Effects of eccentric exercise on anaerobic power, starting speed and anaerobic endurance

The aim of this study was to evaluate the effects of eccentric exercise on anaerobic power, starting speed and anaerobic endurance. The participants performed the maximum cycling sprint test (MCST) prior to eccentric exercise (ECC), 10 minutes after, as well as one hour, 24 hours, 48 hours, and one week after ECC. The peak and mean power, time to attain peak power, time of maintaining peak power and power decrease were measured in the MCST. Before and after ECC, the myoglobin concentration (Mb) in the blood plasma was measured. After ECC, a significant (p<.05) increase in Mb was observed. A significant (p<.05) decrease was noted in peak (-.92±0.42 W.kg-1) as well as in mean power (-.57±0.36 W.kg-1) immediately after ECC. A significant (p<.05) decrement of these indicators lasted for at least 24 hours after ECC. Eccentric exercise did not affect starting speed (time to attain peak power) and anaerobic endurance (time of maintaining peak power and power decrease during MCST)

Ultrastructure of the ventromedial hypothalamic nucleus in fasted and refed young and old rats

Many hypothalamic nuclei are involved in the regulation of food intake and energy homeostasis. An ultrastructural investigation of the hypothalamic ventromedial nucleus (VMN), a hypothetical "satiety centre" was performed to explore the morphological basis of altered feeding behaviour of old rats in an experimental model of fasting/refeeding. Young (5 months old, n = 12) and old (24 months old, n = 12) male Wistar rats were fasted for 48 hours, then refed for 24 hours and sampled thereafter. Brain tissue was fixed by perfusion, histological and ultrathin sections were obtained by routine methods. Although food intake was similar in control young and old rats, during refeeding old animals consumed less chow than young ones. The EM analysis of VMN neurones of old control rats revealed, besides typical age-related residual bodies, deep indentations of the nuclear envelope and the presence of long, undulating rough endoplasmic reticulum cisternae in the cell periphery. In both young and old rats fasting for 48 hours led to the expansion of Golgi complexes and increased folds of the nuclear envelope, which is suggestive of enhanced cellular activity of the VMN neurones. These fasting-induced alterations were sustained in the VMN neurones of refed rats in both age groups. The results showed that the VMN neurones of old control rats differ at the ultrastructural level from young ones. However, starvation and subsequent refeeding cause similar alterations in the hypothalamic neurones of "satiety centre" of both young and old rats

The effect of fasting and refeeding on the ultrastructure of the hypothalamic paraventricular nucleus in young and old rats

In order to explore the morphological basis of the altered feeding behaviour of old rats, an ultrastructural investigation of the magnocellular neurons of the hypothalamic paraventricular nucleus (PVN) was performed. Young and old male Wistar rats, 5 and 24 months old, respectively, and with each age group comprising 12 animals, were divided into 3 groups. The rats in Group I were used as controls (normally fed), the rats of Group II were fasted for 48 hours and in Group III the rats were fasted for 48 hours and then refed for 24 hours. The brains were fixed by perfusion and histological and ultrathin sections were obtained by routine methods. Common features of the magnocellular PVN neurons of young and old rats were abundant Golgi complexes and short fragments of RER localised at the cell periphery. In contrast to young rats, the PVN neurons of old animals showed deep indentations of the nuclear envelope and agerelated residual bodies. In both age groups fasting for 48 hours led to the expansion of the Golgi complexes and dilatation of RER cisternae. In contrast to those in fed rats, RER cisternae in the neurons of old fasted animals were situated between the nuclear envelope and the Golgi zone. Prolonged RER cisternae were distributed in the peripheral cytoplasm of refed old rats. Our observations suggest that at the ultrastructural level the process of ageing does not change the responsiveness of magnocellular PVN neurons to fasting-refeeding

Echocardiographic evaluation of cardiovascular system in adolescent athletes in view of physiological adaptation to physical training

Wstęp. Ocena układu krążenia u młodych sportowców pozostaje tematem aktywnych badań. Duże trudności pojawiają się w zakresie oceny wielkości i grubości jam serca ze względu na istotne różnice antropometryczne między poszczególnymi zawodnikami gdzie trening fizyczny (nierzadko bardzo intensywny) nakłada się na okres dojrzewania i szybkiego wzrostu. Celem pracy była ocena wpływu regularnego wysiłku fizycznego na układ krążenia u dorastających sportowców. Materiał i metody. W badaniu oceniano 89 sportowców — 41 jeden piłkarzy oraz tenisistów (grupa 1.) oraz 48 rozpoczynających karierę sportową wioślarzy (grupa 2.). U wszystkich kwalifikujących się zawodników wykonano badanie ergospirometryczne z oceną szczytowego pochłaniania tlenu (VO2max) oraz badania elektrokardiograficzne i echokardiograficzne. Wyniki. Porównano sportowców z obu grup, tj. piłkarzy i tenisistów (grupa 1.) z grupą wioślarzy (grupa 2.). Obie grupy nie różniły się wiekiem (14,2 ± 1,1 v. 14,3 ± 1,2 roku; p = NS) oraz płcią (dziewczęta: 6 [7,6%] v. 8 [10,2%]; p = NS]. Dłużej trenujący piłkarze i tenisiści, w porównaniu z grupą wioślarzy, różnili się pod względem parametrów antropometrycznych, parametrów wydolności fizycznej oraz spoczynkowej częstości rytmu serca. Większość wymiarów jam serca indeksowanych względem pola powierzchni ciała była większa w grupie osób dłużej trenujących piłkarzy i tenisistów (końcoworozkurczowy wymiar lewej komory: 29,1 ± 2,5 v. 26,8 ± 2,7 mm/m2; p &lt; 0,001; grubość przegrody międzykomorowej: 6,0 ± 0,7 v. 5,4 ± 0,8 mm; p = 0,001; grubość ściany tylnej: 0,8 ± 0,6 v. 5,2 ± 0,6; p &lt; 0,001; proksymalny fragment drogi odpływu prawej komory: 16,1 ± 2,2 v. 14,5 ± 2,0 mm/m2; p = 0,001; wymiar drogi napływu prawej komory: 19,9 ± 2,1 v. 18,5 ± 2,6 mm/m2; p = 0,01). Po zastosowaniu indeksacji allometrycznej większość oberwanych różnic przestała mieć znaczenie istotne statystycznie, z wyjątkiem indeksowanej masy lewej komory (87,0 ± 13,9 v. 76,8 ± 12,2 g/(m2)1,5; p = 0,001). Wnioski. 1. Zastosowanie indeksacji allometrycznej w stosunku do parametrów echokardiograficznych u dorastających sportowców wydaje się właściwe ze względu na nieliniową zależność pomiędzy tempem wzrostu, a szybkością zwiększania się narządów wewnętrznych w tej grupie wiekowej. 2. Nawet krótki trening fizyczny u dorastających sportowców ma istotny wpływ na poprawę parametrów wydolności fizycznej, bez znaczącego wpływu na większość parametrów morfologicznych serca.Introduction. Assessment of cardiovascular system in young athletes is a subject of active research. Cardiac morphology is difficult to evaluate due to significant anthropometric differences between individuals, especially during puberty and growth spurt. The aim of this paper was an assessment of systematic physical training’s impact on cardiovascular system and cardiac remodeling in young athletes. Material and methods. Study involved 89 adolescent athletes, including 41 football players and tennis players (group 1) and 48 beginner rowers (group 2). All athletes included in the study underwent ergospirometric tests with evaluation of peak oxygen uptake (VO2max) as well as a 12-lead electrocardiographic and echocardiographic evaluation. Results. Athletes in group 1 (football/tennis players) were compared to group 2 (rowers). There were no significant differences in age (14.2 ± 1.1 vs. 14.3 ± 1.2 years, p = NS) or sex (6 [7.6%] vs. 8 women [10.2%], respectively, p = NS). Differences were observed in anthropometric parameters, cardiopulmonary fitness, and resting heart rate. Most parameters of cardiac morphology indexed to body area (indexed value: raw data/bodu surface area) were greater in group 1 (left ventricular end-diastolic dimension 29.1 ± 2.5 vs. 26.8 ± 2.7 mm/m2, p &lt; 0.001; septal thickness: 6.0 ± 0.7 vs. 5.4 ± 0.8 mm, p = 0.001; posterior wall thickness: 0.8 ± 0.6 vs. 5.2 ± 0.6, p &lt; 0.001; proximal part of right ventricle outflow tract: 16.1 ± 2.2 vs. 14.5 ± 2.0 mm/m2, p = 0.001; right ventricle inflow tract: 19.9 ± 2.1 vs. 18.5 ± 2.6 mm/m2, p = 0.01). When allometric scaling was employed, most differences were insignificant, apart from indexed left ventricle mass (87.0 ± 13.9 vs. 76.8 ± 12.2 g/(m2)1.5, p = 0.001). Conclusions. 1. Allometric indexation of echocardiographic parameters in young athletes is appropriate since relationship between body height increase and the rate of internal organ growth in these subjects is non-linear. 2. Even a short physical training in young athletes has impact on their condition but does not significantly affect parameters of cardiac morphology

Detection of psychotropic substances in the blood by LC/MS/MS

Z roku na rok obserwuje się wzrost zjawiska zażywania środków uzależniających. Prowadzi to do pojawiania się problemu związanego z uzależnieniem jak również zażywanie środków psychoaktywnych stwarza duże zagrożenie dla uczestników ruchu drogowego. Rozporządzenie Ministra Zdrowia w sprawie środków działających podobnie do alkoholu oraz warunków i sposobu przeprowadzenia badań na ich obecność w organizmie człowieka nakłada odpowiednie kryteria warunkujące wykonanie badań. Istotnym czynnikiem z punktu widzenia opiniodawczego jest znajomość budowy chemicznej substancji należących do poszczególnych grup środków uzależniających, ich przemian metabolicznych, które zachodzą w ustroju jak również działania na organizm. Ma to na celu pomóc w prawidłowej interpretacji uzyskiwanych wyników badań analitycznych.Year on year, one can observe an increase in the use of addictive substances. This leads to occurring the problem of addiction as well as the use of psychoactive substances as a serious hazard to road users. The Regulation of the Minister of Health on agents acting similarly to alcohol and the conditions and manner of conducting research on their presence in the human body, requires adequate benchmarks for performing these tests. An important factor, from consultative point of view, is the knowledge of the chemical structure of substances belonging to different groups of drugs of abuse, their metabolic transformations that occur in the body as well as their influence on the body. This is to aid in the proper interpretation of the results of the analytical tests

THE ROLE OF SALIVARY IMMUNOGLOBULIN A IN THE PREVENTION OF THE UPPER RESPIRATORY TRACT INFECTIONS IN ATHLETES – AN OVERVIEW

Athletes subjected to high work loads may experience temporary suppression of the functions in the immune system which increases the susceptibility to infections of such subjects. Namely, upper respiratory tract infections (URTI) are the most common disorders among individuals subjected to high work loads and that issue is of utmost importance for sport immunologists. So far, no simple explanation has been offered as to the specific roles of detailed elements of the immune system in URTI incidence. One of the most likely markers is supposed to be the secretory immunoglobulin A (sIgA), associated with mucosal membranes of upper respiratory  tracts, although the results are far from being unequivocal yet. The most important results published in that area were discussed in this paper

GENES IN SPORT AND DOPING

Genes control biological processes such as muscle production of energy, mitochondria biogenesis, bone formation erythropoiesis, angiogenesis, vasodilation, neurogenesis, etc. DNA profiling for athletes reveals genetic variations that may be associated with endurance ability, muscle performance and power exercise, tendon susceptibility to injuries and psychological aptitude. Already, over 200 genes relating to physical performance have been identified by several research groups. Athletes’ genotyping is developing as a tool for the formulation of personalized training and nutritional programmes to optimize sport training as well as for the prediction of exercise-related injuries. On the other hand, development of molecular technology and gene therapy creates a risk of non-therapeutic use of cells, genes and genetic elements to improve athletic performance. Therefore, the World Anti-Doping Agency decided to include prohibition of gene doping within their World Anti-Doping Code in 2003. In this review article, we will provide a current overview of genes for use in athletes’ genotyping and gene doping possibilities, including their development and detection techniques