Stephen E Borst
Affiliation: University of Florida
- Testosterone replacement therapy for older menStephen E Borst
Geriatrics Research, Education, and Clinical Center, North Florida South Georgia Veterans Health System, Gainesville, FL, USA
Clin Interv Aging 2:561-6. 2007..Testosterone therapy produces a number of adverse effects, including worsening of sleep apnea, gynecomastia, polycythemia and elevation of PSA. Efficacy and adverse effects should be assessed frequently throughout the course of therapy...
- Association of resistin with visceral fat and muscle insulin resistanceStephen E Borst
Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611 8206, USA
Cytokine 32:39-44. 2005..Elevation of circulating cytokines may play a role in the development of muscle insulin resistance...
- Orchiectomized Fischer 344 male rat models body composition in hypogonadal stateStephen E Borst
Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
Life Sci 79:411-5. 2006..We conclude that the F344 rat displays a broad range of catabolic effects following ORX and is the best rat model for studying the androgenic pathway and strategies for reversing catabolic changes induced by hypogonadism...
- Interventions for sarcopenia and muscle weakness in older peopleStephen E Borst
VA Medical Center, GRECC 182, 1601 SW Archer Road, Gainesville, FL 32608 1197, USA
Age Ageing 33:548-55. 2004..Those strategies are testosterone replacement for men, growth hormone replacement and resistance exercise training. This review will cover the risks and benefits associated with each of these interventions...
- Inhibition of 5alpha-reductase blocks prostate effects of testosterone without blocking anabolic effectsStephen E Borst
Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
Am J Physiol Endocrinol Metab 288:E222-7. 2005..0001). This study demonstrates that 5alpha-reductase inhibitors may block the undesirable effects of T on the prostate, without blocking the desirable anabolic effects of T on muscle, bone, and fat...
- Neutralization of tumor necrosis factor-alpha reverses insulin resistance in skeletal muscle but not adipose tissueStephen E Borst
Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA
Am J Physiol Endocrinol Metab 287:E934-8. 2004..TNF-alpha neutralization was accompanied by reduced TNF-alpha bioactivity without tissue depletion of TNF-alpha protein...
- Adipose tumor necrosis factor-alpha is reduced during onset of insulin resistance in Sprague-Dawley ratsStephen E Borst
Department of Physiology, Louisiana State University Health Science Center, New Orleans, LA 70112 1394, USA
Cytokine 26:217-22. 2004..Our findings do not support the adipose-endocrine model of TNF-alpha in insulin resistance. Our findings do support a paracrine role for TNF-alpha or for a reduction in endogenous TNF-alpha inhibitors in insulin resistance...
- The role of TNF-alpha in insulin resistanceStephen E Borst
Department of Exercise and Sport Sciences, University of Florida, Malcom Randall VA Medical Center, Gainesville, Florida 32608 1197, USA
Endocrine 23:177-82. 2004..This review will discuss the regulation of insulin responses by TNF-alpha and evidence supporting the hypothesis that over expression of TNF-alpha plays a role in the pathophysiology of insulin resistance...
- Anabolic effects of testosterone are preserved during inhibition of 5alpha-reductaseStephen E Borst
Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Gainesville, Florida 32608 1197, USA
Am J Physiol Endocrinol Metab 293:E507-14. 2007..Our study demonstrates that the effects of testosterone on muscle and bone can be separated from the prostate effects and provides a testable strategy for combating sarcopenia and osteopenia in older hypogonadal men...
- 17β-Hydroxyestra-4,9,11-trien-3-one (Trenbolone) preserves bone mineral density in skeletally mature orchiectomized rats without prostate enlargementSean C McCoy
Geriatric Research, Education and Clinical Center, VA Medical Center, Gainesville, FL 32608, USA
Bone 51:667-73. 2012..These findings indicate that TREN may be an advantageous agent for future clinical trials evaluating agents capable of preventing bone loss resulting from androgen deficiency...
- 17β-Hydroxyestra-4,9,11-trien-3-one (trenbolone) exhibits tissue selective anabolic activity: effects on muscle, bone, adiposity, hemoglobin, and prostateJoshua F Yarrow
VA Medical Center, University of Florida, Gainesville, 32608 1197, USA
Am J Physiol Endocrinol Metab 300:E650-60. 2011..Our findings indicate that TREN has advantages over supraphysiological testosterone and supports the need for future preclinical studies examining the viability of TREN as an option for androgen replacement therapy...
- A rehabilitation exercise program induces severe bone mineral deficits in estrogen-deficient rats after extended disuseJoshua F Yarrow
1VA Medical Center, Gainesville, FL 32607, USA
Menopause 19:1267-76. 2012..The aim of this study was to determine whether estradiol (E2) influences early-phase bone adaptations to reambulation (REAMB) and/or rehabilitation exercises after hindlimb unloading (HLU) of ovariectomized rats...
- Supraphysiological testosterone enanthate administration prevents bone loss and augments bone strength in gonadectomized male and female ratsJoshua F Yarrow
Geriatric Research, Education and Clinical Center, Veterans Administration Medical Center, Gainesville, Florida, USA
Am J Physiol Endocrinol Metab 295:E1213-22. 2008..In conclusion, TE administration appears protective of cancellous bone in male rats and augments cortical bone strength in both sexes...
- Impact of treadmill locomotor training on skeletal muscle IGF1 and myogenic regulatory factors in spinal cord injured ratsMin Liu
Department of Physical Therapy, University of Florida, P O Box 100154, Rm 1142 PHHP Bldg, Gainesville, FL 32610, USA
Eur J Appl Physiol 109:709-20. 2010..Training-induced muscle regeneration and fiber hypertrophy following SCI was associated with an increase in IGF1, an increase in Pax7 positive nuclei, and upregulation of MRFs...
- Musculoskeletal and prostate effects of combined testosterone and finasteride administration in older hypogonadal men: a randomized, controlled trialStephen E Borst
Geriatric Research, Education and Clinical Center, Malcom Randall Veterans Affairs Medical Center, Gainesville, Florida
Am J Physiol Endocrinol Metab 306:E433-42. 2014..These results demonstrate that elevated DHT mediates testosterone-induced prostate enlargement but is not required for benefits in musculoskeletal or adipose tissue. ..
- High-fat diet induces increased tissue expression of TNF-alphaStephen E Borst
Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32608 1197, USA
Life Sci 77:2156-65. 2005..055). TNF-alpha was undetectable in serum. We conclude that muscle over expression of TNF-alpha occurs during the development of diet-induced obesity and may, in part cause insulin resistance by an autocrine mechanism...
- Overexpression of insulin-like growth factor-1 attenuates skeletal muscle damage and accelerates muscle regeneration and functional recovery after disuseFan Ye
Department of Physical Therapy, PO Box 100154, Room 1142, PHHP Building, University of Florida, Gainesville, FL 32610, USA
Exp Physiol 98:1038-52. 2013..05). These findings demonstrate a potential role of IGF-1 in protecting unloaded skeletal muscles from damage and accelerating muscle repair and regeneration...
- Early-phase neuroendocrine responses and strength adaptations following eccentric-enhanced resistance trainingJoshua F Yarrow
Department of Applied Physiology and Kinesiology, Center for Exercise Science, University of Florida, Gainesville, Florida, USA
J Strength Cond Res 22:1205-14. 2008..In conclusion, TRAD training and ECC+ training appear to result in similar muscular strength adaptations and neuroendocrine responses, while postexercise lactate clearance is enhanced following ECC+ training...
- Methods to quantify sex steroid hormones in bone: applications to the study of androgen ablation and administrationJoshua F Yarrow
Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Gainesville, FL 32608 1197, USA
Am J Physiol Endocrinol Metab 299:E841-7. 2010..We report the validation of a novel method for measuring intraskeletal sex hormones. Our findings demonstrate that the intraskeletal sex steroid reservoirs are modifiable and only partially influenced by circulating sex hormones...
- Modulation of GH/IGF-1 axis: potential strategies to counteract sarcopenia in older adultsSilvia Giovannini
Department of Aging and Geriatric Research, University of Florida, Gainesville, USA
Mech Ageing Dev 129:593-601. 2008....
- Metformin restores responses to insulin but not to growth hormone in Sprague-Dawley ratsStephen E Borst
VA Medical Center, Education and Clinical Center, Gainesville, Florida 32608, USA
Biochem Biophys Res Commun 291:722-6. 2002..The latter may, in part, be explained by the failure of metformin to prevent GH-induced elevation of TNF in visceral fat...
- Neutralization of tumor necrosis factor reverses age-induced impairment of insulin responsiveness in skeletal muscle of Sprague-Dawley ratsStephen E Borst
Department of Exercise and Sport Sciences, University of Florida, Veterans Affairs Medical Center, Geriatric Research, Education and Clinical Center, Gainesville, FL, USA
Metabolism 51:1061-4. 2002..Muscle mass and visceral fat mass were unchanged. These data suggest that skeletal muscle pools of TNF may play an important role in the development of insulin resistance...
- Influence of androgens on circulating adiponectin in male and female rodentsJoshua F Yarrow
Malcom Randall Veterans Affairs Medical Center, Gainesville, FL, USA
PLoS ONE 7:e47315. 2012....
- Tissue selectivity and potential clinical applications of trenbolone (17beta-hydroxyestra-4,9,11-trien-3-one): A potent anabolic steroid with reduced androgenic and estrogenic activityJoshua F Yarrow
Geriatric Research, Education and Clinical Center, VA Medical Center, Gainesville, FL 32608, United States
Steroids 75:377-89. 2010....
- Testosterone dose dependently prevents bone and muscle loss in rodents after spinal cord injuryJoshua F Yarrow
1 VA Medical Center, Research Service, VA Medical Center, Gainesville, Florida
J Neurotrauma 31:834-45. 2014..Testosterone-induced prostate enlargement, however, represents a potential barrier to the clinical implementation of high-dose TE as a means of preserving musculoskeletal tissue after SCI...
- Invalidation of a commercially available human 5α-dihydrotestosterone immunoassayJoshua F Yarrow
VA Medical Center, Gainesville, FL 32608, United States Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, United States Electronic address
Steroids 78:1220-5. 2013..The cross-reactivity of testosterone is particularly concerning because testsoterone is present in 100-fold greater concentrations than is DHT within the circulation...
- Growth hormone responses to acute resistance exercise with vascular restriction in young and old menTodd M Manini
University of Florida, Department of Aging and Geriatric Research, Gainesville, USA
Growth Horm IGF Res 22:167-72. 2012..We hypothesized that low-load RE with vascular restriction would attenuate the known age-related reduction in GH response to RE...
- Neuroendocrine responses to an acute bout of eccentric-enhanced resistance exerciseJoshua F Yarrow
University of Florida, Department of Applied Physiology and Kinesiology, Center for Exercise Science, Gainesville, FL 32611 8206, USA
Med Sci Sports Exerc 39:941-7. 2007....
- Training augments resistance exercise induced elevation of circulating brain derived neurotrophic factor (BDNF)Joshua F Yarrow
VA Medical Center GRECC, Gainesville, FL 32608, United States
Neurosci Lett 479:161-5. 2010....
- Late-life enalapril administration induces nitric oxide-dependent and independent metabolic adaptations in the rat skeletal muscleEmanuele Marzetti
Department of Aging and Geriatric Research, Institute on Aging, University of Florida, PO Box 100143, Gainesville, FL 32610 0143, USA
Age (Dordr) 35:1061-75. 2013..Muscle protection by enalapril administered late in life appears to be primarily mediated by mitigation of oxidative stress and pro-inflammatory signaling...
- Intracrine and myotrophic roles of 5α-reductase and androgens: a reviewJoshua F Yarrow
VA Medical Center, Gainesville, FL 32608 1197, USA
Med Sci Sports Exerc 44:818-26. 2012..The intramuscular expression of these enzymes suggests that skeletal muscle is capable of synthesizing bioactive androgens, which could induce myotrophic effects via intracrine action...
- Impact of viral-mediated IGF-I gene transfer on skeletal muscle following cast immobilizationJennifer E Stevens-Lapsley
Dept of Physical Therapy, Univ of Florida, Gainesville, 32610, USA
Am J Physiol Endocrinol Metab 299:E730-40. 2010..Changes in IGFBP-5 mRNA expression during cast immobilization and reambulation paralleled those of IGF-I, whereas IGFBP-3 expression changed inversely to IGFBP-5...
- Clenbuterol induces muscle-specific attenuation of atrophy through effects on the ubiquitin-proteasome pathwayTossaporn Yimlamai
Department of Applied Physiology and Kinesiology, Univ of Florida, Gainesville, FL, USA
J Appl Physiol 99:71-80. 2005....
- Effects of resistance training on insulin-like growth factor and its binding proteins in men and women aged 60 to 85Stephen E Borst
Department of Exercise and Sport Sciences, University of Florida, Gainesville, Florida, USA
J Am Geriatr Soc 50:884-8. 2002..Our goals were to determine whether RT produces a similar effect in the healthy older persons and to determine the effects of low- versus high-intensity RT on hormonal status...
- Growth hormone isoform responses to GABA ingestion at rest and after exerciseMichael E Powers
Division of Athletic Training, Shenendoah University, Winchester, VA 22601, USA
Med Sci Sports Exerc 40:104-10. 2008..Oral administration of the amino acid/inhibitory neurotransmitter gamma aminobutyric acid (GABA) reportedly elevates resting serum growth hormone (GH) concentrations...