Joshua F. Yarrow

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Brain derived neurotrophic factor (BDNF) is postulated to be an important mediator of exercise-induced neuroprotection. We tested the hypothesis that resistance exercise elevates circulating BDNF. Twenty healthy untrained college-aged males underwent a 5-week traditional or eccentric-enhanced progressive resistance training intervention. Blood was acquired(More)
Testosterone acts directly at androgen receptors and also exerts potent actions following 5α-reduction to dihydrotestosterone (DHT). Finasteride (type II 5α-reductase inhibitor) lowers DHT and is used to treat benign prostatic hyperplasia. However, it is unknown whether elevated DHT mediates either beneficial musculoskeletal effects or prostate enlargement(More)
We tested the hypothesis that chronic testosterone treatment would promote a cardioprotective phenotype against ischemia/reperfusion (I/R) injury. For this study, 3-month-old F344 male rats underwent sham-surgery, orchiectomy (ORX), or ORX plus 21 days testosterone treatment (1.0 mg testosterone/day). At sacrifice, cardiac performance was assessed in a(More)
BACKGROUND Potential cardiovascular (CV) risks of testosterone replacement therapy (TRT) are currently a topic of intense interest. However, no studies have addressed CV risk as a function of the route of administration of TRT. METHODS Two meta-analyses were conducted, one of CV adverse events (AEs) in 35 randomized controlled trials (RCTs) of TRT lasting(More)
PURPOSE The purpose of this study was to compare the total testosterone (TT), bioavailable testosterone (BT), growth hormone (GH), lactate, and ratings of perceived exertion (RPE) responses between a single bout of traditional (TRAD) and eccentric-enhanced resistance exercise (ECC+) of matched training volumes. METHODS Twenty-two previously untrained(More)
Serum concentrations of neuroactive androgens decline in older men and, in some studies, low testosterone is associated with decreased cognitive function and incidence of depression. Existing studies evaluating the effect of testosterone administration on cognition in older men have been largely inconclusive, with some studies reporting minor to moderate(More)
Recently, the development of selective androgen receptor modulators (SARMs) has been suggested as a means of combating the deleterious catabolic effects of hypogonadism, especially in skeletal muscle and bone, without inducing the undesirable androgenic effects (e.g., prostate enlargement and polycythemia) associated with testosterone administration.(More)
High-dose testosterone enanthate (TE) may prevent hypogonadism-induced osteopenia. For this study, 3-mo-old male and female Fisher SAS rats underwent sham surgery, gonadectomy (GX), or GX plus 28 days TE administration (7.0 mg/wk). GX reduced serum sex hormones (i.e., testosterone, dihydrotestosterone, and estradiol) (P < 0.05) in both sexes and bone(More)
Testosterone (T) stimulates erythropoiesis and regulates iron homeostasis. However, it remains unknown whether the (type II) 5α-reduction of T to dihydrotestosterone (DHT) mediates these androgenic effects, as it does in some other tissues. Our purpose was to determine whether inhibition of type II 5α-reductase (via finasteride) alters red blood cell (RBC)(More)
Selective androgen receptor modulators (SARMs) now under development can protect against muscle and bone loss without causing prostate growth or polycythemia. 17β-Hydroxyestra-4,9,11-trien-3-one (trenbolone), a potent testosterone analog, may have SARM-like actions because, unlike testosterone, trenbolone does not undergo tissue-specific 5α-reduction to(More)