Left ventricular remodeling with exercise in hypertension.

We investigated how exercise training superimposed on chronic hypertension impacted left ventricular remodeling. Cardiomyocyte hypertrophy, apoptosis, and proliferation in hearts from female spontaneously hypertensive rats (SHRs) were examined. Four-month-old SHR animals were placed into a sedentary group (SHR-SED; n = 18) or a treadmill running group (SHR-TRD, 20 m/min, 1 h/day, 5 days/wk, 12 wk; n = 18).

Voluntary wheel running and pacing-induced dysfunction in hypertension.

Purpose: We examined how voluntary wheel running in the female, spontaneously hypertensive rat (SHR) impacts myocardial tolerance to pacing stress and determined whether direct adenylyl cyclase agonism via forskolin infusion improved myocardial performance during pacing.

Methods: Twenty-five 16-week-old female Wistar Kyoto (WKY, n = 8) and SHR (n = 17) were utilized. Animals within the SHR group were randomly assigned to a sedentary (SHR-SED, n = 8) or a voluntary wheel running (SHR-WHL, n = 9) group.

Effects of caloric restriction and exercise training on skeletal muscle histochemistry in aging Fischer 344 rats.

The purpose of this study was to determine the effects of calorie restriction and exercise on hindlimb histochemistry and fiber type in Fischer 344 rats as they advanced from adulthood through senescence. At 10 months of age, animals were divided into sedentary fed ad libitum, exercise (18 m/min, 8% grade, 20 min/day, 5 days/week) fed ad libitum, and calorie restricted by alternate days of feeding. Succinic dehydrogenase, myosin adenosine triphosphatase (mATPase at pH 9.

Dehydration and symptoms of delayed-onset muscle soreness in normothermic men.

Context: A dehydrated individual who performs eccentric exercise may exacerbate skeletal muscle damage, leading to structural, contractile, and enzymatic protein denaturation, in addition to the myofiber and connective damage resulting from the eccentric muscle tension.

Objective: To identify the effects of dehydration on 5 physiologic characteristics of delayed-onset muscle soreness (DOMS) in normothermic men after an eccentric exercise perturbation.

Design: Randomized group test-retest design.

Dehydration and symptoms of delayed-onset muscle soreness in hyperthermic males.

Context: Exercise in the heat produces cellular conditions that may leave skeletal muscle susceptible to exercise-induced microdamage. Delayed-onset muscle soreness (DOMS) is a clinical model of contraction-induced skeletal muscle injury.

Objective: To determine whether thermoregulation during exercise heat stress adversely affects muscle injury and the accompanying DOMS.

Sprint training improves postischemic, left ventricular diastolic performance.

We examined the effects of sprint training on left ventricular diastolic stiffness during normoxia and after ischemia-reperfusion (I/R). Thirty-seven, male Sprague-Dawley rats, weighing 150-175 g at the initiation of the experiment, were randomly assigned to a sedentary, control group (n = 20) or to a high-intensity, sprint-trained group (n = 17). Animals were trained 5 days/wk on a motor-driven treadmill for 6 wk.

Temporal Pattern of the Repeated Bout Effect of Eccentric Exercise on Delayed-Onset Muscle Soreness.

OBJECTIVE: To determine the temporal pattern of the repeated bout effect of eccentric exercise on perceived pain and muscular tenderness associated with delayed-onset muscle soreness (DOMS). DESIGN AND SETTING: Subjects completed 2 identical eccentric exercise bouts separated by 6, 7, 8, or 9 weeks. The experiment was conducted in a biokinetics research laboratory.

Differential effects of exercise training on skeletal muscle SERCA gene expression.

Introduction: Exercise training induces significant changes in the performance of skeletal muscle.

Purpose: To determine whether changes in the gene expression of rat hind-limb muscle sarcoplasmic reticulum Ca2+ -ATPase isoforms (SERCA1a and SERCA2a) in response to either moderate- or high-intensity exercise training underlie the functional remodeling.

Methods: SERCA1a and SERCA2a isoform mRNA expression was determined in predominantly fast-twitch, gastrocnemius muscle and predominantly slow-twitch, soleus muscle with northern analysis.