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Koşar Can Ö, Cabuş Ü, Kabukcu C, Fenkci S, Fenkci V, Enli Y, Korkmaz B. Changes in serum levels of calcitonin gene-related peptide, adiponectin, and ghrelin in pregnant women with gestational diabetes mellitus. J Obstet Gynaecol Res 2021; 47:4171-4179. [PMID: 34492741 DOI: 10.1111/jog.15016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 07/28/2021] [Accepted: 08/28/2021] [Indexed: 12/01/2022]
Abstract
AIM This study was designed to determine serum calcitonin gene-related peptide (CGRP) levels and define whether serum CGRP concentration is associated with adiponectin and ghrelin in pregnant women with gestational diabetes mellitus (GDM). STUDY DESIGN Thirty-six pregnant women with GDM and 43 normal pregnant women without glucose intolerance were evaluated in this study. The serum concentration of CGRP, adiponectin, and ghrelin were measured in two groups at the last trimester of gestation. MAIN FINDINGS The serum CGRP level in the GDM group was significantly higher than the control group. Serum levels of adiponectin and ghrelin in the GDM group were significantly lower than in the control group. In pregnant women with GDM, there was a significant negative correlation between serum CGRP level and adiponectin level. However, the correlation between maternal serum CGRP levels and ghrelin levels was not significant. CONCLUSION Our investigation shows that serum CGRP level was significantly higher in pregnant women with GDM in comparison with the control group. These results suggest that CGRP may play a very important role in GDM pathogenesis.
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Affiliation(s)
- Özlem Koşar Can
- Department of Obstetrics and Gynecology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Ümit Cabuş
- Department of Obstetrics and Gynecology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Cihan Kabukcu
- Department of Obstetrics and Gynecology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Semin Fenkci
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Veysel Fenkci
- Department of Obstetrics and Gynecology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Yasar Enli
- Department of Biochemistry, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Berker Korkmaz
- Department of Biochemistry, Faculty of Medicine, Pamukkale University, Denizli, Turkey
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Tripathi AS, Wadhwani PJ, Majumder PM, Chandewar AV, Marathe S, Mahajan PG. Amylin dual action: a second gluco regulatory β-cell hormone, treatment and cause for the diabetes. Int J Diabetes Dev Ctries 2014. [DOI: 10.1007/s13410-014-0203-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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3
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Fenkci SM, Fenkci V, Oztekin O, Rota S. Serum calcitonin gene-related peptide levels in women with polycystic ovary syndrome. Arch Gynecol Obstet 2012; 287:1235-9. [PMID: 23263174 DOI: 10.1007/s00404-012-2689-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 12/11/2012] [Indexed: 11/26/2022]
Abstract
PURPOSE Calcitonin gene-related peptide (CGRP) is an amino acid neuropeptide with widespread expression. It has potent effects on lipid and energy metabolism. It induces insulin resistance. This study was planned to determine CGRP levels in women with polycystic ovary syndrome (PCOS). METHODS Forty-seven women with PCOS and 34 healthy controls were evaluated in this controlled clinical study. Serum lipid sub-fractions, postprandial and fasting glucose, insulin and other hormones (gonadotropins, androgens) and CGRP levels were measured. Homeostasis model assessment (HOMA-IR) was used to estimate insulin resistance. RESULTS Waist measurements, postprandial and fasting glucose and fasting insulin levels and free androgen index and HOMA-IR were significantly higher in subjects with PCOS. However, the women with PCOS had considerably lower high-density lipoprotein cholesterol levels than healthy subjects. Serum CGRP levels were higher in study subjects than in controls, although it was statistically insignificant. CONCLUSIONS Serum CGRP level was not related with insulin resistance, ovarian hyperandrogenism and dyslipidemia in abdominally obese women with PCOS. These outcomes propose that CGRP may not play a pivotal role in the pathogenesis of PCOS.
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Affiliation(s)
- Semin Melahat Fenkci
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Cerrahi Hospital, Denizli, Turkey.
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4
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RA Beeley N, Prickett KS. Section Review Oncologic, Endocrine & Metabolic: The amylin, CGRP and calcitonin family of peptides. Expert Opin Ther Pat 2008. [DOI: 10.1517/13543776.6.6.555] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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5
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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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6
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Stoyanova II, Gulubova MV. Immunocytochemical study on the liver innervation in patients with cirrhosis. Acta Histochem 2000; 102:391-402. [PMID: 11145532 DOI: 10.1078/0065-1281-00568] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In the liver, the autonomic nervous system plays an important role in degenerative and inflammatory changes. The aim of the present study was to investigate the distribution of neuronal fibres containing neuropeptides in livers of 5 patients with cirrhosis by immunocytochemical localization at the light and electron microscopical level of substance P (SP), neuropeptide Y (NPY), somatostatin (SOM), and calcitonin gene-related peptide (CGRP). In patients with alcoholic cirrhosis, a decreased number of neuronal fibres was found in the portal tract and fibrous septa as well as in the sinusoids of regenerative nodules. NPY- and SP-immunoreactive neuronal fibres were more numerous than CGRP-containing fibres. They were located mainly in portal tracts. These findings led to the conclusion that peptidergic innervation plays a role in inflammatory and fibrotic changes in cirrhotic liver.
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Affiliation(s)
- I I Stoyanova
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, Thracian University, Stara Zagora, Bulgaria.
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7
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Pittner RA. Lack of effect of calcitonin gene-related peptide and amylin on major markers of glucose metabolism in hepatocytes. Eur J Pharmacol 1997; 325:189-97. [PMID: 9163566 DOI: 10.1016/s0014-2999(97)00132-5] [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: 02/04/2023]
Abstract
Effects of amylin and calcitonin gene-related peptide on several processes involved in carbohydrate metabolism were investigated in rat hepatocytes, non-parenchymal cells (Kupffer, Ito and endothelial cells) and alveolar macrophages. In hepatocytes, cAMP levels were increased 25-fold by glucagon (10 nM), less than 2-fold by calcitonin gene-related peptide (100 nM) and not at all by amylin (100 nM). In non-parenchymal cells and cultured alveolar macrophages, calcitonin gene-related peptide potently, and amylin weakly, stimulated cAMP levels. In hepatocytes neither amylin nor calcitonin gene-related peptide affected glycogen phosphorylase activity, glucose output, lactate uptake, glycogen synthesis, glycogen mass or tyrosine aminotransferase activity. The density of calcitonin gene-related peptide specific binding sites in parenchymal cells was 10-fold less then seen in non-parenchymal cells. We found no significant evidence of specific amylin binding sites. These results are consistent with the notion that amylin does not exert a direct effect in hepatocytes. However, we do not rule out that amylin may affect hepatic glucose output indirectly through Cori cycling of lactate derived from skeletal muscle or from interactions through non-parenchymal cells.
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Affiliation(s)
- R A Pittner
- Amylin Pharmaceuticals, Inc., San Diego, CA 92121-3027, USA.
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8
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Abstract
Amylin, a 37-amino acid peptide, is cosecreted with insulin from the beta-cells of the pancreatic islets in normal response to physiological stimuli. It is the major protein of islet amyloid, which is usually present in the pancreases of people with non-insulin-dependent (type II) diabetes mellitus. Amylin elicits potent effects on carbohydrate metabolism in rodent tissues, causing insulin resistance in skeletal muscle and liver. A close structural relationship exists between amylin and the 2 calcitonin gene-related peptides, which are widely distributed neuropeptides and potent vasodilators. These exert biological effects similar to those of amylin on the organs primarily responsible for the regulation of carbohydrate metabolism. All 3 peptides are thought to cause their biological actions by binding to similar cell surface receptors. This article reviews the field of amylin and its role in the physiological regulation of carbohydrate metabolism, and in disease mechanisms associated with insulin resistance in diabetes mellitus, impaired glucose tolerance and essential hypertension. Potential therapeutic applications are also discussed.
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Affiliation(s)
- G J Cooper
- Developmental Biology and Cancer Research Group, School of Medicine, University of Auckland, New Zealand
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Clementi G, Caruso A, Cutuli VM, de Bernardis E, Prato A, Amico-Roxas M. Amylin given by central or peripheral routes decreases gastric emptying and intestinal transit in the rat. EXPERIENTIA 1996; 52:677-9. [PMID: 8698109 DOI: 10.1007/bf01925572] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The effect of rat amylin on gastric emptying and intestinal transit in the rat was examined. Amylin administered intracerebroventricularly (1, 2, 2.5 or 4 micrograms/rat) produced the maximal decrease in gastric emptying and intestinal transit at the dose of 2.5 micrograms/rat. Higher doses produced a lower effect. Peripheral administration (25, 50 or 100 micrograms/kg) produced dose-dependent effects. Pre-treatment with neostigmine blocked the effect of amylin when it was centrally injected, while the effect of amylin given peripherally was partially reduced. Pre-treatment with domperidone decreased the inhibitory effect of peripherally injected amylin, but no effect was observed when the peptide was centrally injected.
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Affiliation(s)
- G Clementi
- Institute of Pharmacology, University of Catania, School of Medicine, Italy
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Wagner U, Bredenbröker D, Barth PJ, Fehmann HC, von Wichert P. Amylin immunoreactivity in the rat trachea and characterization of the interaction of amylin and somatostatin on airway mucus secretion. RESEARCH IN EXPERIMENTAL MEDICINE. ZEITSCHRIFT FUR DIE GESAMTE EXPERIMENTELLE MEDIZIN EINSCHLIESSLICH EXPERIMENTELLER CHIRURGIE 1995; 195:289-96. [PMID: 8578004 DOI: 10.1007/bf02576799] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Amylin is a peptide containing 37 amino acids that is mainly expressed in pancreatic B-cells and cosecreted with insulin. It is the major component of the islet amyloid typically found in non-insulin-dependent diabetes mellitus. The amylin mRNA is present in RNA isolated from lung, and amylin receptors have been detected in lung membranes. Recently, amylin was shown to be a potent stimulator of airway mucus secretion. In this study, we characterized the site of amylin expression in rat trachea using a highly specific antiserum and the functional interaction of amylin with somatostatin-14 in mucus secreting cells. Amylin-like immunoreactivity is present in epithelial cells of submucous gland acini. The expression pattern varies, since some acini showed strong staining while others were negative. In addition, some columnar cells of the tracheal lining epithelium are strongly stained. Amylin applied submucosally is a potent stimulator of airway mucus secretion. Somatostatin inhibits this effect. Amylin may influence airway mucus secretion by paracrine and endocrine mechanisms, and our data suggest that amylin and somatostatin belong to the increasing number of peptides that are known to influence airway function.
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Affiliation(s)
- U Wagner
- Department of Internal Medicine, Philipps University of Marburg, Germany
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Guillot E, Coste A, Angel I. Alpha 2-adrenoceptors and the regulation of glucose, insulin and amylin levels in diabetic rats. Life Sci 1995; 57:2081-90. [PMID: 7475961 DOI: 10.1016/0024-3205(95)02201-s] [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: 01/25/2023]
Abstract
The effects of the selective alpha 2-adrenoceptor agonist UK 14.304 on glucose, insulin and amylin levels were examined in neonatal streptozotocin-induced diabetic rats. UK 14.304 (0.03 to 0.3 mg/kg i.p.) induced a dose-dependent reduction of both insulin and amylin levels in normal rats while UK 14.304 at 0.03 mg/kg had already a maximal effect in diabetic rats. Amylin/insulin molar ratios rose after UK 14.304 administration in diabetic rats but remainded constant in normal rats. The alpha 2-adrenoceptor antagonist deriglidole (3 mg/kg i.p.) slightly increased insulin and amylin levels in the two groups of rats but glucose levels were more markedly decreased in diabetic rats. Deriglidole completely antagonized UK 14.304 (0.1 mg/kg i.p.)-induced changes thereby normalizing amylin/insulin molar ratios in diabetic rats. These results suggest that insulin and amylin are both under inhibitory control via alpha 2-adrenoceptor though the responses may be differentially regulated. It is further suggested that diabetes in the neonatal streptozotocin-induced rat model is associated with a hypersensitivity of the pancreas to alpha 2-adrenoceptor stimulation.
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Affiliation(s)
- E Guillot
- Synthélabo Recherche, Department of Internal Medicine, Rueil-Malmaison, France
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Bhogal R, Smith DM, Owji AA, Bloom SR. Binding sites for islet amyloid polypeptide in mammalian lung: species variation and effects on adenylyl cyclase. Can J Physiol Pharmacol 1995; 73:1030-6. [PMID: 8846396 DOI: 10.1139/y95-145] [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
Islet amyloid polypeptide (IAPP) and calcitonin gene related peptide (CGRP) share a 47% sequence homology. IAPP can interact with adenylyl cyclase coupled CGRP receptors. We have examined [125I]IAPP binding in mouse, pig, and guinea pig lung membranes in competition with IAPP, CGRP, and CGRP(8-37). Three types of site were shown by order of potency: (i) mouse, IAPP > CGRP(8-37) >> CGRP; (ii) pig, CGRP > IAPP > CGRP(8-37); and (iii) guinea pig, CGRP = IAPP = CGRP(8-37). Chemical cross-linking of [125I]IAPP and [125I]CGRP binding sites in lung demonstrated that both sites had similar molecular weights in any one species but differed across species, i.e., mouse M(r) = 70,000 and 98,000; pig M(r) = 68,000, 56,000, and 47,000; and guinea pig M(r) = 106,000 and 56,000. Adenylyl cyclase activity was stimulated by forskolin and AlCl3-NaF in rat, mouse, pig, and guinea pig membranes. Only in mouse and pig were CGRP and IAPP able to stimulate adenylyl cyclase activity. In mouse lung CGRP and IAPP stimulated adenylyl cyclase activity with EC50 values of 642 +/- 222 nM (n = 4) and 325 +/- 115 nM (n = 4), respectively. In pig lung membranes EC50 values were 5.7 +/- nM (n = 4) for CGRP and 1230 +/- 1130 nM (n = 4) for IAPP. Thus IAPP either did not stimulate adenylyl cyclase activity in these lung membranes or did so with a low potency.
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Affiliation(s)
- R Bhogal
- Department of Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London, United Kingdom
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Stridsberg M. The use of chromogranin, synaptophysin and islet amyloid polypeptide as markers for neuroendocrine tumours. Ups J Med Sci 1995; 100:169-99. [PMID: 8808182 DOI: 10.3109/03009739509178905] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- M Stridsberg
- Department of Clinical chemistry, University Hospital, Uppsala, Sweden
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14
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Maggi CA. Tachykinins and calcitonin gene-related peptide (CGRP) as co-transmitters released from peripheral endings of sensory nerves. Prog Neurobiol 1995; 45:1-98. [PMID: 7716258 DOI: 10.1016/0301-0082(94)e0017-b] [Citation(s) in RCA: 345] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- C A Maggi
- Department of Pharmacology, A. Menarini Pharmaceuticals, Florence, Italy
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15
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Baqué S, Guinovart JJ, Gómez-Foix AM. Amylin impairment of insulin effects on glycogen synthesis and phosphoenolpyruvate carboxykinase gene expression in rat primary cultured hepatocytes. Biochem J 1994; 304 ( Pt 2):449-53. [PMID: 7998979 PMCID: PMC1137513 DOI: 10.1042/bj3040449] [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: 01/28/2023]
Abstract
The ability of amylin to impair hepatic insulin action is controversial. We have found that the effect of amylin in primary cultured hepatocytes is strongly dependent on the culture conditions. Only in hepatocytes preincubated in the presence of fetal serum did amylin, at concentrations ranging from 1 to 100 nM, reduce insulin-stimulated glycogen synthesis rate and glycogen accumulation without showing direct effects. Neither basal glycogen synthase nor glycogen phosphorylase activity was modified by amylin treatment. Nevertheless, amylin (100 nM) blocked the activation of glycogen synthase by insulin. Amylin also proved capable of opposing the reduction in the expression of the phosphoenolpyruvate carboxykinase (PEPCK) gene induced by insulin, whereas the basal mRNA level of PEPCK was unaffected by amylin treatment. Thus, these results show that, in cultured rat hepatocytes, amylin is indeed able to interfere with insulin regulation of glycogenesis and PEPCK gene expression, favouring the hypothesis that amylin may modulate liver sensitivity to insulin.
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Affiliation(s)
- S Baqué
- Departament de Bioquímica i Fisiologia, Facultat de Química, Universitat de Barcelona, Spain
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16
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Bracq S, Clement B, Pidoux E, Moukhtar MS, Jullienne A. CGRP is expressed in primary cultures of human hepatocytes and in normal liver. FEBS Lett 1994; 351:63-6. [PMID: 8076695 DOI: 10.1016/0014-5793(94)00823-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We recently reported that human liver and primary cultures of hepatocytes express calcitonin. We therefore studied the expression of calcitonin gene related peptide (CGRP), the alternative splicing product of the calcitonin gene, in hepatocytes and liver. We used polymerase chain reaction amplification with specific primers to detect the presence of CGRP I and II messengers and a specific radioimmunoassay to measure the peptide. We report here that CGRP is synthesized by primary cultures of hepatocytes and in liver. As liver also possesses specific receptors for CGRP in non-parenchymal cells, a paracrine system could be involved in liver metabolism.
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Baxter MA, Barnett AH. Does amylin have a pathophysiological endocrine role in diabetes mellitus in man? J Diabetes Complications 1994; 8:63-7. [PMID: 8167390 DOI: 10.1016/1056-8727(94)90014-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- M A Baxter
- St. Peter's Hospital, Chertsey, Surrey, Great Britain
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Houslay MD, Morris NJ, Savage A, Marker A, Bushfield M. Regulation of hepatocyte adenylate cyclase by amylin and CGRP: a single receptor displaying apparent negative cooperatively towards CGRP and simple saturation kinetics for amylin, a requirement for phosphodiesterase inhibition to observe elevated hepatocyte cyclic AMP levels and the phosphorylation of Gi-2. J Cell Biochem 1994; 55 Suppl:66-82. [PMID: 7929619 DOI: 10.1002/jcb.240550008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Challenge of intact hepatocytes with amylin only succeeded in elevating intracellular cyclic AMP levels and activating phosphorylase in the presence of the cAMP phosphodiesterase inhibitor IBMX. Both amylin and CGRP similarly activated adenylate cyclase, around 5-fold, although approximately 400-fold higher levels of amylin were required to elicit half maximal activation. Amylin activated adenylate cyclase though apparently simple Michaelien kinetics whereas CGRP elicited activation by kinetics indicative of apparent negative co-operativity. Use of the antagonist CGPP(8-37) showed that both CGRP and amylin activated hepatocyte adenylate cyclase through a common receptor by a mnemonical mechanism where it was proposed that the receptor co-existed in interconvertible high and low affinity states for CGRP. It is suggested that this model may serve as a paradigm for G-protein linked receptors in general. Amylin failed to both stimulate inositol phospholipid metabolism in hepatocytes and to elicit the desensitization of glucagon-stimulated adenylate cyclase. Amylin did, however, elicit the phosphorylation of the inhibitory guanine nucleotide regulatory protein Gi-2 in hepatocytes and prevented the action of insulin in reducing the level of phosphorylation of this G-protein.
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Affiliation(s)
- M D Houslay
- Department of Biochemistry, University of Glasgow, Scotland
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Pittner RA, Albrandt K, Beaumont K, Gaeta LS, Koda JE, Moore CX, Rittenhouse J, Rink TJ. Molecular physiology of amylin. J Cell Biochem 1994; 55 Suppl:19-28. [PMID: 7929615 DOI: 10.1002/jcb.240550004] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Amylin is a 37-amino acid peptide first isolated, purified, and characterized from the amyloid deposits in the pancrease of type 2 diabetics. It is synthesized and secreted primarily from pancreatic beta cells along with insulin. The ability of amylin to potently reduce insulin-stimulated incorporation of glucose into glycogen in skeletal muscle requires both an intact 2Cys-7Cys disulfide bond and a COOH-terminal amide. Amylin has structural and functional relationships to two other messenger proteins, calcitonin and CGRP. Amylin has relatively potent calcitonin-like activity on bone metabolism and weaker CGRP-like activity on the vasculature. CGRP is a slightly weaker agonist than amylin for metabolic responses. Although rat calcitonins are weak, teleost fish calcitonins are very potent agonists for amylin's metabolic effects. This group of peptides appears to act on a family of related G protein-coupled receptors; several variant calcitonin receptors have recently been cloned and expressed. These receptors appear to be coupled to adenylyl cyclase in many instances; recent evidence supports the view that amylin's effects on skeletal muscle occur, at least in large part, through activation of the cAMP pathway.
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Affiliation(s)
- R A Pittner
- Amylin Pharmaceuticals, Inc., San Diego, California 92121
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Zaidi M, Shankar VS, Huang CL, Pazianas M, Bloom SR. Amylin in bone conservation current evidence and hypothetical Considerations. Trends Endocrinol Metab 1993; 4:255-9. [PMID: 18407165 DOI: 10.1016/1043-2760(93)90095-v] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Amylin, a 37-amino-acid long single-chain polypeptide, is structurally homologous to calcitonin and calcitonin gene-related peptide (CGRP). The peptide is secreted from pancreatic beta cells and is thought to have an anti-insulin action. Here, we review the recently described effects of amylin on calcium homeostasis and discuss its possible role in bone conservation. Amylin is a potent hypocalcemic and antiresorptive peptide. Studies using isolated osteoclasts have revealed that amylin inhibits cell motility (Q effect), without affecting cell spread area or elevating cytosolic [Ca(2+)]. Thus, amylin action is similar to that of calcitonin, but lower in potency. Lower circulating concentrations of amylin in type-1 diabetes may cause the bone loss associated with this condition.
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Affiliation(s)
- M Zaidi
- Bone Research Unit, Division of Biochemical Medicine, St. George's Hospital Medical School, London SW 17 ORE, UK
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Young AA, Cooper GJ, Carlo P, Rink TJ, Wang MW. Response to intravenous injections of amylin and glucagon in fasted, fed, and hypoglycemic rats. THE AMERICAN JOURNAL OF PHYSIOLOGY 1993; 264:E943-50. [PMID: 8333519 DOI: 10.1152/ajpendo.1993.264.6.e943] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The actions of intravenous glucagon and amylin, a newly discovered hyperglycemic pancreatic islet hormone, have been compared in 20-h fasted and fed, lightly anesthetized rats, and in rats made hypoglycemic with an insulin infusion. In fasted animals, amylin (75 nmol/kg) was more effective than glucagon (90 nmol/kg) in increasing plasma glucose (glucose increment 4.55 vs. 1.71 mM, P < 0.001). Amylin elicited a marked increase in plasma lactate, as previously reported, whereas glucagon did not alter plasma lactate. In fed animals, glucagon elicited twice as much increase in plasma glucose as did amylin; amylin again elicited a marked lactate increase that was greater (increment 1.45 vs. 0.97 mM, P < 0.05) and more prolonged than in the fasted state, whereas glucagon was without effect on lactate levels. These findings are consistent with glucagon's known action to promote hyperglycemia from hepatic glycogenolysis and amylin's demonstrated action to promote muscle glycogenolysis and increase lactate supply to the liver. Infusions of sodium lactate that produced plasma lactate increments similar to those evoked by 75 nmol/kg amylin evoked patterns of glucose response in fasted and fed rats similar to those evoked by amylin. Thus increased lactate supply to the liver may account for amylin's hyperglycemic effects. Amylin and glucagon could each restore plasma glucose to control levels in fasted animals made hypoglycemic by insulin infusion (plasma glucose reduced to 3.3 mM). A bolus of 75 nmol/kg amylin was more effective than 180 nmol/kg glucagon, restoring basal glucose levels for > 3 h, whereas glucagon restored it for < 1 h.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- A A Young
- Department of Physiology, Amylin Pharmaceuticals, San Diego, California 92121
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Gómez-Foix A, Coats W, Baqué S, Alam T, Gerard R, Newgard C. Adenovirus-mediated transfer of the muscle glycogen phosphorylase gene into hepatocytes confers altered regulation of glycogen metabolism. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)74015-0] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Sternini C, De Giorgio R, Anderson K, Watt PC, Brunicardi FC, Widdison AL, Wong H, Reber HA, Walsh JH, Go VL. Species differences in the immunoreactive patterns of calcitonin gene-related peptide in the pancreas. Cell Tissue Res 1992; 269:447-58. [PMID: 1423511 DOI: 10.1007/bf00353900] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In the pancreas, calcitonin gene-related peptide (CGRP) immunoreactivity has been described in nerve fibers and in distinct types of islet cells. This unique, apparently species-specific cell-type expression prompted the present investigation to clarify further the pattern of CGRP immunoreactivity in different mammalian species (i.e., different strains of rats, mice, guinea pigs, rabbits, cats, dogs, pigs, and humans) commonly used for functional and anatomical studies of the pancreas by means of immunohistochemistry using three different CGRP antibodies. In each species, CGRP-immunoreactive neurites innervate the exocrine and endocrine compartments, the vasculature, and the intrapancreatic ganglia, where they form dense networks encircling unstained cell bodies. The only exception is the pig pancreas, where the islets appear to be devoid of immunoreactive fibers. The overall density of immunoreactive pancreatic axons in different species is as follows: rat, mouse, and rabbit greater than guinea pig greater than or equal to pig and cat much greater than dog and human. CGRP-immunoreactive endocrine cells appear to be restricted to the rat pancreas, where they form a subpopulation of somatostatin-containing D cells. In contrast, in mouse, guinea pig, cat, dog, and human pancreas, a homogeneous staining of the core of the islets, where insulin-producing B cells are located, was visualized in sections incubated with the rabbit CGRP antiserum at 4 degrees C, but not at 37 degrees C (an incubation temperature that does not affect the islet cell staining in the rat nor the fiber labeling in any species). Furthermore, the staining of islet B cells was not reproducible with all the CGRP antibodies used, all of which comparably stain nerve fibers in each species, and islet D cells in the rat. Immunoreactive islet cells were not visualized in pig and rabbit pancreas. These results are consistent with the hypothesis that the expression of CGRP in nerve fibers is a common feature of mammalian pancreas, whereas its expression in endocrine cells appears to be restricted to the D cells of the rat pancreas.
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Affiliation(s)
- C Sternini
- Center for Ulcer Research and Education, School of Medicine, UCLA
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Sternini C. Enteric and visceral afferent CGRP neurons. Targets of innervation and differential expression patterns. Ann N Y Acad Sci 1992; 657:170-86. [PMID: 1637083 DOI: 10.1111/j.1749-6632.1992.tb22766.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- C Sternini
- Department of Medicine, UCLA School of Medicine
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Nouspikel T, Gjinovci A, Li S, Iynedjian PB. Unimpaired effect of insulin on glucokinase gene expression in hepatocytes challenged with amylin. FEBS Lett 1992; 301:115-8. [PMID: 1451780 DOI: 10.1016/0014-5793(92)80222-3] [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: 12/27/2022]
Abstract
Amylin appears to interfere with the action of insulin in muscle and possibly in liver. We have attempted to detect a direct antagonism between amylin and insulin in cultured rat hepatocytes. The stimulation of glucokinase gene expression was used as a marker of insulin action. Amylin proved ineffective in suppressing subsequent accumulation of glucokinase mRNA in response to maximal or submaximal doses of insulin. When applied to cells already induced by prior incubation with insulin alone, amylin failed to reverse induction, in contrast to the effectiveness of glucagon under the same conditions. Thus, amylin is not a physiological antagonist of insulin in the control of hepatic glucokinase gene expression.
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Affiliation(s)
- T Nouspikel
- Division of Clinical Biochemistry, University of Geneva School of Medicine, Switzerland
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Abstract
Amylin is a 37 amino-acid peptide which is secreted from the pancreatic islets of Langerhans. It has major sequence homology with calcitonin gene related peptide. Amylin can precipitate out in these cells to form amyloid. Amylin is secreted by similar stimuli to those that secrete insulin. Amylin has a number of effects that may counteract the effect of secreted insulin, i.e., decreased second phase insulin secretion, increased hepatic glucose output, and inhibition of insulin effects on skeletal muscle. It must, however, be recognized that in many cases the doses necessary to produce these effects appear to be supraphysiological. The putative role of amylin in the hyperglycemia of aging and Type II diabetes mellitus therefore remains controversial. Amylin has a number of other effects including inhibition of osteoclastic activity, vasodilatation, anorectic effects and enhanced memory retention. This review postulates a role for amylin in the pathogenesis of a number of age-related changes.
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Affiliation(s)
- B J Edwards
- Division of Geriatric Medicine, Saint Louis University, School of Medicine, MO 63104
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Wang MW, Carlo P, Fineman M, Rink TJ, Young AA. Induction of acute hyperglycemia, hyperlactemia and hypocalcemia in fed and fasted BALB/c mice by intravenous amylin injection. Endocr Res 1992; 18:321-32. [PMID: 1473524 DOI: 10.3109/07435809209111040] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Amylin has been reported to influence carbohydrate metabolism in rats, dogs and cats. We report here that intravenous injection of 50 micrograms amylin (640 nmol/kg) induced hyperglycemia, hyperlactemia, and hypocalcemia in both fed and 5-hour fasted mice. Peak glucose and lactate increments occurred within 15 minutes of treatment, followed by a slower decline of plasma calcium levels. To determine dose-response characteristics of these effects, fasted animals were given amylin doses ranging from 0.005 micrograms to 500 micrograms (64 pmol/kg to 6.4 mumol/kg). Median effective doses (ED50) for the hyperglycemic, hyperlactemic, and hypocalcemic effects were 155, 16.9 and 190 nmol/kg, respectively, with maximum increases of 6.27 mM for glucose, 1.85 mM for lactate and maximum decrease of 0.37 mM for calcium. The estimated half-life (t1/2) of exogenous amylin in the circulation was 5.0 minutes in fasted mice. These results indicate that amylin is bioactive in mice. The kinetic data predict that biologically effective doses of exogenous amylin result in plasma concentrations comparable to pathophysiological concentrations of endogenous hormone previously reported.
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Affiliation(s)
- M W Wang
- Department of Physiology, Amylin Pharmaceuticals, Inc., San Diego, California 92121
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Wang MW, Carlo P, Rink TJ, Young AA. Amylin is more potent and more effective than glucagon in raising plasma glucose concentration in fasted, anesthetized rats. Biochem Biophys Res Commun 1991; 181:1288-93. [PMID: 1764079 DOI: 10.1016/0006-291x(91)92078-x] [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: 12/28/2022]
Abstract
Amylin is a 37 amino-acid peptide secreted from the pancreatic beta-cells. It has actions on carbohydrate metabolism in vivo, including elevation of blood glucose. In this study, the hyperglycemic effect of intravenous bolus injections of amylin was compared with similar injections of glucagon in 20-hour fasted rats lightly anesthetized with halothane. Administered doses ranged from 0.01 micrograms to 1000 micrograms (about 7 pmol/kg--750 nmol/kg for amylin and 8 pmol/kg--800 pmol/kg for glucagon). Control animals received an equal volume of saline. A single intravenous injection of amylin or glucagon led to an increase of plasma glucose levels, which peaked approximately at 1 hour after treatment. The calculated ED50 for amylin was 1.48 nmol whereas that for glucagon was 7.46 nmol; the maximum glucose increment was 4.3 mM for amylin, and 2.9 mM for glucagon. These results show that amylin is a more potent and more effective hyperglycemic agent than glucagon under these experimental conditions.
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Affiliation(s)
- M W Wang
- Department of Physiology, Amylin Corporation, San Diego, CA 92121
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Abstract
Intravenous injections of 25.5 nmol rat amylin into fasted anesthetized rats caused a rapid increase in plasma lactate followed by an increase in plasma glucose; there was a transient fall in blood pressure. Subcutaneous injection of 25.5 nmol amylin also caused increases in lactate and glucose but did not change blood pressure. Similar responses were observed during somatostatin infusion and in the absence of changes in catecholamines. These results fit with a scheme in which amylin elicits muscle glycogenolysis, release of lactate, and increased hepatic gluconeogenesis due to increased supply of substrate.
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Affiliation(s)
- A A Young
- Amylin Corporation, Department of Physiology, San Diego, CA 92121
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