Influence of temperature gradual variation over skin microcirculation responses to thermal stimulation

  • Pedro Contreiras Pinto Universidade Lusófona de Humanidades e Tecnologias
  • Helena Vargas Universidade Lusófona de Humanidades e Tecnologias
  • Luis Monteiro Rodrigues Universidade Lusófona de Humanidades e Tecnologias
Palavras-chave: Microcirculation, thermal hyperemia, Laser Doppler


The study of the mechanisms involved in the local temperature control is a model used to understand vascular pathology, especially when endothelium dysfunction is the issue. This study aims to systematize and to compare the response to local changes in temperature, by studying the influence of the heating rate over the response. Several local heating protocols working at 42 or 44ºC were performed in the forearm of healthy, female, non smokers volunteers (n=10). Skin microcirculation was evaluated by Laser Doppler Flowmetry during 30 minutes. A new parameter “nadir/peak” (N/P) was calculated to distinguish the shape of the hyperemic response - biphasic when N/P <1 and monophasic when N/P >1. At 42ºC the shape is biphasic, independently of the rate of heating. At 44ºC the shape was always monophasic. This suggested that local response to heating is dependent from the rate of heating and probably from the activation of nociceptor fibers.
Ciências Biomédicas / Biomedical Sciences