5°C above baseline. Thereafter, they were immersed in a different water tank maintained at 12°C water temperature until their rectal temperature was decreased by 0.5°C below
baseline. This procedure was conducted twice. Auto-Regressive Integrated Moving Average analysis showed that fluctuations in finger blood flow were associated with changes in mean body temperature (Ljung-Box statistic >0.05; R2 = 0.67) and body heat storage (Ljung-Box statistic >0.05; R2 = 0.70), but not with rectal (Ljung-Box statistic check details <0.05; R2 = 0.54) or tympanic (Ljung-Box statistic <0.05; R2 = 0.49) temperatures. It is concluded that reflex alterations in finger blood flow during repetitive hot and cold water immersions are associated with see more mean body temperature and the rate of body heat storage, but not with rectal and tympanic temperatures. “
“Please cite this paper as: Henriksson, Diczfalusy and Freyschuss (2012). Microvascular Reactivity in Response to Smoking and Oral Antioxidants in Humans. Microcirculation 19(1), 86–93. Objective: To investigate whether a daily intake of a moderate dose
of antioxidants modifies the microcirculatory response to smoking, assuming a major influence of oxidative stress on microcirculation. Methods: The microvascular response to smoking was assessed in individual capillaries by capillaroscopy before and after two weeks of treatment with oral antioxidants. Results: Smoking prolonged time to peak (TtP) capillary blood flow velocity in all subjects. When the subjects were pre-treated with ascorbate, TtP was comparable to baseline values of untreated subjects. No significant effect of vitamin E was observed either before or after smoking. Capillary blood flow velocity increased after treatment with ascorbate as well as after vitamin E. However, significant reductions in velocity were still observed only in response to smoking even after subjects consumed
ascorbate and vitamin E (p < 0.0004 and p < 0.000008 respectively). Conclusions: This study focused on individual capillaries, and confirms that smoking has a very pronounced, direct and reproducible microvascular effect possible to demonstrate in vivo in human capillaries. Moderate intake of the antioxidant ascorbate clearly mitigated the effects induced by smoking. TtP after smoking in subjects treated with ascorbate was similar to that observed in untreated subjects before smoking a cigarette. Thus, oxidative stress could be assumed to play a role in the effects of smoking on microcirculation. Effects of antioxidants in vivo continue to bewilder science, with contradictory results from different studies. A large body of research has indicated an important role of oxidative processes for vascular function and in the development of atherosclerosis [7,58,67].