Alteration of performance in a mouse model of Emery-Dreifuss muscular dystrophy caused by A-type lamins gene mutation.

Autosomal Emery-Dreifuss muscular dystrophy (EDMD) is caused by mutations in the lamin A/C gene (LMNA) encoding A-type nuclear lamins, intermediate filament proteins of the nuclear envelope. Classically, the disease manifests as scapulo-humero-peroneal muscle wasting and weakness, early joint contractures and dilated cardiomyopathy with conduction blocks; however, variable skeletal muscle involvement can be present. Previously, we and other demonstrated altered activity of signaling pathways in hearts and striated muscles of LmnaH222P/H222P mice, a model of autosomal EDMD.

A Mouse Model of Cardiomyopathy Induced by Mutations in the Hemochromatosis HFE Gene.

Background: The heart is 1 of the organs most affected by hereditary hemochromatosis (HH). The clinical impact of cardiomyopathy in patients with HH requires a particular diagnosis and less invasive treatments. We developed a model of cardiomyopathy in knockout (KO) mice for the high-Fe (HFE) gene and assessed left ventricular (LV) function and structure from 7-20 months.

Effect of constitutive inactivation of the myostatin gene on the gain in muscle strength during postnatal growth in two murine models.

Introduction: The effect of constitutive inactivation of the gene encoding myostatin on the gain in muscle performance during postnatal growth has not been well characterized.

Methods: We analyzed 2 murine myostatin knockout (KO) models, (i) the Lee model (KO ) and (ii) the Grobet model (KO ), and measured the contraction of tibialis anterior muscle in situ.

Results: Absolute maximal isometric force was increased in 6-month-old KO and KO mice, as compared to wild-type mice.

Prediction of one-repetition maximum from submaximal ratings of perceived exertion in older adults pre- and post-training.

Background: Individual's one-repetition maximum (1-RM) is required to calculate and prescribe intensity for resistance training, while testing protocols enhance the risk of injuries and are time-consuming.

Aims: The aim of the present study was to assess the accuracy of 1-RM prediction from ratings of perceived exertion (RPE) of resistance exercises performed at submaximal sets (intensity and volume) in older adult males before and after a 12-week rehabilitation program.

Methods: 18 untrained subjects (70.

Short-term glucocorticoid intake improves exercise endurance in healthy recreationally trained women.

The present study investigated whether short-term oral administration of glucocorticoid would modify performance and selected hormonal and metabolic parameters during submaximal exercise in healthy women. Nine recreational female athletes completed cycling trials at 70-75% VO(2) max until exhaustion after either placebo (Pla, gelatin) or oral prednisone (Cor, Cortancyl, 50 mg per day for 1 week) treatment, according to a double-blind and randomized protocol. Blood samples were collected at rest; after 10, 20, and 30 min of exercise; at exhaustion; and after 10 and 20 min of passive recovery for adrenocorticotrophic hormone (ACTH), dehydroepiandrosterone (DHEA), prolactin (PRL), growth hormone (GH), insulin (Ins), blood glucose (Glu), and lactate (Lac) determination.