The use of androgen supplements is becoming increasingly prevalent in the United States mainly in the general population of middle-aged and elderly men with chronic cardiovascular diseases, such as hypertension and type II diabetes, who receive testosterone supplements to treat osteoporosis, improve libido and feelings of well-being, and to improve sexual performance. Despite the common use of androgens, the long term impact of androgen supplements in healthy individuals, much less in individuals who suffer from chronic cardiovascular-renal diseases (CV-RD), is unknown. Recent studies from our laboratory and others indicate that endogenous androgens contribute to greater renal injury in normotensive and hypertensive male rats. However, there is little information regarding whether androgen supplements exacerbate renal injury and by what mechanisms. The overall hypothesis to be tested in this proposal is that androgen supplements exacerbate renal injury by directly increasing oxidative stress via NADPH oxidase, and hemodynamically by increasing transmission of pressure to the glomerulus. We further hypothesize that androgen supplements indirectly increase ROS by stimulating the RAS. Finally, the hypothesis will be tested that androgen supplements could activate NF-DB in the kidney promoting inflammation. In humans the two leading causes for renal injury are hypertension and type II diabetes. Therefore, studies will be performed in male rat models that mimic men who suffer from CV-RD and are prescribed androgen supplements: men with hypertensive renal injury (rats with reduced renal mass on high salt diet), and men with type II diabetes (Zucker rats), using testosterone, the most commonly prescribed androgen for men. Studies will also be performed in human male mesangial cells.
The specific aims of the proposal are to test the hypotheses that: 1) androgen supplements will exacerbate renal injury in rats with hypertension or type II diabetes;2) androgen supplements will exacerbate renal injury by increasing oxidative stress mediated by NADPH oxidase and that the intrarenal RAS plays a role in mediating androgen supplement-induced oxidative stress;3) androgen supplements will exacerbate renal injury by activating NF-DB leading to increased inflammatory cytokines;4) androgen supplements will exacerbate renal injury by increasing transmission of pressure to the glomerulus.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL069194-08
Application #
7813804
Study Section
Hypertension and Microcirculation Study Section (HM)
Program Officer
Thrasher, Terry N
Project Start
2001-09-30
Project End
2013-03-31
Budget Start
2010-04-01
Budget End
2013-03-31
Support Year
8
Fiscal Year
2010
Total Cost
$333,000
Indirect Cost
Name
University of Mississippi Medical Center
Department
Physiology
Type
Schools of Medicine
DUNS #
928824473
City
Jackson
State
MS
Country
United States
Zip Code
39216
Dalmasso, Carolina; Maranon, Rodrigo; Patil, Chetan et al. (2016) Cardiometabolic Effects of Chronic Hyperandrogenemia in a New Model of Postmenopausal Polycystic Ovary Syndrome. Endocrinology 157:2920-7
Regensteiner, Judith G; Golden, Sherita; Huebschmann, Amy G et al. (2015) Sex Differences in the Cardiovascular Consequences of Diabetes Mellitus: A Scientific Statement From the American Heart Association. Circulation 132:2424-47
Reckelhoff, Jane F (2014) Gender medicine: ""in a perfect world …"". Clin Ther 36:1870-1872
Soljancic, Andrea; Ruiz, Arnaldo Lopez; Chandrashekar, Kiran et al. (2013) Protective role of testosterone in ischemia-reperfusion-induced acute kidney injury. Am J Physiol Regul Integr Comp Physiol 304:R951-8
Maranon, Rodrigo; Reckelhoff, Jane F (2013) Sex and gender differences in control of blood pressure. Clin Sci (Lond) 125:311-8
Li, Jing; LaMarca, Babbette; Reckelhoff, Jane F (2012) A model of preeclampsia in rats: the reduced uterine perfusion pressure (RUPP) model. Am J Physiol Heart Circ Physiol 303:H1-8
Afsar, Baris (2012) Testosterone and blood pressure: is the decreased sodium excretion the missing link? Hypertension 59:e41; author reply e42
Ojeda, Norma B; Hennington, Bettye Sue; Williamson, Danielle T et al. (2012) Oxidative stress contributes to sex differences in blood pressure in adult growth-restricted offspring. Hypertension 60:114-22
Lima, Roberta; Wofford, Marion; Reckelhoff, Jane F (2012) Hypertension in postmenopausal women. Curr Hypertens Rep 14:254-60
Lu, Yan; Fu, Yiling; Ge, Ying et al. (2012) The vasodilatory effect of testosterone on renal afferent arterioles. Gend Med 9:103-11

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