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Inácio MD, Rafacho A, de Paula Camaforte NA, Teixeira P, Vareda PMP, Violato NM, Bosqueiro JR. Prevention of Elevation in Plasma Triacylglycerol with High-Dose Bezafibrate Treatment Abolishes Insulin Resistance and Attenuates Glucose Intolerance Induced by Short-Term Treatment with Dexamethasone in Rats. Int J Endocrinol 2018; 2018:3257812. [PMID: 30532777 PMCID: PMC6250034 DOI: 10.1155/2018/3257812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 08/07/2018] [Accepted: 08/27/2018] [Indexed: 12/04/2022] Open
Abstract
OBJECTIVE Fibrates are used as lipid-lowering drugs and are well tolerated as cotreatments when glucose metabolism disturbances are also present. Synthetic glucocorticoids (GCs) are diabetogenic drugs that cause dyslipidemia, dysglycemia, glucose intolerance, and insulin resistance when in excess. Thus, we aimed to describe the potential of bezafibrate in preventing or attenuating the adverse effects of GCs on glucose and lipid homeostasis. METHODS Male Wistar rats were treated with high-dose bezafibrate (300 mg/kg, body mass (b.m.)) daily for 28 consecutive days. In the last five days, the rats were also treated with dexamethasone (1 mg/kg, b.m.). RESULTS Dexamethasone treatment reduced the body mass gain and food intake, and bezafibrate treatment exerted no impact on these parameters. GC treatment caused an augmentation in fasting and fed glycemia, plasma triacylglycerol and nonesterified fatty acids, and insulinemia, and bezafibrate treatment completely prevented the elevation in plasma triacylglycerol and attenuated all other parameters. Insulin resistance and glucose intolerance induced by GC treatment were abolished and attenuated, respectively, by bezafibrate treatment. CONCLUSION High-dose bezafibrate treatment prevents the increase in plasma triacylglycerol and the development of insulin resistance and attenuates glucose intolerance in rats caused by GC treatment, indicating the involvement of dyslipidemia in the GC-induced insulin resistance.
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Affiliation(s)
- Maiara Destro Inácio
- Institute of Biosciences, São Paulo State University–UNESP, Botucatu, SP, Brazil
| | - Alex Rafacho
- Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina–UFSC, Florianópolis, SC, Brazil
| | | | - Poliana Teixeira
- Institute of Biosciences, São Paulo State University–UNESP, Botucatu, SP, Brazil
| | | | | | - José Roberto Bosqueiro
- Department of Physical Education, Faculty of Sciences, São Paulo State University–UNESP, Bauru, SP, Brazil
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Tan B, Li X, Wu G, Kong X, Liu Z, Li T, Yin Y. Dynamic changes in blood flow and oxygen consumption in the portal-drained viscera of growing pigs receiving acute administration of l-arginine. Amino Acids 2012; 43:2481-9. [DOI: 10.1007/s00726-012-1328-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Accepted: 05/15/2012] [Indexed: 12/18/2022]
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Tan B, Li X, Yin Y, Wu Z, Liu C, Tekwe CD, Wu G. Regulatory roles for L-arginine in reducing white adipose tissue. FRONT BIOSCI-LANDMRK 2012; 17:2237-46. [PMID: 22652774 PMCID: PMC3422877 DOI: 10.2741/4047] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
As the nitrogenous precursor of nitric oxide, L-arginine regulates multiple metabolic pathways involved in the metabolism of fatty acids, glucose, amino acids, and proteins through cell signaling and gene expression. Specifically, arginine stimulates lipolysis and the expression of key genes responsible for activation of fatty acid oxidation to CO2 and water. The underlying mechanisms involve increases in the expression of peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1 alpha), mitochondrial biogenesis, and the growth of brown adipose tissue growth. Furthermore, arginine regulates adipocyte-muscle crosstalk and energy partitioning via the secretion of cytokines and hormones. In addition, arginine enhances AMP-activated protein kinase (AMPK) expression and activity, thereby modulating lipid metabolism and energy balance toward the loss of triacylglycerols. Growing evidence shows that dietary supplementation with arginine effectively reduces white adipose tissue in Zucker diabetic fatty rats, diet-induced obese rats, growing-finishing pigs, and obese patients with type II diabetes. Thus, arginine can be used to prevent and treat adiposity and the associated metabolic syndrome.
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Affiliation(s)
- Bi’e Tan
- Research Center of Healthy Breeding of Livestock and Poultry and Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, the Chinese Academy of Sciences, Changsha, Hunan, China 410125
| | - Xinguo Li
- Hunan Institute of Animal Husbandry and Veterinary Medicine, Changsha, Hunan, China 410131
| | - Yulong Yin
- Research Center of Healthy Breeding of Livestock and Poultry and Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, the Chinese Academy of Sciences, Changsha, Hunan, China 410125
| | - Zhenlong Wu
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China 100193
| | - Chuang Liu
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China 100193
| | - Carmen D. Tekwe
- Department of Statistics, Texas A and M University, College Station, TX, USA 77843-3143
| | - Guoyao Wu
- Research Center of Healthy Breeding of Livestock and Poultry and Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, the Chinese Academy of Sciences, Changsha, Hunan, China 410125
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China 100193
- Department of Animal Science, Texas A&M University, College Station, TX, USA 77843-2471
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Gannon MC, Nuttall JA, Nuttall FQ. Oral arginine does not stimulate an increase in insulin concentration but delays glucose disposal. Am J Clin Nutr 2002; 76:1016-22. [PMID: 12399273 DOI: 10.1093/ajcn/76.5.1016] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Ingested protein increases circulating insulin concentrations. Several years ago it was also determined that an intravenously administered mixture of 10 essential amino acids stimulated insulin secretion. Of these, arginine was the most potent. The effect was synergistic with administered glucose. OBJECTIVE Because the amounts of amino acid administered intravenously were very large and because ingested arginine is partially metabolized in the intestinal mucosa, we were interested in determining whether orally administered arginine stimulates a rise in circulating insulin concentration and whether arginine affects the glucose-induced rise in insulin concentration. DESIGN Nine healthy subjects (4 women and 5 men aged 21-52 y) ingested 1 mmol arginine/kg lean body mass, 1 mmol arginine/kg lean body mass + 25 g glucose, 25 g glucose alone, and water only, in random order on separate occasions, at 0800. Blood samples were obtained at baseline and at 10-min intervals over the next 2 h and were assayed for glucose, insulin, glucagon, and amino acid concentrations. The half-time for gastric emptying was determined by scintigraphy. RESULTS Unlike with intravenous administration, ingested arginine did not stimulate a rise in insulin concentration. The glucagon concentration was increased. Arginine attenuated and prolonged the glucose rise when it was ingested with glucose. Gastric emptying time was similar after ingestion of glucose alone or arginine plus glucose. CONCLUSION Arginine, in an amount likely to be ingested in a high-protein meal, does not stimulate insulin secretion but attenuates the increase in glucose when given with glucose.
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Affiliation(s)
- Mary C Gannon
- Metabolic Research Laboratory and the Section of Endocrinology, Metabolism, and Nutrition, Minneapolis Veterans Administration Medical Center, Department of Food Science and Nutrition, University of Minnesota, Minneapolis 55417, USA.
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Sirtori CR, Calabresi L, Werba JP, Franceschini G. Tolerability of fibric acids. Comparative data and biochemical bases. Pharmacol Res 1992; 26:243-60. [PMID: 1437989 DOI: 10.1016/1043-6618(92)90212-t] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Fibric acids are an established class of drugs for the treatment of hyperlipoproteinaemias. Although they have been in use for 30 years or longer, some doubts remain as to their relative tolerability, both as a class and as single agents. Some side effects, e.g. lithogenicity, may be related to their mode of action, while others, e.g. the acute muscular syndrome, may be linked to the spatial conformation of the molecule. These disadvantages should, however, be weighed against the additional, potentially therapeutic properties shown by these compounds. In particular, effects on maturity onset diabetes and hyperuricaemia, as well as a very interesting fibrinolytic potential, have been described for some of them. A painstaking comparative analysis of the major literature data pertaining to the clinical toxicological profile of these agents allow to conclude that, while belonging to a chemical class, fibric acids show dramatic differences from one another, in terms of side effects and of additional pharmacodynamic activities. Moreover, in the case of lithogenicity for example, considerable differences exist between normo- and hyperlipidaemic subjects. Overall, newer molecules of more sophisticated design have a significantly improved tolerability profile vs the old clofibrate.
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Affiliation(s)
- C R Sirtori
- Center E. Grossi Paoletti, University of Milano, Italy
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Riccardi G, Genovese S, Saldalamacchia G, Patti L, Marotta G, Postiglione A, Rivellese A, Capaldo B, Mancini M. Effects of bezafibrate on insulin secretion and peripheral insulin sensitivity in hyperlipidemic patients with and without diabetes. Atherosclerosis 1989; 75:175-81. [PMID: 2653325 DOI: 10.1016/0021-9150(89)90174-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Although it has been reported that bezafibrate influences carbohydrate metabolism, this possibility has never been properly evaluated in a controlled clinical trial. In this study we attempted to evaluate the effects of bezafibrate on plasma lipoproteins, glucose tolerance, insulin secretion and peripheral insulin sensitivity in a group of hypertriglyceridemic patients with and without diabetes. Sixteen hyperlipidemic patients (10 males and 6 females) participated in the study. Eight had type IIB and 8 type IV hyperlipoproteinemia; 6 of them also had non-insulin dependent diabetes mellitus. The study was performed according to a double blind, crossover design: after 1 month wash-out period in which patients were on diet alone, they underwent, in a random order, a period of placebo therapy and another period in which they received a single daily dose of a long-acting bezafibrate preparation (400 mg) administered in the evening. Each treatment lasted 2 months. Total plasma and VLDL triglyceride concentrations were consistently reduced by bezafibrate (-46%, P less than 0.001; and -50%, P less than 0.001). Total and VLDL-cholesterol were also reduced by bezafibrate. The effects of bezafibrate on lipoproteins were similar in diabetic and non-diabetic subjects. Bezafibrate treatment did not influence fasting blood glucose concentration, glucose tolerance, peripheral insulin sensitivity or insulin secretion. In conclusion, the results of this controlled trial clearly indicate that bezafibrate can be successfully employed to lower plasma lipid levels in patients with non-insulin dependent diabetes mellitus and hyperlipidemia.
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Affiliation(s)
- G Riccardi
- Institute of Internal Medicine and Metabolic Diseases, 2nd Medical School, University of Naples, Italy
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Zelewski M, Swierczyński J. The influence of prolonged clofibrate treatment on the plasma drug concentration and liver NADP-linked enzymes activity. GENERAL PHARMACOLOGY 1986; 17:117-9. [PMID: 3949145 DOI: 10.1016/0306-3623(86)90023-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The clofibric acid (CPIB) concentration in the rat blood plasma during 14 days of treatment with clofibrate and after cessation of the treatment, was measured and compared with the changes of some NADP-linked dehydrogenases activity. CPIB rapidly accumulates in the plasma during the first two days of clofibrate administration reaching a maximum concentration of about 0.6 mM. Then a linear decrease of the drug concentration was observed. The second day after clofibrate treatment had been completed, CPIB could no longer be detected in the plasma. Liver malic enzyme activity increased constantly up to the third day after cessation of the treatment. There was a decrease of activity which reached its control level on the 32nd day of the experiment. The variation patterns of hexose monophosphate shunt dehydrogenases activity and liver weight were similar to the changes of malic enzyme activity.
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Noseda G, Fragiacomo C, Gatti E, Descovich G, Sirtori CR. Glucagon release following experimental diets in man: effects of soybean and casein enriched diets. PHARMACOLOGICAL RESEARCH COMMUNICATIONS 1982; 14:867-78. [PMID: 6757973 DOI: 10.1016/s0031-6989(82)80011-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Lithell H, Vessby B, Hellsing K. Changes in glucose tolerance and plasma insulin during lipid-lowering treatment with diet, clofibrate and niceritrol. Atherosclerosis 1982; 43:177-84. [PMID: 7052096 DOI: 10.1016/0021-9150(82)90020-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
In an effort to reduce serum lipids in patients with atherosclerotic manifestations, a combined treatment with a conventional lipid-lowering diet, clofibrate and niceritrol was used. The effect on glucose metabolism of such treatment was studied. Among the 106 patients 66 took the full dose of both drugs and of these 51 were weight-stable and non-diabetic. The effects of the diet and the drugs were evaluated in this subsample. Diet had no effect on fasting blood glucose concentration, the K value of an intravenous glucose tolerance test (IVGTT) and concentrations of serum insulin. Niceritrol treatment was associated with increased blood glucose, decreased K value, elevated fasting serum insulin and serum insulin at 60 min during IVGTT. Clofibrate had the opposite effects to niceritrol and when both drugs were combined, carbohydrate metabolism was unchanged compared with the pre-treatment state.
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Raheja KL, Linscheer WG, Patel DG. Hypolipidemic and glycogenolytic effect of clofibrate (CPIB) in hypothyroid mice: role of insulin and glucagon. GENERAL PHARMACOLOGY 1982; 13:49-52. [PMID: 7037529 DOI: 10.1016/0306-3623(82)90010-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
1. The role of endogenous glucagon and insulin on the hypolipidemic and glycogenolytic effect of clofibrate was determined in the euthyroid and propylthiouracil (PTU)-induced hypothyroid mice. 2. PTU was fed in diet (0.15%) for 2 weeks and then clofibrate added to diet (0.25%) for 4 weeks. 3. Both PTU and clofibrate significantly increased liver weight but had no effect on kidney weight. PTU significantly decreased plasma triglycerides (TG) and increased cholesterol (Ch). 4. Clofibrate had a significant hypotriglyceridemic effect in both euthyroid and hypothyroid mice but did not affect plasma cholesterol. 5. Clofibrate decreased hepatic glycogen in euthyroid but not in hypothyroid mice. 6. Glucose-6-phosphatase activity was not affected by either PTU or clofibrate. 7. Neither PTU nor clofibrate affected hepatic TG or Ch. 8. Biliary lipid changes due to PTU treatment were reversed by clofibrate administration. 9. Since plasma insulin and glucagon levels were not affected by clofibrate in either euthyroid or hypothyroid mice, our results suggest that the hypotriglyceridemic and glycogenolytic effect of clofibrate is not mediated by changes in circulating insulin and glucagon ratio. 10. Moreover, while the glycogenolytic effect of clofibrate seems to be dependent, the hypotriglyceridemic effect seems to be independent of thyroid hormones.
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11
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Raheja KL, Lincheer WG, Cho C. Glycogenolytic and hypolipidemic effect of clofibrate (CPIB) in the hypothyroid chick. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. C: COMPARATIVE PHARMACOLOGY 1980; 66:243-7. [PMID: 6107203 DOI: 10.1016/0306-4492(80)90134-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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12
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Feldman EB, Gluck FB, Carter AC. Effects of halofenate on glucose tolerance in patients with hyperlipoproteinemia. J Clin Pharmacol 1978; 18:241-8. [PMID: 346616 DOI: 10.1002/j.1552-4604.1978.tb02442.x] [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: 12/14/2022]
Abstract
Halofenate, a triglyceride- and uric acid-lowering drug, potentiated the effect of oral hypoglycemics. Its effect on serial glucose tolerance was evaluated in ten patients with hypertriglyceridemia without overt diabetes. Six-hour oral glucose tolerance tests were done during a control period and every 24 weeks over two years of halofenate treatment. Abnormal glucose tolerance (chemical diabetes) was observed during the control period in six of ten patients. The number of abnormal tests gradually decreased to none by 48 weeks. Plasma glucose, insulin, and free fatty acid values during the glucose tolerance tests were reduced significantly. Halofenate induced significant serum uric acid reduction. No significant regressions were observed among levels of lipids, hormones, glucose, and uric acid. The mechanisms by which lipid-lowering drugs improve glucose tolerance are as yet unexplained.
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Lithell H, Boberg J, Hellsing K, Lundqvist G, Vessby B. Increase of the lipoprotein-lipase activity in human skeletal muscle during clofibrate administration. Eur J Clin Invest 1978; 8:67-74. [PMID: 417937 DOI: 10.1111/j.1365-2362.1978.tb00814.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Lipoprotein-lipase activity was determined in tissue from the skeletal muscle of the leg and the subcutaneous adipose tissue of the abdomen in fourteen patients before and after 1 month of clofibrate administration. The concentrations of serum triglycerides decreased by, on the average, 37% in a group of thirteen patients which mainly consisted of subjects with type-IV hyperlipoproteinaemia. Clofibrate administration was associated with an average increase of the skeletal muscle-tissue lipoprotein-lipase activity of 50% (P less than 0.005). There was a significant correlation between the percentage changes in skeletal muscle-tissue lipoprotein-lipase activity and those of the triglycerides concentrations and the K2-values in an intravenous fat tolerance test during clofibrate treatment. Adipose-tissue lipoprotein-lipase activity did not change significantly. One patient with type-I hyperlipoproteinaemia had very low values of skeletal muscle-tissue lipoprotein-lipase activity and moderately low adipose-tissue lipoprotein-lipase activity. In this patient, neither the tissue lipoprotein-lipase activity nor the triglycerides concentration changed during clofibrate therapy. Fasting serum insulin concentrations decreased significantly during clofibrate administration and the percentage decrease was significantly correlated to the percentage increase of skeletal-muscle lipoprotein-lipase activity. It is suggested that the lowering of insulin levels is a possible mechanism through which glucagon activity is enhanced and this may increase skeletal muscle-tissue lipoprotein-lipase activity.
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Schade DS, Eaton RP, George S, Conway M, Kaminsky N, Sivinski J. Metabolic effects of clofibrate in insulin-dependent ketosis-prone diabetic man. Metabolism 1978; 27:461-8. [PMID: 416322 DOI: 10.1016/0026-0495(78)90100-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This study examined the effects of clofibrate therapy on basal plasma substrate and hormone concentrations in ketosis-prone insulin-dependent diabetic man. A double-blind crossover design was utilized during a 3-mo period in which clofibrate treatment (1 g b.i.d.) was compared to that of a lactose placebo (1 g b.i.d.). Our results demonstrate that clofibrate treatment resulted in a significant reduction in the concentration of plasma glucose, ketone bodies, free fatty acids, triglyceride, and cholesterol in diabetic man. These beneficial effects were observed without demonstrable changes in circulating concentrations of insulin and glucagon. These observations suggest that in ketosis-prone diabetic man, clofibrate therapy may provide an adjunct to exogenous insulin administration.
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Lithell H, Boberg J, Hedstrand H, Hellsing K, Ljunghall S, Vessby B. Effects of clofibrate on glucose tolerance, serum insulin, serum lipoproteins and plasma fibrinogen. Eur J Clin Pharmacol 1977; 12:51-7. [PMID: 332503 DOI: 10.1007/bf00561405] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Greten H, Laible V, Zipperle G, Augustin J. Comparison of assay methods for selective measurement of plasma lipase. The effect of clofibrate on hepatic and lipoprotein lipase in normals and patients with hypertriglyceridemia. Atherosclerosis 1977; 26:563-72. [PMID: 856226 DOI: 10.1016/0021-9150(77)90123-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Three different assays for selective measurement of plasma lipoprotein lipase (LPL) and hepatic triglyceride lipase (H-TGL) were compared. These were: an immunochemical method based on enzyme antibody precipitation (IM), a procedure in which both enzymes were separated by affinity chromatography on small heparin--Sepharose columns (HS), and an assay in which one enzyme was inhibited by protamine sulfate (PS). Good correlations were found between the immunochemical and the heparin--Sepharose method, but not between these and the protamine sulfate assay procedure. The IM was then used to evaluate the effect of clofibrate on the two lipolytic enzymes. It was found that both in normals and in patients with Type IV hyperlipoproteinemia, clofibrate treatment leads to a specific increase of plasma LPL while H-TGL activity remains almost unaffected. The magnitude of the LPL response was different in normals and in patients with endogenous hyperlipoproteinemia. Furthermore, in normals the maximal increase of LPL activity was already reached one week after drug treatment was begun, while in hypertriglyceridemic patients, this effect was not evident prior to four weeks of clofibrate treatment. The marked enzyme increase following clofibrate administration indicates that an increased peripheral removal rate for triglycerides is one major mechanism responsible for the lipid-lowering effect of this drug.
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Ferrari C, Frezzati S, Romussi M, Bertazzoni A, Testori GP, Antonini S, Paracchi A. Effects of short-term clofibrate administration on glucose tolerance and insulin secretion in patients with chemical diabetes or hypertriglyceridemia. Metabolism 1977; 26:129-39. [PMID: 834147 DOI: 10.1016/0026-0495(77)90048-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The effect of 1-wk administration of clofibrate on plasma glucose and insulin (IRI) before and during oral glucose tolerance tests (OGTT), as well as on serum lipids, uric acid, growth hormone (GH), and cortisol, were evaluated in 18 nondiabetic patients with hypertriglyceridemia and in 28 patients with chemical diabetes. Fasting plasma glucose, OGTT-glucose, and IRI areas were significantly decreased in both groups of patients, though the effects on glucose metabolism were much more marked in diabetics; 30-min IRI relative increase was unchanged; fasting plasma IRI was reduced in diabetics only. Glucose utilization during insulin tolerance tests carried out in 6 diabetics was significantly enhanced after treatment. Serum triglycerides (TG) and cholesterol (Chol) were significantly decreased in both groups of patients, as were serum free fatty acids and uric acid in diabetics; plasma GH and cortisol did not change. Significant correlations were found in diabetics between the postclofibrate decrease in OGTT-glucose area and the following: pretreatment values of serum Chol (r + 0.42, p less than 0.05) and of 30-min IRI absolute and relative increase (r + 0.44 and + 0.38, respectively, p less than 0.05); postclofibrate decreases in serum TG (r + 0.40, p less than 0.05), in fasting plasma glucose (r + 0.73, p less than 0.001), and in OGTT-IRI area (r + 0.57, p less than 0.01). These data suggest that the improvement in glucose metabolism observed during short-term clofibrate administration may be due to increased insulin sensitivity.
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Abstract
This paper reviews most of the clinical studies on the mode of action of halofenate, an established hypolipidemichypouricemic agent in man. In yeast cutlures and in isolated rat adipocytes, halofenate was found to inhibit the conversion of pyruvate to acetyl CoA. While pyruvate dehydrogenase was inhibited in vitro, halofenate also inhibited the activety of various other isolated enzymes. In rats maintained on halofenate in the diet (0.02-0.10%) for 2-14 days, there were 20-40% decreases in plasma cholesterol, trigly cerides, phospholipids, and free fatty acids. Inhibition of liver HMG-CoTA reductase does not appear to account for the hypocholesterolemic effect, and activation of mitochondrial alpha-glycerophosphate dehydrogenase does not explain the hypotriglyceridemic action. Kinetic measurements of the serum appearance and disappearance of triglycerides in drug-treated rats suggest that the hypotriglyceridemic activity is due to a net inhibition of hepatic triglyceride synthesis. Reduction of very low density lipoprotein (VLDL) and high density lipoprotein (HDL) levels in rats with sucrose-induced hyperlipidemia and normalization of the altered apolipoprotein profiles are in accord with the effects of halofenate on plasma triglyceride and cholesterol levels. The reduced insulin-to-glucagon ratio observed in Zucker obese hyperlipemic rats is also consistent with halofenat's hypotriglyceridemic activity. Preliminary experiments in rats on the mechanism of its hypoglycemic activity, observed in some diabetic hyperlipidemic patients, indicate that halofenate acts differently than conventional oral hypoglycemic agents. Some, but not all, of the effects of halofenate were observed with clofibrate at two to ten times higher levels.
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Fedele D, Tiengo A, Muggeo M, Nosadini R, Crepaldi G. Effects of clofibrate treatment on arginine-induced insulin secretion in endogenous hypertriglyceridemia. Atherosclerosis 1976; 25:191-8. [PMID: 1008908 DOI: 10.1016/0021-9150(76)90025-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Arginine-induced insulin secretion was evaluated in 13 patients with endogenous hypertriglyceridemia (Fredrickson's Type IV) before and after a two-month period of Clofibrate therapy. Clofibrate reduced triglyceride, cholesterol and FFA levels by 68, 28 and 15% respectively and provoked a significant reduction in arginine-induced insulin secretion without modifying glucose response. Arginine-induced insulin secretion was also studied in 11 normal subjects during saline and intralipid infusions. Glucose and insulin basal values, and glucose and insulin response to arginine infusion were not influenced by Intralipid infusion in these controls. These results confirm that clofibrate reduces insulin secretion thereby contributing to decreased serum triglyceride levels.
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Pontiroli AE, Viberti G, Pozza G. Inhibitory effect of clofibrate on arginine-induced insulin secretion in chemical diabetes. ACTA DIABETOLOGICA LATINA 1976; 13:107-10. [PMID: 1020607 DOI: 10.1007/bf02581254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Clofibrate 3 g/die for 10 consecutive days, significantly reduced arginine-induced IRI release in chemical diabetics and in normal controls, whether of normal body weight or obese. Blood glucose levels were not affected by clofibrate. In agreement with previous findings, it would appear that clofibrate, administered for short periods does not lead to a decrease in glucose tolerance. However, studies relating to the effect of chronic clofibrate administration in chemical diabetes are needed in order to be sure that prolonged inhibition of IRI secretion does not lead to overt diabetes.
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Powanda MC, Henriksen EL, Ayala E, Canonico PG. Clofibrate-induced alterations in serum protein patterns. Biochem Pharmacol 1976; 25:785-8. [PMID: 938580 DOI: 10.1016/0006-2952(76)90147-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Eaton RP, Oase R, Schade DS. Altered insulin and glucagon secretion in treated genetic hyperlipemia: a mechanism of theraphy? Metabolism 1976; 25:245-9. [PMID: 1250161 DOI: 10.1016/0026-0495(76)90082-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The influence of Halofenate therapy on insulin and glucagon secretion was examined in the Zucker rat with genetic endogenous hyperlipemia. Coincident with the lipid lowering effects of Halofenate, the net change in the basal bihormonal axis favored glucagon, with the I/G molar ratio (Insulin/Glucagon) decreasing from 2.72 +/- 0.53 to 0.96 +/- 0.20 during treatment with this drug. Following arginine stimulation the I/G ratio remained reduced at 0.87 +/- 0.13 in Halofenate treated animals, contrasting with the statistically greater ratio of 2.5 +/- 0.55 in control animals. The Halofenate induced state of reduced insulin:glucagon was associated with hypolipemia, postarginine hyperglycemia, and hyperketonemia,-three metabolic parameters characteristic of glucagon excess relative to insulin. It is suggested that the lipid-lowering action of Halofenate in genetic hyperlipemia may reflect the altered bihormonal axis induced by the drug.
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Abstract
The most frequent indication for treatment of hyperlipidemia is for prevention of arteriosclerosis, a suspected but unproved benefit. The cornerstone of treatment of primary hyperlipidemia is diet; drugs may be added to, but do not replace, diet. When a drug is used with any patient, its potential benefits and hazards must be carefully weighed for the given subject. The subjects should be carefully followed and observed for side effects. Plasma lipids should be monitored during the course of treatment. Five drugs have been approved by the U.S. Food and Drug Administration for the treatment of hyperlipidemia: cholestyramine, clofibrate, nicotinic acid, sodium dextrothyroxine and beta-sitosterol. The use, the actions and the side effects of each and of several nonapproved agents are discussed.
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Beck P, Arnett DM, Alsever RN, Eaton RP. Effect of contraceptive steroids on arginine- stimulated glucagon and insulin secretion in women. II. Carbohydrate and lipid physiology in insulin-dependent diabetics. Metabolism 1976; 25:23-31. [PMID: 1246206 DOI: 10.1016/0026-0495(76)90156-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The effect of contraceptive steroids on aminogenic glucagon secretion was studied in six insulin-dependent diabetic women. After 2 wk treatment with combined mestranol (80 mug) plus norethindrone (1 mg) daily, the mean peak plasma glucagon response to arginine infusion was suppressed to one-fourth of control levels. This was associated with a small but significant decrease in mean basal plasma cholesterol concentrations. There were no changes in basal plasma triglyceride, free fatty acid, glucose, insulin, or alpha-amino nitrogen concentrations or in daily insulin requirements during mestranol plus norethindrone treatment. These results confirm previous reports of no consistent changes in the insulin requirements of insulin-dependent diabetic women using contraceptive steroids and suggest that these women may not experience dramatic changes in their lipid metabolism during contraceptive therapy.
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Beck P, Eaton RP, Arnett DM, Alsever RN. Effect of contraceptive steroids on arginine-stimulated glucagon and insulin secretion in women: I-Lipid physiology. Metabolism 1975; 24:1055-65. [PMID: 1152675 DOI: 10.1016/0026-0495(75)90099-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
To evaluate the effect of contraceptive steroids on endogenous glucagon and insulin secretion, theta-arginine was infused intravenously in normal young women before and during selective steroid treatment. The effect of the combination of an estrogen derivative (mestranol), plus norethindrone (Norinyl, Syntex) was compared to the effect of ethinyl estradiol alone and to norethindrone alone. All three steroid schedules resulted in suppression of aminogenic insulin secretion. However, glucagon secretion was reduced only with ethinyl estradiol alone or the combination of mestranol plus norethindrone. In accordance with previous reports, treatment with an ethinyl estradiol derivative alone or in combination with norethindrone resulted in a tendency for elevated serum lipid concentration, while norethindrone alone resulted in a significant reduction in serum lipid concentration. These observations suggest an inverse relationship between aminogenic glucagon secretion and serum lipid concentration as influenced by contraceptive steroids. It is suggested that the metabolic effects of these steroids may be mediated in part by the associated alterations in pancreatic hormone secretory capacity.
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Tiengo A, Muggeo M, Assan R, Fedele D, Crepaldi G. Glucagon secretion in primary endogenous hypertriglyceridemia before and after clofibrate treatment. Metabolism 1975; 24:901-14. [PMID: 1143089 DOI: 10.1016/0026-0495(75)90081-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Arginine-induced insulin and glucagon secretion preceding and following clofibrate treatment was studied in 13 patients with endogenous hypertriglyceridemia. A positive correlation was demonstrated between fasting insulin and triglyceride levels and between the fasting insulin/glucagon molar ratio and triglyceride levels. In patients with endogenous hypertriglyceridemia, anginine infusion induced a significantly increased glucagon response with respect to that found in controls. No correlation was found to exist between glucagon and free fatty acids (FFA) or between glucagon and triglyceride levels. The same lack of correlation was found in normal subjects rendered hypertriglyceridemic by means of Intralipid infusion, which did not modify the fasting glucagon-like immunoreactivity (GLI) or the GLI response to arginine. Clofibrate treatment induces a triglyceride reduction (incrementTG) which is correlated with the reduction in the insulin/glucagon molar ration (incrementI/G). After clofibrate treatment there is also a significant reduction in fasting GLI levels and in the insulin response to arginine, and an increase in the glucagon response. Clofibrate could exercise its hypolipidemic effect by modifying the relationship between insulin and glucagon levels.
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Augusti KT, Benaim ME. Effect of essential oil of onion (allyl propyl disulphide) on blood glucose, free fatty acid and insulin levels of normal subjects. Clin Chim Acta 1975; 60:121-3. [PMID: 1126028 DOI: 10.1016/0009-8981(75)90190-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The administration of allyl propyl disulphide (APDS), a volatile substance contained in onion, to six normal volunteers after a 12 hour fast caused a significant fall in the blood glucose levels and a significant rise in the serum insulin levels during the subsequent 4 hours. It is argued that this effect is due to an insulin sparing action. The expected rise of serum free fatty acid levels after fasting did not occur after APDS administration and this effect is probably related to the simultaneous rise in the insulin levels.
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Sirtori CR, Torreggiani D, Fumagalli R. Mechanism of action of hypolipidemic drugs. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1975; 63:123-33. [PMID: 1106138 DOI: 10.1007/978-1-4684-3258-9_8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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