagnosis is best supported by manifestation of characteristic clinical signs and endocrinologic test results, preferably a supportive DST result. Treatment must focus on improving overall health care, including body clipping, dentistry, and nutrition. As the condition progresses, administration of pergolide or a combination of pergolide and cyproheptadine is currently considered the best medical treatment. The time point at which medication should be added to improved health care and management changes is not currently known, but loss of body condition and development of hyperglycemia suggest more advanced PPID that would likely benefit from drug therapy. Whether medical treatment needs to be continuous or could be intermittent is also unknown. As the demand for treatment of affected equids continues to increase, clinical response and endocrinologic testing data as well as pharmacologic data for currently used drugs and other agents should be expected. Similarly, novel medical, and perhaps surgical, treatment strategies for this condition should also be anticipated in the future.
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Affiliation(s)
- Harold C Schott
- Department of Large Animal Clinical Sciences, D-202 Veterinary Medical Center, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824-1314, USA.
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17
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Cooper GJS. Amylin and Related Proteins: Physiology and Pathophysiology. Compr Physiol 2001. [DOI: 10.1002/cphy.cp070210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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18
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Lincoln GA, Rhind SM, Pompolo S, Clarke IJ. Hypothalamic control of photoperiod-induced cycles in food intake, body weight, and metabolic hormones in rams. Am J Physiol Regul Integr Comp Physiol 2001; 281:R76-90. [PMID: 11404281 DOI: 10.1152/ajpregu.2001.281.1.r76] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study used a hypothalamo-pituitary disconnected (HPD) sheep model to investigate the central regulation of long-term cycles in voluntary food intake (VFI) and body weight (BW). VFI, BW, and circulating concentrations of metabolic hormones [alpha-melanocyte-stimulating hormone (alpha-MSH), insulin-like growth factor-1 (IGF-1), insulin, and leptin] were measured in HPD and control Soay rams exposed to alternating 16 weekly periods of long and short days for 80 wk. In the controls, the physiology was cyclical with a 32-wk periodicity corresponding to the lighting regimen. VFI and BW increased under long days to a maximum early into short days, and there were associated increases in blood concentrations of alpha-MSH, insulin, and leptin. In the HPD rams, there were no significant photoperiod-induced changes in any of the parameters. VFI increased after surgery for 8 wk and then gradually declined, although BW increased progressively and the HPD rams became obese. Concentrations of alpha-MSH, insulin, and leptin in peripheral blood were permanently increased (>200%), and levels of IGF-1 decreased (<55%). The HPD lesion effectively destroyed the entire median eminence [no nerve terminals immunostained for tyrosine hydroxylase (TH) and gonadotropin-releasing hormone] and the adjacent arcuate nucleus (no perikarya immunostained for proopiomelanocortin or TH, and no cells expressed neuropeptide Y mRNA). The results support the conclusion that arcuate hypothalamic systems generate long-term rhythms in VFI, BW, and energy balance.
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Affiliation(s)
- G A Lincoln
- Medical Research Council Human Reproductive Sciences Unit, Centre for Reproductive Biology, Edinburgh EH3 9ET, United Kingdom
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Lincoln GA, Richardson M. Photo-neuroendocrine control of seasonal cycles in body weight, pelage growth and reproduction: lessons from the HPD sheep model. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART C, PHARMACOLOGY, TOXICOLOGY & ENDOCRINOLOGY 1998; 119:283-94. [PMID: 9827001 DOI: 10.1016/s0742-8413(98)00017-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
This chapter summarises the results of a recent study which investigated the role of the hypothalamo-pituitary relay system in mediating the effects of photoperiod on seasonal cycles in: (a) body weight; (b) pelage growth; and (c) reproduction in Soay rams. Hypothalamo-pituitary disconnected (HPD) and the control rams were housed indoors under an artificial lighting regimen of alternating 16-weekly periods. These periods consisted of long (16L:8D) and short days (8L:16D) and lasted for more than 2 years. The: (i) body weight; (ii) voluntary food intake; (iii) pelage and horn growth; and (iv) variations in testicular diameter were measured routinely every 2-4 weeks. Twice-weekly blood samples were collected to monitor long-term changes in the blood concentrations of: (1) pituitary; (2) metabolic; and (3) reproductive hormones (prolactin, GH, alpha-MSH, beta-endorphin, ACTH, TSH, LH, FSH, cortisol, insulin, IGF1 and testosterone). In control rams there were clearly defined photoperiod-induced cycles in blood concentrations of prolactin, alpha-MSH, beta-endorphin, LH, FSH, insulin and testosterone and associated morphological changes consistent with causal relationships (e.g. prolactin versus wool and horn growth, alpha-MSH, beta-endorphin and insulin versus body weight/food intake, LH and FSH versus testis size). In the HPD rams there were no photoperiod-induced cycles in the concentrations of any of the pituitary hormones with the exception of prolactin which varied as in controls (10-fold higher under long days). There was a permanent increase in blood concentrations of alpha-MSH, beta-endorphin and insulin in the HPD animals and a decrease in the concentrations of GH (loss of pulsatility) and IGF1. These changes were associated with the development of obesity. The reproductive axis was inactivated (basal LH, FSH and testosterone) although there was residual cyclicity in the size of the testis associated with the changes in prolactin secretion. Overall, the results support the view that the melatonin signal which encodes photoperiod, acts in the hypothalamus to regulate some photoperiodic responses (alpha-MSH and beta-endorphin-body weight axis, gonadotrophin-gonadal axis) but acts in the pituitary gland to regulate other responses (prolactin-pelage axis). However, a functional hypothalamus is required to generate normal seasonal cycles in: (a) body weight; (b) food intake; (c) growth; (d) fattening; and (e) reproduction, to provide the internal coordination between different systems and to facilitate the temporal entrainment to environmental cues.
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Affiliation(s)
- G A Lincoln
- MRC Reproductive Biology Unit, Centre for Reproductive Biology, Edinburgh, UK
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Morris HR, Paxton T, Panico M, McDowell R, Dell A. A novel geometry mass spectrometer, the Q-TOF, for low-femtomole/attomole-range biopolymer sequencing. JOURNAL OF PROTEIN CHEMISTRY 1997; 16:469-79. [PMID: 9246631 DOI: 10.1023/a:1026309410737] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Ultra-high-sensitivity, biopolymer sequencing is a goal in many fields of molecular biology, and collisionally activated decomposition electrospray mass spectrometry (CAD ES MS/MS) using a triple quadrupole mass spectrometer has become a method of choice for work in the high- to mid-femtomole range. However, when the detection of ions becomes statistical, as it may in that range, the mass assignment of fragment ions is inaccurate and either sequencing becomes impossible or ambiguities result due, for example, to the closeness in amino acid residue masses (I/L, N or K/Q, E). Some ambiguities may be resolved by synthesizing possible sequences, but this is unsatisfactory. In considering the limitations of triple quadrupole MS/MS with respect to scanning ion detection, resolution, transmission, and mass accuracy, we reasoned that a novel geometry quadrupole orthogonal acceleration time-of-flight (Q-TOF) instrument would have special merit for ultra-high-sensitivity MS/MS sequencing, and suggested its construction for this purpose some three years ago. A prototype Q-TOF has now been built by Micromass [Morris et al. (1996), Rapid Commun. Mass Spectrom. 10, 889-896], and in the first research on the instrument, including MHC antigen and filarial nematode glycoprotein studies, we demonstrate low-femtomole- and attomole-range sequencing with mass accuracy of better than 0.1 Da throughout the daughter-ion spectrum, thus removing sequencing ambiguities in some of the most challenging work demanding the highest sensitivity.
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Affiliation(s)
- H R Morris
- Department of Biochemistry, Imperial College, London, United Kingdom
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21
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Bobbioni-Harsch E, Frütiger S, Hughes G, Panico M, Etienne A, Zappacosta F, Morris HR, Jeanrenaud B. Physiological concentrations of oxytocin powerfully stimulate insulin secretionin vitro. Endocrine 1995; 3:55-9. [PMID: 21153237 DOI: 10.1007/bf02917449] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/1994] [Accepted: 09/20/1994] [Indexed: 11/29/2022]
Abstract
The effect of natural oxytocin on insulin secretion was investigated by using isolated, perfused rat pancreases. Oxytocin produced a dose-dependent stimulation of insulin secretion starting with a concentration as low as 2.3PM: and with a maximal effect obtained at 66PM: . Specific oxytocin antagonist, desGly-NH(2) (9), d(CH(2))(5) [Tyr (Me)(2), Thr(4)] OVT, reduced by 70% the stimulatory effect of 66PM: natural oxytocin. A specific oxytocin receptor agonist OH(Thr(4), Gly(7))OT showed an insulinotropic action similar to equivalent amounts of oxytocin. Replacement or modifications of Q(4), L(8) or the NH(2) terminal group in the oxytocin molecule reduced or abolished the biological activity. This study demonstrated that: (1) in normal rat pancreas, oxytocin stimulates insulin secretion at concentrations similar to those present in the plasma; (2) oxytocin exerts this secretagogue action in presence of basal physiological glucose levels (5 mM); (3) oxytocin stimulates insulin secretion by interacting with its own receptor. A potential role for oxytocin as an insulin-releasing hormone is thus conceivable.
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Affiliation(s)
- E Bobbioni-Harsch
- Laboratories de Recherches Métaboliques of the Geneva Faculty and Department of Medicine, Geneva
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22
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Eagle L, Morton J, Dunmore S. Effect of dopamine on the secretion and processing of beta-cell tropin from isolated pituitary neurointermediate lobes of mice. Ann N Y Acad Sci 1993; 680:499-501. [PMID: 8390177 DOI: 10.1111/j.1749-6632.1993.tb19720.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- L Eagle
- Clore Laboratory, University of Buckingham, United Kingdom
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23
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Davenport M, Morton JL, Beloff-Chain A, Dunmore SJ, Cawthorne MA. The effects of insulin and the pituitary peptide beta-cell tropin on the incorporation of D-3-3H-glucose into lipid in brown adipocytes from lactating and non-lactating rats. Biochem Biophys Res Commun 1991; 181:1437-41. [PMID: 1662498 DOI: 10.1016/0006-291x(91)92100-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Lactating and non-lactating rat brown adipocytes were used to study the dose-dependent stimulation of lipogenesis by Beta-cell tropin (BCT) and insulin. In non-lactating animals BCT increased lipogenesis approximately 2-fold compared to a 3-fold stimulation with insulin; however BCT was effective at a substantially lower molar concentration than insulin. In lactating animals resistance was observed to both BCT and insulin action.
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Affiliation(s)
- M Davenport
- Clore Laboratory for the Biological Sciences, University of Buckingham, Bucks, U.K
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24
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Morton JL, Davenport M, Dunmore SJ. Plasma B-cell tropin (ACTH22-39) concentration in lean and obese (ob/ob) mice and lean and obese (fa/fa) Zucker rats. Biochem Biophys Res Commun 1991; 174:767-71. [PMID: 1847053 DOI: 10.1016/0006-291x(91)91483-s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A method has been developed for the measurement of plasma concentrations of Beta-cell tropin (BCT), which is a potent insulinotropic and lipogenic peptide secreted by the pituitary. The method was employed to compare plasma Beta-cell tropin concentrations between lean and genetically obese (ob/ob) mice and between lean and genetically obese (fa/fa) Zucker rats. The plasma concentration in lean mice was 0.17 +/- 0.02 (5)nmole/l (mean +/- SEM, n = 5), while that in obese (ob/ob) mice was significantly higher, being 2.88 +/- 1.13 (5)nmole/l. The plasma BCT concentration in Zucker rats was 0.14 +/- 0.02 (15)nmole/l, while that in obese Zucker (fa/fa) rats was significantly higher, being 1.69 +/- 0.72 (16)nmole/l. These results explain previously observed differences in the Beta-cell tropin-like biological activity in plasma from lean and obese animals, and support the hypothesis that the peptide has a role in the development of hyperinsulinaemia and obesity.
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Affiliation(s)
- J L Morton
- Clore Laboratory for the Biological Sciences, University of Buckingham, U.K
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25
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Bobbioni-Harsch E, Jeanrenaud B. The hypothalamic origin of an insulin secretion promoting factor present in the plasma of normal rats. J Neuroendocrinol 1989; 1:103-8. [PMID: 19210466 DOI: 10.1111/j.1365-2826.1989.tb00087.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Abstract Hypothalamic and plasma extracts from normal rats both contain a factor whose property is to stimulate insulin secretion. The two factors have many characteristics in common. Both are active in vivo (when administered to normal recipient rats) and in vitro (when infused into perfused rat pancreases). Both are inactivated by HCI hydrolysis. Both elute at the same ratio between elution volume of the peaks and void volume after gel-chromatographies are carried out, first on Sephadex G-50, then on Biogel P-2, indicating that they have a similar molecular weight which ranges between 800 and 1,200 Daltons. When anaesthetized rats are submitted to an acute bilateral electrical stimulation of the lateral hypothalamus, the insulin secretion stimulating activity present in the plasma is enhanced compared to that measured in sham-stimulated control rats. Conversely, the insulin secretion promoting activity is decreased in plasma from rats whose ventral hypothalamus is acutely and electrolytically lesioned. These data indicate that, in normal rats, the hypothalamus contains an insulin secretion promoting factor that is releasable in the plasma.
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Affiliation(s)
- E Bobbioni-Harsch
- Laboratoires de Recherches Métaboliques, Faculty and Department of Medicine, Geneva University, Avenue de la Roseraie 64, 1211 Geneva 4, Switzerland
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26
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Bray GA, York DA, Fisler JS. Experimental obesity: a homeostatic failure due to defective nutrient stimulation of the sympathetic nervous system. VITAMINS AND HORMONES 1989; 45:1-125. [PMID: 2688303 DOI: 10.1016/s0083-6729(08)60393-3] [Citation(s) in RCA: 142] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The basic hypothesis of this review is that studies on models of experimental obesity can provide insight into the control systems regulating body nutrient stores in humans. In this homeostatic or feedback approach to analysis of the nutrient control system, we have examined the afferent feedback signals, the central controller, and the efferent control elements regulating the controlled system of nutrient intake, storage, and oxidation. The mechanisms involved in the beginning and ending of single meals must clearly be related to the long-term changes in fat stores, although this relationship is far from clear. Changes in total nutrient storage in adipose tissue can arise as a consequence of changes in the quantity of nutrients ingested in one form or another or a decrease in the utilization of the ingested nutrients. A change in energy intake can be effected by increased size of individual meals, increased number of meals in a 24-hour period, or a combination of these events. Similarly, a decrease in utilization of these nutrients can develop through changes in resting metabolic energy expenditure which are associated with one of more of the biological cycles such as protein metabolism, triglyceride for glycogen synthesis and breakdown, or maintenance of ionic gradients for Na+ + K+ across cell walls. In addition, differences in energy expenditure related to the thermogenesis of eating or to the level of physical activity may account for differences in nutrient utilization.
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McDermott JR, Biggins JA, Smith AI, Gibson AM, Keith AB, Edwardson JA. Removal of Arg1 and Phe22 from CLIP (ACTH18-39) by rodent pituitary and blood peptidases. Peptides 1988; 9:757-61. [PMID: 2852359 DOI: 10.1016/0196-9781(88)90118-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The major product on incubation of CLIP (ACTH18-39) with rat and mouse serum, rat plasma and whole blood, and soluble extracts of rat pituitary is [des-Arg1]-CLIP (ACTH19-39) while [des-Phe22]-CLIP (ACTH18-38) is the major product with pituitary particulate fraction. In both cases, p-chloromercuribenzoate-sensitive, metal-dependent peptidase activity appears to be responsible for the cleavage. The serum enzyme may be related to proline aminopeptidase. Material coeluting with [des-Arg]-CLIP on two HPLC solvent gradients is present in the superfusion media from neurointermediate lobes of genetically obese (ob/ob) mice but is not present in acid extracts of the lobe. This suggests that postsecretory processing of CLIP may involve removal of the N-terminal Arg residue.
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Affiliation(s)
- J R McDermott
- MRC Neuroendocrinology Unit, Newcastle General Hospital
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28
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Abstract
Central injection of thyrotropin-releasing hormone (TRH) prevented the rise in plasma glucose due to clonidine challenge in mice. This antihyperglycemic action was dose-related, dependent upon the structural integrity of the peptide, dissociated from the peptide's hypophysiotropic influences, and coupled to reversal of clonidine's suppressive action of insulin release. TRH was effective in preventing the rise in plasma glucose when given at different times before clonidine (up to two hours), and it also reversed the hyperglycemia when administered 30 min after clonidine, when plasma glucose was already exceedingly high. The results suggest that TRH is able to physiologically oppose clonidine-induced hyperglycemia by acting in a specific and durable manner upon central mechanisms which modulate insulin secretion.
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Affiliation(s)
- S Amir
- Center for Neurosciences and Behavioral Research, Weizmann Institute of Science, Rehovot, Israel
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29
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Larsson LI. Regulatory peptides and amines during ontogeny and in non-endocrine cancers: occurrence and possible functional significance. PROGRESS IN HISTOCHEMISTRY AND CYTOCHEMISTRY 1988; 17:1-222. [PMID: 3062670 DOI: 10.1016/s0079-6336(88)80008-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- L I Larsson
- Department of Molecular Cell Biology, State Serum Institute, Copenhagen S/Denmark
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30
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Amir S, Harel M, Rivkind AI. Thyrotropin-releasing hormone potently reverses epinephrine-stimulated hyperglycemia in mice. Brain Res 1987; 435:112-22. [PMID: 3123010 DOI: 10.1016/0006-8993(87)91592-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Intracerebroventricular microinjection of thyrotropin-releasing hormone (TRH) potently blocked the development of, as well as promptly reversed, epinephrine-stimulated hyperglycemia in mice. The central antihyperglycemic effect was dose-related (0.1-10 micrograms), could be reproduced by an intravenous injection of a large dose of the peptide (100 micrograms), was independent of experimental factors such as stress and age, was effective against other hyperglycemic stimuli, and appeared to be unique to TRH, as it could not be mimicked by many other centrally active peptides known to influence glucoregulation in normoglycemic animals. Moreover, the antihyperglycemic effect of TRH appeared to depend on the structural integrity of the peptide molecule but seemed to be unrelated to the peptide's hypophysiotropic actions or to interaction of the peptide with previously characterized TRH receptors, as it could be mimicked by various analogs devoid of thyrotropin- and prolactin-releasing influences or by peptides resembling TRH in amino acid composition but lacking substantial binding affinity to TRH receptors. Furthermore, the effect of TRH to reverse epinephrine-stimulated hyperglycemia appeared to be mediated by combined action of peripheral sympathetic and parasympathetic mechanisms to stimulate insulin release from the pancreas, since only complete blockade of the central autonomic outflow, but not selective perturbation of the sympathetic or parasympathetic outflow, or depletion of pancreatic insulin could substantially attenuate the antihyperglycemic action. Taken together, these results suggest a new physiologic role of TRH as a central glucoregulatory neuropeptide involved in autonomic modulation of insulin secretion and prevention of hyperglycemia.
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Affiliation(s)
- S Amir
- Center for Neurosciences and Behavioral Research, Weizmann Institute of Science, Rehovot, Israel
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Suzuki F, Kato K, Kato T, Ogasawara N. S-100 protein in clonal astroglioma cells is released by adrenocorticotropic hormone and corticotropin-like intermediate-lobe peptide. J Neurochem 1987; 49:1557-63. [PMID: 2822856 DOI: 10.1111/j.1471-4159.1987.tb01027.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
S-100 protein in clonal GA-1 and C6 rat glioma cell lines was released in serum-free medium supplemented with adrenocorticotropic hormone (ACTH). The induction of S-100 protein release by ACTH was dose-dependent, showing a half-maximal release at about 5 microM, and the S-100 protein concentration in the medium increased sharply within 3 min, but slightly during further incubation. The S-100 protein release was apparently accompanied by a decrease in the membrane-bound form of S-100 protein in the cell. The S-100 protein release was induced not by the ACTH1-24 fragment, which exhibits the known effects of ACTH, but by the ACTH18-39 fragment, which is designated as corticotropin-like intermediate-lobe peptide (CLIP). These results indicate that the C-terminal half of ACTH is responsible for the S-100 protein release. The enhancement of S-100 protein release by ACTH was also observed in normal rat glioblasts. The release induced by ACTH was apparently specific to S-100 protein, because little release of the cytoplasmic enzymes, creatine kinase, and enolase was observed under the same conditions. High concentrations (5 mM) of dibutyryl cyclic AMP or dibutyryl cyclic GMP were also found to induce S-100 protein release; however, catecholamines (epinephrine, norepinephrine, isoproterenol, and dopamine), acetylcholine, and glutamic acid did not enhance the release.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- F Suzuki
- Department of Biochemistry, Aichi Prefectural Colony, Japan
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Dunmore SJ, Panico M, Etienne AT, Morris HR, Beloff-Chain A. The effects of structural modifications on the insulin-releasing activity of beta-cell-tropin. Biochem J 1987; 244:797-800. [PMID: 2833221 PMCID: PMC1148067 DOI: 10.1042/bj2440797] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The minimal effective concentration of the pituitary insulin secretagogue beta-cell-tropin (beta-CT) on the in vitro perfused pancreas was established and the effects of various modifications of the peptide on its potency were tested: iodination with 127I and acetylation reduced the insulin-releasing activity of beta-cell-tropin, and the C-terminal fragments beta-CT-(2-18), beta-CT-(3-18) and beta-CT-(6-18) were all less potent than the intact molecule; beta-CT-(1-6) was not active and did not inhibit beta-CT-induced insulin release.
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Affiliation(s)
- S J Dunmore
- Department of Biochemistry, Imperial College, London, U.K
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33
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Pokrovskii VA, Mosin VV. Fast atom bombardment in mass spectrometry: Method and applications. THEOR EXP CHEM+ 1987. [DOI: 10.1007/bf00534977] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Chapter 9 The neuropeptide concept. PROGRESS IN BRAIN RESEARCH 1987. [DOI: 10.1016/s0079-6123(08)60199-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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Abstract
The occurrence of intermediates from the processing of ACTH-(1-39) [adrenocorticotropic hormone-(1-39)] to alpha-melanocyte-stimulating hormone was investigated in normal pig pituitaries by the use of sensitive and specific radioimmunoassays for ACTH-(1-13), ACTH-(1-14), ACTH-(1-13)-NH2 and ACTH-(1-39). Fractionation by reverse-phase h.p.l.c. revealed ACTH(1-17) and their acetylated analogues. The intermediate lobe contained NO-diacetyl-ACTH-(1-13)-NH2, N-acetyl-ACTH-(1-13)-NH2 and ACTH-(1-13)-NH2. In addition, the corresponding ACTH-(1-14) peptides (the glycine-extended precursor of the amidated peptides) were detected in lower amounts in both the intermediate lobe and the anterior lobe. ACTH-(1-17), ACTH-(1-13) and their acetylated analogues could not be detected in the anterior lobe or the intermediate lobe. The results suggest that an endopeptidase initially cleaves ACTH-(1-39) at the Lys-16-Arg-17 bond. ACTH-(1-16) is then processed by a pituitary carboxypeptidase to ACTH-(1-14) and ACTH-(17-39) by the aminopeptidase to ACTH-(18-39).
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Abstract
Obesity as a common disorder of lipid metabolism might be caused by defective hypothalamic control as demonstrated by ventromedial lesions or the effect of cholecystokinin application. The hypothalamic proopiomelanocorticotropin is the precursor of hormonal fragments affecting fat mobilisation, the endocrine pancreas and gastrointestinal functions.
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Jeanrenaud B, Halimi S, van de Werve G. Neuro-endocrine disorders seen as triggers of the triad: obesity--insulin resistance--abnormal glucose tolerance. DIABETES/METABOLISM REVIEWS 1985; 1:261-91. [PMID: 3915255 DOI: 10.1002/dmr.5610010303] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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38
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Marshall JB, Kapcala LP, Manning LD, McCullough AJ. Effect of corticotropin-like intermediate lobe peptide on pancreatic exocrine function in isolated rat pancreatic lobules. J Clin Invest 1984; 74:1886-9. [PMID: 6209301 PMCID: PMC425369 DOI: 10.1172/jci111608] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Naturally occurring derivatives of pro-opiomelanocortin (POMC) have been identified in various extra-pituitary sites, including the endocrine and exocrine pancreas. Corticotropin-like intermediate lobe peptide (CLIP = ACTH18-39), a naturally occurring derivative of POMC, has been suggested to be an insulin secretagogue. To determine whether CLIP might also affect the exocrine pancreas, we measured its effect on amylase secretion and protein synthesis and secretion in isolated rat pancreatic lobules. Lobules were dual-pulsed with trace amounts of 14C- and 3H-leucine, both in the presence and absence of CLIP (10(-9)-10(-6) M), using a technique that permitted the labeling of both the synthetic and secretory compartments. The effect of CLIP on protein synthesis was determined by comparing 3H-leucine incorporation into lobules with and without CLIP. The secretory effect of CLIP was determined by measuring (a) secreted 14C-labeled protein as a percent of total incorporated radiolabeled protein, and (b) amylase release into incubation medium. The effect of CLIP on amylase release was compared with that of secretin, cholecystokinin-octapeptide, and carbamylcholine. To localize the biologically active region of CLIP, we similarly studied synthetic ACTH25-39. We demonstrated that CLIP stimulates amylase and protein secretion in a dose-dependent manner and is of similar potency to secretin and carbamylcholine. This effect appears to require the ACTH18-24 region of CLIP and results from stimulus-secretion coupling rather than augmented protein synthesis. We also confirmed the presence of immunoreactive-adrenocorticotropic hormone (IR-ACTH) in rat pancreatic extract using a COOH-terminally directed antibody to ACTH1-39 and demonstrated that this IR-ACTH co-eluted with synthetic CLIP. These findings suggest that CLIP might be an endogenous modulator of pancreatic exocrine function.
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39
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Knip M, Lautala P, Akerblom HK, Kouvalainen K, Martin JM. Partial purification of an insulin-releasing activity in human serum. Life Sci 1983; 33:2311-9. [PMID: 6358757 DOI: 10.1016/0024-3205(83)90265-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
An activity that enhances insulin release from perifused rat pancreatic islets has recently been isolated from human serum fractions (molecular weight 1,000-5,000 daltons). To characterize this activity we have studied the insulin-releasing effect of serum subfractions from obese and non-obese children obtained by reversed-phase high-performance liquid chromatography (HPLC). The serum insulin-releasing activity eluted in the HPLC system at 12-13 minutes, which corresponded to the retention time of the tridecapeptide insulin-glucagon liberin isolated from bovine hypothalamus. Insulin-releasing activity was found in serum subfractions from both obese and normal-weight children. The relative insulin-releasing potency of the active subfractions was higher than that of the original total serum fractions, indicating the presence of some substance(s) which inhibit insulin secretion in the total serum fractions. Oral glucose loading increased the relative insulin-releasing activity in the HPLC subfractions from obese children. This study suggests that the insulin secretagogue in human serum might be identical to hypothalamic insulin-glucagon liberin as these substances behave similarly on reversed-phase HPLC and have parallel insulin-releasing properties.
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41
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Humphries J, Nurse EF, Dunmore SJ, Beloff-Chain A, Taylor GW, Morris HR. Beta-cell tropin: synthesis and biological activity. Biochem Biophys Res Commun 1983; 114:763-6. [PMID: 6349635 DOI: 10.1016/0006-291x(83)90846-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The structure of beta-cell tropin, an insulin secretagogue released by the neuro-intermediate lobe of the obese (ob/ob) mouse, has recently been determined as the 22-39 moiety of ACTH. A method for the preparation of this octadecapeptide using mild solid-phase procedures followed by preparative high pressure liquid chromatography is described. The molecular weight of the synthetic peptide has been confirmed by Fast Atom Bombardment mass spectrometry. Synthetic beta-cell tropin is indistinguishable in its chromatographic, antigenic and biological properties from natural beta-cell tropin.
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