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At least 613 records · Page 34Linked to original sources
PubMed2003

[Effects of simulated weightlessness on reproduction in male rats].

OBJECTIVE: To study the effects of tail-suspension on gonad and spermatic hormone in male rats. METHOD: After tail-suspension and reambulation some times in male rats, weight of testis was measured, sperm of epididymis was inspected, morphology of testicular cell was compared, and antent of testosterone assay by radioimmunoassay ratio of LH-beta positive cell in pituitary was measured by immunohistochemic. RESULT: After tail-suspension, weight of testis in male rats decreased significantly. Shape of the convoluted tubules and number of all levels of the spermatocyte in testis atrophied markedly. No sperm was found in the epididymis. Content of testosterone decreased markedly. Number of positive cell of beta-subunit of LH in the pituitary increased markedly. CONCLUSION: Tail-suspension has negative effect on sex gland and reproduction function of male rats.

Animals↗
PubMed1992

Designing methods for musculoskeletal conditioning in weightlessness.

There is an immediate need to find methods to combat the skeletal muscle deconditioning that occurs in microgravity. Important features to be considered for any ergometer or exercise method to be used as a countermeasure against musculoskeletal deconditioning in space include heavy muscular loading of the postural muscles of the lower limbs and that eccentric and concentric muscle activations can be performed. Those are major requirements to produce optimal gains in strength and muscle mass at 1-g and probably to counteract muscle atrophy and strength loss in microgravity. Resistance exercise with a strength-ergometer, using the fly-wheel principle was carried out at a low oxygen cost and required no external power supply. We have developed a resistance training system employing this ergometer so that force and power production easily can be monitored and calibrated. It is suggested that the features of this ergometer meet the presented requirements for use during long-term space missions.

Animals↗
PubMed2004

Feasibility of real-time 3D echocardiography in weightlessness during parabolic flight.

Aim of the study was to test the feasibility of transthoracic real-time 3D (Philips) echocardiography (RT3D) during parabolic flight, to allow direct measurement of heart chambers volumes modifications during the parabola. One RT3D dataset corresponding to one cardiac cycle was acquired at each gravity phase (1 Gz, 1.8 Gz, 0 Gz, 1.8 Gz) during breath-hold in 8 unmedicated normal subjects (41 +/- 8 years old) in standing upright position. Preliminary results, obtained by semi-automatically tracing left ventricular (LV) and left atrial (LA) endocardial contours in multiple views (Tomtec), showed a significant (p<0.05) reduction, compared to 1 Gz, of LV and LA volumes with 1.8 Gz, and a significant increase with 0 Gz. Further analysis will focus on the right heart.

Adult↗
PubMed2005

[Serum creatine kinase levels and the number of sarcolemmal dystrophin disruptions in human skeletal muscle fibers under conditions of weightlessness simulation].

9 male volunteers took part in the experiment. They were divided in two groups. 5 volunteers (control group) have been in "dry" immersion for 7 days. 4 volunteers (stimulated group) in addition to "dry" immersion were treated with artificial support stimulation. We investigated the number of muscle fibers with the disruptions of sarcolemmal dystrophin and serum creatine kinase levels. 7-day "dry" immersion did not change the mean number of muscle fibers with dystrophin disruptions, it led to significant decrease of serum creatine kinase levels and did not influence on the sensitivity of sarcolemma to injury. Artificial support stimulation did not influence on these parameters.

Adult↗