6 research outputs found
Efeitos hemorreolĂłgicos e cardiovasculares da eritropoietina num modelo de rato em exercĂcio fĂsico sob a acção de drogas
Recombinant human erythropoietin
(rhEPO) has been therapeutically
used for correction of anaemia. However,
due to the increase in circulating
red blood cells (RBCs) it promotes,
thus increasing oxygen delivery to
muscles and improving performance
in sport, it has been also illegally used
as sports doping. Besides the well
known increase of hematocrit and
blood viscosity; which might cause
serious complications for the athletes,
other disturbances could occur, whose
mechanisms remain to be fully elucidated.
This study aimed to evaluate
the hemorheological and cardiovascular
effects of administration of
rhEPO to rats under chronic aerobic
exercise. A ten week-protocol was
performed in four male Wistar rat
groups: control — sedentary; rhEPO
— 50 IV/kg, 3 times/wk; exercised
(EX) — swimming for 1 hr, 3 times/
wk; EX+rhEPO. rhEPO in trained
rats promoted erythrocyte count increase,
hypertension, heart hypertro-phy, sympathetic and serotonergic
overactivation, as well as a trend to
increased oxidative stress. In conclusion,
rhEPO doping in rats under
chronic exercise promotes not only
the expected increased hematocrit,
but also other serious deleterious cardiovascular
and thromboembolic
modifications, including live risk,
which might be known and assumed
by all sports authorities, including
athletes and their physicians.info:eu-repo/semantics/publishedVersio
Photolabile protection for amino acids: studies on the release from novel benzoquinolone cages
The synthesis of a novel fused nitrogen heterocycle, benzoquinolone, for evaluation as a photocleavable protecting group is described for the first time, by coupling to model amino acids (alanine, phenylalanine and glutamic acid). Conversion of the phenylalanine ester conjugate to the thionated derivative was accomplished by reaction with Lawesson’s reagent. Photocleavage studies of the carbonyl and thiocarbonyl benzoquinolone conjugates in various solvents and at different wavelengths (300, 350 and 419 nm) showed that the most interesting result was obtained at 419 nm for the thioconjugate, revealing that the presence of the thiocarbonyl group clearly improved the photolysis rates, giving practicable irradiations times for the release of the amino acids (less than 1 minute).Fundação para a Ciência e Tecnologia (FCT