RESUMO
The effects of different dopamine concentrations on contractility of myocardium with blocked α- or ß-adrenoceptors were examined in vitro in 21- and 100-day old rats. In myocardial strips with blocked α-adrenoceptors, dopamine (10-5 M) increased the right atrial contractile force. By contrast, this neurotransmitter (10-9-10-5 M) reduced the contractile force of atrial and ventricular strips with blocked ß-adrenoceptors.
Assuntos
Envelhecimento/fisiologia , Dopamina/farmacologia , Contração Isométrica/efeitos dos fármacos , Contração Miocárdica/efeitos dos fármacos , Receptores Adrenérgicos alfa/metabolismo , Receptores Adrenérgicos beta/metabolismo , Antagonistas Adrenérgicos alfa/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Animais , Animais não Endogâmicos , Átrios do Coração/efeitos dos fármacos , Ventrículos do Coração/efeitos dos fármacos , Contração Isométrica/fisiologia , Contração Miocárdica/fisiologia , Miocárdio/metabolismo , Fentolamina/farmacologia , Propranolol/farmacologia , Ratos , Técnicas de Cultura de TecidosRESUMO
A comprehensive study of the functional state of the sympathoadrenal system (SAS) and adrenal cortex (AC) in boys aged of 11-15 years, was carried out depending on their age, puberty stage and academic year period, on the basis of indices of the daily adrenaline (A), noradrenaline (NA), 17-ketosteroids (17-KS) and 17-oxyketosteroids (17-OKS) excretion. A certain synchronism of the manifestation offunctional activity of the SAS mediator level, glucocorticoid and androgen AC function is determined as boys grow older and during their pubertal changes. At the same time the different dynamics of the studied indices in boys aged of from 14 to 15 years and by the V puberty stage is marked. During the academic year changes of hormone and hormonal metabolite excretion, having a different focus and intensity in the age groups were observed: a significant decrease of age NA excretion and androgen metabolite indices (at 15) of 14 and 15 year-old teenagers at the end of the academic year is found out, against the backdrop of a substantial and long-term increase of glucocorticoids (February, April), with their dangerous catabolic effect on a child's body and their depressing effect on the immune response.
Assuntos
Adaptação Fisiológica/fisiologia , Desenvolvimento do Adolescente/fisiologia , Desenvolvimento Infantil/fisiologia , Hormônios , Puberdade/fisiologia , Adolescente , Criança , Hormônios/análise , Hormônios/sangue , Humanos , Masculino , Federação Russa/epidemiologia , Serviços de Saúde Escolar/estatística & dados numéricos , Maturidade Sexual/fisiologia , Estatística como AssuntoRESUMO
It was found that in 8-9-year-old children, the hormonal part of the sympathoadrenal system more rapidly develops in boys, while the transmitter part develops more rapidly in girls. The androgenic and glucocorticoid function of the adrenal cortex matures earlier in girls. To the end of the school year, excretion of epinephrine and norepinephrine decreased, which attests to the development of fatigue.
