Avaliação do efeito da temperatura sobre a dinâmica da resposta microcirculatória cutânea
Miniatura indisponível
Ficheiros
Data
2008
Título da revista
ISSN da revista
Título do Volume
Editora
Edições Universitárias Lusófonas
Resumo
De há muito que se conhecem as influências da variação da temperatura da pele sobre a microcirculação embora os
mecanismos e vias envolvidos nesta resposta reflexa não estejam totalmente identificados, pelo que os autores
entenderam estudar a resposta da pele in vivo ao aquecimento local. O estudo foi realizado no antebraço de 10
voluntários saudáveis (mulheres, entre os 20 e 35 anos de idade média: 25 ± 3,7). Após aclimatação as voluntárias
foram submetidas a um protocolo de aquecimento a duas temperaturas (42 e 44ºC) durante 40 minutos, sendo as
variações seguidas por meios não invasivos (PTEA perda trans-epidérmica de água e LDF perfusão sanguínea por
fluxometria de laser doppler).A resposta medida por LDF foi diferente nas temperaturas de 42 e de 44 ºC.A42ºC a resposta é bifásica (resposta típica) ao contrário do que sucede aquando do aquecimento a 44ºC. Neste caso, para
além da intensidade ser maior é atingido de imediato um platô, sugerindo a presença de um outro mecanismo
regulatório local. Relativamente à PTEAverificou-se um aumento semelhante em ambas as temperaturas, não tendo sido observadas diferenças estatisticamente significativas. O aquecimento a diferentes temperaturas parece colocar em evidência diferentes mecanismos de regulação da temperatura local.
Although it has long been known that variations in temperature can affect microcirculation, the mechanisms and pathways involved in this reflex response have not yet been completely identified. For this reason the authors resolved to study the response to local heating in vivo. The study was conducted on the forearms of 10 healthy volunteers (women between the ages of 20 and 35 years; mean: 25 ± 3.7). After the volunteers were acclimated, they were subjected to two temperature increases (to 42ºC and 44ºC) for 40 minutes and changes were measured by non- invasive means (TEWL trans-epidermic water loss, and LDF laser Doppler flowmetry to measure blood perfusion). Different responses were observed to the two temperatures on the LDF measurments. At 42ºC the response is biphasic (a typical response), but it is not when the temperature is increased to 44ºC. In the latter case, the intensity of the response is greater and it reaches a plateau immediately, which suggests the presence of another local regulatory mechanism. The TEWL shows a similar increase at both temperatures, with no statistically significant differences observed. Heating to different temperatures appears to trigger different mechanisms of local temperature regulation.
Although it has long been known that variations in temperature can affect microcirculation, the mechanisms and pathways involved in this reflex response have not yet been completely identified. For this reason the authors resolved to study the response to local heating in vivo. The study was conducted on the forearms of 10 healthy volunteers (women between the ages of 20 and 35 years; mean: 25 ± 3.7). After the volunteers were acclimated, they were subjected to two temperature increases (to 42ºC and 44ºC) for 40 minutes and changes were measured by non- invasive means (TEWL trans-epidermic water loss, and LDF laser Doppler flowmetry to measure blood perfusion). Different responses were observed to the two temperatures on the LDF measurments. At 42ºC the response is biphasic (a typical response), but it is not when the temperature is increased to 44ºC. In the latter case, the intensity of the response is greater and it reaches a plateau immediately, which suggests the presence of another local regulatory mechanism. The TEWL shows a similar increase at both temperatures, with no statistically significant differences observed. Heating to different temperatures appears to trigger different mechanisms of local temperature regulation.
Descrição
Revista Lusófona de Ciências e Tecnologias da Saúde
Palavras-chave
MEDICINA, MEDICINE, DERMATOLOGIA, DERMATOLOGY, ESTUDOS DE CASO, CASE STUDIES, TEMPERATURA CORPORAL, BODY TEMPERATURE, MICROCIRCULAÇÃO CUTÂNEA, CUTANEOUS MICROCIRCULATION