W I Sivitz

Summary

Affiliation: University of Iowa
Country: USA

Publications

  1. pmc Bioenergetic effects of mitochondrial-targeted coenzyme Q analogs in endothelial cells
    Brian D Fink
    Departments of Internal Medicine Endocrinology, University of Iowa, Iowa City, Iowa, USA
    J Pharmacol Exp Ther 342:709-19. 2012
  2. ncbi request reprint Lipotoxicity and glucotoxicity in type 2 diabetes. Effects on development and progression
    W I Sivitz
    Department of Internal Medicine, Division of Endocrinology and Metabolism, University of Iowa College of Medicine, Iowa City, USA
    Postgrad Med 109:55-9, 63-4. 2001
  3. ncbi request reprint Understanding insulin resistance. What are the clinical implications?
    William I Sivitz
    Department of Internal Medicine, University of Iowa Roy J and Lucille A Carver College of Medicine, Iowa City 52246, USA
    Postgrad Med 116:41-8. 2004
  4. ncbi request reprint Leptin and body fat in type 2 diabetes and monodrug therapy
    William I Sivitz
    Department of Internal Medicine, Division of Endocrinology, Iowa City Veterans Affairs Medical Center and University of Iowa, Iowa City, Iowa 52246, USA
    J Clin Endocrinol Metab 88:1543-53. 2003
  5. ncbi request reprint Sympathetic inhibition, leptin, and uncoupling protein subtype expression in normal fasting rats
    W I Sivitz
    Department of Internal Medicine, Division of Adult and Pediatric Endocrinology, University of Iowa, Iowa City, Iowa 52246, USA
    Am J Physiol 277:E668-77. 1999
  6. ncbi request reprint Fasting and leptin modulate adipose and muscle uncoupling protein: divergent effects between messenger ribonucleic acid and protein expression
    W I Sivitz
    Department of Internal Medicine, University of Iowa and the Iowa City Veterans Affairs Medical Center, 52246, USA
    Endocrinology 140:1511-9. 1999
  7. ncbi request reprint Obesity impairs vascular relaxation in human subjects: hyperglycemia exaggerates adrenergic vasoconstriction arterial dysfunction in obesity and diabetes
    William I Sivitz
    Division of Endocrinology and Metabolism, Department of Internal Medicine, Iowa City Veterans Affairs Medical Center and the University of Iowa, Iowa City, IA 52242, USA
    J Diabetes Complications 21:149-57. 2007
  8. pmc Mitochondrial dysfunction in diabetes: from molecular mechanisms to functional significance and therapeutic opportunities
    William I Sivitz
    Department of Internal Medicine, Division of Endocrinology and Metabolism, Iowa City Veterans Affairs Medical Center and University of Iowa, Iowa City, Iowa, USA
    Antioxid Redox Signal 12:537-77. 2010
  9. pmc Mitochondrial superoxide and coenzyme Q in insulin-deficient rats: increased electron leak
    Judith A Herlein
    Department of Internal Medicine Endocrinology, University of Iowa and Iowa City Veterans Affairs Medical Center, Iowa City, Iowa, USA
    Am J Physiol Regul Integr Comp Physiol 301:R1616-24. 2011
  10. ncbi request reprint Effects of leptin on insulin sensitivity in normal rats
    W I Sivitz
    Department of Internal Medicine, University of Iowa and the Iowa City Veterans Affairs Medical Center, 52246, USA
    Endocrinology 138:3395-401. 1997

Research Grants

Collaborators

Detail Information

Publications39

  1. pmc Bioenergetic effects of mitochondrial-targeted coenzyme Q analogs in endothelial cells
    Brian D Fink
    Departments of Internal Medicine Endocrinology, University of Iowa, Iowa City, Iowa, USA
    J Pharmacol Exp Ther 342:709-19. 2012
    ..These bioenergetic and redox actions need to be considered as these compounds are developed for therapeutic purposes...
  2. ncbi request reprint Lipotoxicity and glucotoxicity in type 2 diabetes. Effects on development and progression
    W I Sivitz
    Department of Internal Medicine, Division of Endocrinology and Metabolism, University of Iowa College of Medicine, Iowa City, USA
    Postgrad Med 109:55-9, 63-4. 2001
    ..Lifestyle modifications and certain new pharmacologic agents may be effective in modulating these effects and could prove useful in primary prevention of type 2 diabetes...
  3. ncbi request reprint Understanding insulin resistance. What are the clinical implications?
    William I Sivitz
    Department of Internal Medicine, University of Iowa Roy J and Lucille A Carver College of Medicine, Iowa City 52246, USA
    Postgrad Med 116:41-8. 2004
    ....
  4. ncbi request reprint Leptin and body fat in type 2 diabetes and monodrug therapy
    William I Sivitz
    Department of Internal Medicine, Division of Endocrinology, Iowa City Veterans Affairs Medical Center and University of Iowa, Iowa City, Iowa 52246, USA
    J Clin Endocrinol Metab 88:1543-53. 2003
    ..Our data suggest that plasma leptin is reduced in untreated type 2 diabetes probably as a consequence of reduced insulin secretion and that circulating leptin concentrations are differentially affected by monodrug therapy...
  5. ncbi request reprint Sympathetic inhibition, leptin, and uncoupling protein subtype expression in normal fasting rats
    W I Sivitz
    Department of Internal Medicine, Division of Adult and Pediatric Endocrinology, University of Iowa, Iowa City, Iowa 52246, USA
    Am J Physiol 277:E668-77. 1999
    ..However, the in vivo modulation of leptin and UCPs appears complex and, beyond a causal effect of SNA per se, may depend on concurrent changes in plasma insulin, glucose, and circulatory hemodynamics...
  6. ncbi request reprint Fasting and leptin modulate adipose and muscle uncoupling protein: divergent effects between messenger ribonucleic acid and protein expression
    W I Sivitz
    Department of Internal Medicine, University of Iowa and the Iowa City Veterans Affairs Medical Center, 52246, USA
    Endocrinology 140:1511-9. 1999
    ..In summary, UCP subtype mRNA and protein are regulated in tissue- and subtype-specific fashion by leptin and food restriction. Under certain conditions, the effects of these perturbations on UCP mRNA and protein are discordant...
  7. ncbi request reprint Obesity impairs vascular relaxation in human subjects: hyperglycemia exaggerates adrenergic vasoconstriction arterial dysfunction in obesity and diabetes
    William I Sivitz
    Division of Endocrinology and Metabolism, Department of Internal Medicine, Iowa City Veterans Affairs Medical Center and the University of Iowa, Iowa City, IA 52242, USA
    J Diabetes Complications 21:149-57. 2007
    ..Arterial dysfunction occurs in obesity and diabetes. However, there is uncertainty about the relative contribution of endothelial dysfunction, smooth muscle dysfunction, or adrenergic hyperresponsiveness...
  8. pmc Mitochondrial dysfunction in diabetes: from molecular mechanisms to functional significance and therapeutic opportunities
    William I Sivitz
    Department of Internal Medicine, Division of Endocrinology and Metabolism, Iowa City Veterans Affairs Medical Center and University of Iowa, Iowa City, Iowa, USA
    Antioxid Redox Signal 12:537-77. 2010
    ..We also address the role of mitochondrial uncoupling and coenzyme Q. Finally, we address the potential for targeting mitochondria in the therapy of diabetes...
  9. pmc Mitochondrial superoxide and coenzyme Q in insulin-deficient rats: increased electron leak
    Judith A Herlein
    Department of Internal Medicine Endocrinology, University of Iowa and Iowa City Veterans Affairs Medical Center, Iowa City, Iowa, USA
    Am J Physiol Regul Integr Comp Physiol 301:R1616-24. 2011
    ..This is evident on multiple energy substrates and in different respiratory states. CoQ is not reduced in diabetic mitochondria or with weight loss due to food restriction. The implications of these findings are discussed...
  10. ncbi request reprint Effects of leptin on insulin sensitivity in normal rats
    W I Sivitz
    Department of Internal Medicine, University of Iowa and the Iowa City Veterans Affairs Medical Center, 52246, USA
    Endocrinology 138:3395-401. 1997
    ..These effects did not appear dependent on altered body weight. Leptin also altered salt and water metabolism under fasting conditions resulting in increased water intake and more dilute urine...
  11. ncbi request reprint Effect of acute and antecedent hypoglycemia on sympathetic neural activity and catecholamine responsiveness in normal rats
    W I Sivitz
    Department of Internal Medicine, University of Iowa and the Iowa City Veterans Affairs Medical Center, USA
    Diabetes 50:1119-25. 2001
    ..Alternatively, it is possible that the decrease in epinephrine responsiveness after antecedent hypoglycemia could be the result of reduced adrenal sympathetic nerve responsiveness...
  12. pmc Receptor-mediated regional sympathetic nerve activation by leptin
    W G Haynes
    Hypertension Genetics Specialized Center of Research, University of Iowa College of Medicine and Veterans Affairs Medical Center, Iowa City, Iowa 52242, USA
    J Clin Invest 100:270-8. 1997
    ..These data demonstrate that leptin increases thermogenic sympathetic nerve activity and reveal an unexpected stimulatory effect of leptin on overall sympathetic nerve traffic...
  13. ncbi request reprint Adiponectin and C-reactive protein in obesity, type 2 diabetes, and monodrug therapy
    Darcy M Putz
    Department of Internal Medicine, Division of Endocrinology, Iowa City Veterans Affairs Medical Center, IA 52246, USA
    Metabolism 53:1454-61. 2004
    ..Our data raise the possibility that gender differences in adiponectin may be lost in diabetes. Finally, pharmacologic treatment of diabetes may modulate CRP independent of adiposity...
  14. ncbi request reprint Leptin acts in the central nervous system to produce dose-dependent changes in arterial pressure
    M L Correia
    Specialized Center of Research in Hypertension Genetics, The Cardiovascular Center and Department of Internal Medicine, The University of Iowa, and Veterans Affairs Medical Center, Iowa City, Iowa 52242, USA
    Hypertension 37:936-42. 2001
    ..Leptin appears to oppose the depressor effect of weight loss...
  15. ncbi request reprint Does leptin stimulate nitric oxide to oppose the effects of sympathetic activation?
    J L Mitchell
    Hypertension Genetics Specialized Center of Research, Cardiovascular Center, Diabetes Endocrine Research Center, University of Iowa College of Medicine, Iowa City, USA
    Hypertension 38:1081-6. 2001
    ..These data support the concept that the chronic hemodynamic actions of leptin are likely to be related to sympathetic activation...
  16. ncbi request reprint Rat adipose ob mRNA levels in states of altered circulating glucose and insulin
    W I Sivitz
    Department of Internal Medicine, University of Iowa School of Medicine, Iowa City 52242, USA
    Biochem Biophys Res Commun 220:520-5. 1996
    ..Six days of insulin administration to normal rats under conditions of ad lib. feeding, but without otherwise preventing the blood glucose from decreasing, resulted in no significant change in levels of either ob or GLUT-4 mRNA...
  17. ncbi request reprint Effects of adenoviral overexpression of uncoupling protein-2 and -3 on mitochondrial respiration in insulinoma cells
    Y Hong
    Department of Internal Medicine, Division of Endocrinology, University of Iowa, Iowa City, Iowa 52246, USA
    Endocrinology 142:249-56. 2001
    ..Our results also suggest an important role for UCP in lipid metabolism and, possibly, insulin secretion...
  18. ncbi request reprint Interactions between the melanocortin system and leptin in control of sympathetic nerve traffic
    W G Haynes
    Hypertension Genetics Specialized Center of Research, Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242, USA
    Hypertension 33:542-7. 1999
    ..Our data also suggest that leptin increases renal SNA through activation of hypothalamic melanocortin receptors. In contrast, sympathoactivation to thermogenic BAT by leptin appears to be independent of the melanocortin system...
  19. ncbi request reprint Role of corticotrophin-releasing factor in effects of leptin on sympathetic nerve activity and arterial pressure
    M L Correia
    Specialized Center of Research in Hypertension Genetics, Department of Internal Medicine, University of Iowa, and Veterans Affairs Medical Center, Iowa City, Iowa 52242, USA
    Hypertension 38:384-8. 2001
    ..These results suggest that corticotrophin-releasing factor may mediate the sympathoexcitatory effect of leptin on thermogenic tissue without altering its cardiovascular actions...
  20. ncbi request reprint Cardiovascular consequences of obesity: role of leptin
    W G Haynes
    Department of Internal Medicine, University of Iowa College of Medicine and Veterans Affairs Medical Center, Iowa City 52242, USA
    Clin Exp Pharmacol Physiol 25:65-9. 1998
    ..Alterations in leptin generation or action may, in part, underlie the sympathetic, endocrine and renal consequences of obesity...
  21. ncbi request reprint Does leptin cause functional peripheral sympatholysis?
    A Jalali
    Department of Internal Medicine, University of Iowa College of Medicine and Veterans Affairs Medical Center, Iowa City 52242, USA
    Am J Hypertens 14:615-8. 2001
    ..Thus, we conclude that leptin does not change regional blood flows, and that leptin also does not appear to have vascular or neural actions to cause peripheral functional sympatholysis...
  22. ncbi request reprint Respiratory uncoupling by UCP1 and UCP2 and superoxide generation in endothelial cell mitochondria
    Brian D Fink
    Department of Internal Medicine, Division of Endocrinology and Metabolism, Iowa City Veterans Affairs Medical Center, University of Iowa, Iowa City, Iowa, USA
    Am J Physiol Endocrinol Metab 288:E71-9. 2005
    ....
  23. ncbi request reprint Sympathetic and cardiorenal actions of leptin
    W G Haynes
    Hypertension Genetics Specialized Center of Research, and Department of Internal Medicine, University of Iowa College of Medicine and Veterans Affairs Medical Center, Iowa City 52242, USA
    Hypertension 30:619-23. 1997
    ..Although we are at an early stage of understanding, we speculate that abnormalities in the actions of leptin may have implications for the sympathetic, cardiovascular, and renal changes associated with obesity...
  24. pmc Endogenous peroxisome proliferator-activated receptor-gamma augments fatty acid uptake in oxidative muscle
    Andrew W Norris
    Department of Pediatrics, University of Iowa, Iowa City, Iowa 52242, USA
    Endocrinology 149:5374-83. 2008
    ..Thus, when PPARgamma activity in muscle is absent or reduced, there will be decreased fatty acid disposal leading to diminished energy utilization and ultimately adiposity...
  25. pmc Superoxide production by mitochondria of insulin-sensitive tissues: mechanistic differences and effect of early diabetes
    Judy A Herlein
    Division of Endocrinology and Metabolism, Department of Internal Medicine, Iowa City Veterans Affairs Medical Center and the University of Iowa, Iowa City, IA 52242, USA
    Metabolism 59:247-57. 2010
    ..However, in any case, excess superoxide production as an intrinsic property of mitochondria of insulin-sensitive tissues does not result from conditions mimicking the pathophysiology of pre- or early diabetes...
  26. pmc Leptin gene -2548G/A variants predict risperidone-associated weight gain in children and adolescents
    Chadi A Calarge
    Department of Psychiatry, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
    Psychiatr Genet 19:320-7. 2009
    ..We aimed to investigate the association between risperidone-induced weight gain, leptin concentration, and the leptin gene (LEP) -2548G/A variants in youths...
  27. ncbi request reprint Leptin administration to normal rats does not alter catecholamine responsiveness to insulin-induced hypoglycemia
    Judith A Herlein
    Department of Internal Medicine, Division of Endocrinology, University of Iowa and the Iowa City Veterans Affairs Medical Center, Iowa City, IA 52246, USA
    Metabolism 52:1484-90. 2003
    ..Moreover, concurrent leptin does not enhance catecholamine responses to insulin in rats exposed to antecedent hypoglycemia...
  28. pmc Mitochondrial targeted coenzyme Q, superoxide, and fuel selectivity in endothelial cells
    Brian D Fink
    Division of Endocrinology and Metabolism, Department of Internal Medicine, Iowa City Veterans Affairs Medical Center and the University of Iowa, Iowa City, Iowa, USA
    PLoS ONE 4:e4250. 2009
    ....
  29. pmc Superoxide and respiratory coupling in mitochondria of insulin-deficient diabetic rats
    Judith A Herlein
    University of Iowa, Iowa City, Iowa 52242, USA
    Endocrinology 150:46-55. 2009
    ....
  30. ncbi request reprint Reactive oxygen and targeted antioxidant administration in endothelial cell mitochondria
    Yunxia O'Malley
    Department of Internal Medicine, Division of Endocrinology and Metabolism, Iowa City Veterans Affairs Medical Center and the University of Iowa, Iowa City, Iowa 52242, USA
    J Biol Chem 281:39766-75. 2006
    ..Mitoquinol blocks ROS from reverse electron transport but increases superoxide production derived from forward transport. These effects likely occur at one or more Q binding sites in complex I...
  31. ncbi request reprint Cyclic changes in glycemia assessed by continuous glucose monitoring system during multiple complete menstrual cycles in women with type 1 diabetes
    Whitney S Goldner
    Division of Endocrinology, Department of Internal Medicine, Roy J and Lucille A Carver College of Medicine, University of Iowa and Veterans Administration Medical Center, Iowa City, Iowa 52246, USA
    Diabetes Technol Ther 6:473-80. 2004
    ..Prolonged use of continuous glucose monitoring was safe in the subjects studied, and is the first method clinically available to monitor glucose control over prolonged periods in individuals with diabetes...
  32. ncbi request reprint Mitochondrial proton leak in obesity-resistant and obesity-prone mice
    Brian D Fink
    University of Iowa, Iowa City Veterans Affairs Medical Center, Iowa City, IA 52242, USA
    Am J Physiol Regul Integr Comp Physiol 293:R1773-80. 2007
    ..But, this is only achieved only at a higher body mass and, therefore, may be adaptive rather than preventative. Neither obesity-prone nor resistant mice respond to HF feeding by expressing more UCP1 in ectopic BAT within muscle tissue...
  33. ncbi request reprint The concept of selective leptin resistance: evidence from agouti yellow obese mice
    Marcelo L G Correia
    Hypertension Genetics Specialized Center of Research and Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, Iowa 52242 1101, USA
    Diabetes 51:439-42. 2002
    ..If leptin resistance is selective in obese humans, then leptin could contribute to sympathetic overactivity and its adverse consequences in human obesity...
  34. ncbi request reprint UCP2-dependent proton leak in isolated mammalian mitochondria
    Brian D Fink
    Department of Internal Medicine, Divisions of Endocrinology and Metabolism, Iowa City Veterans Affairs Medical Center and the University of Iowa, Iowa City, Iowa 55246, USA
    J Biol Chem 277:3918-25. 2002
    ..UCP2-mediated H(+) conduction was not GDP sensitive. These data suggest that the UCP homologue, UCP2, mediates the proton leak in mitochondria of a mammalian cell wherein UCP2 is the native subtype...
  35. ncbi request reprint Hemodynamic consequences of neuropeptide Y-induced obesity
    Marcelo L G Correia
    Specialized Center of Research in Hypertension Genetics, Department of Internal Medicine, University of Iowa, Iowa City 52242, USA
    Am J Hypertens 15:137-42. 2002
    ..Chronic intracerebroventricular (ICV) administration of NPY produces obesity in rats. Obesity has been shown to increase arterial pressure...
  36. ncbi request reprint Free fatty acid-induced beta-cell defects are dependent on uncoupling protein 2 expression
    Jamie W Joseph
    Departments of Medicine and Physiology, University of Toronto, Ontario M5S 1A8, Canada
    J Biol Chem 279:51049-56. 2004
    ..We propose that higher free fatty acid oxidation rates prevent accumulation of triglyceride in UCP2(-/-) islets, such accumulation being a phenomenon associated with lipotoxicity...
  37. ncbi request reprint Differential modulation of leptin-induced sympathoexcitation by baroreflex activation
    Martin Hausberg
    Department of Internal Medicine D, University of Munster, Munster, Germany
    J Hypertens 20:1633-41. 2002
    ..The aim of the present study was to test the hypothesis that the increases in sympathetic nerve activity induced by leptin in different regions respond differentially to baroreflex activation...
  38. ncbi request reprint Uncoupling metabolism and coupling leptin to cardiovascular disease
    Allyn L Mark
    Arterioscler Thromb Vasc Biol 22:881-3. 2002
  39. ncbi request reprint Leptin potentiates thermogenic sympathetic responses to hypothermia: a receptor-mediated effect
    Martin Hausberg
    Department of Internal Medicine D, University of Muenster, Muenster, Germany
    Diabetes 51:2434-40. 2002
    ..The effect depends on intact and functional leptin receptors because it occurs neither in rats with a leptin receptor defect nor in rats with acquired leptin resistance...

Research Grants4

  1. Mitochondrial respiratory uncoupling and the pathogenes*
    William Sivitz; Fiscal Year: 2006
    ..This is mediated by one or more UCP subtype. 4. Altered mitochondrial coupling and consequent changes in mitochondrial ROS formation alter endothelial cell generation of nitric oxide. ..