At baseline, the capillary this website blood flow velocity, as well as the response to provocation, was studied. The response to provocation was studied in three ways. The effect on resting CBV was assessed as the reduction of flow velocity in response to inhalation of cigarette smoke. Furthermore, the response to provocation was assessed at first by PRH alone and then PRH was repeated after smoking. This procedure was also repeated after two weeks of oral treatment with ascorbate. In a subset of subjects, the effect of vitamin E was assessed

in an identical manner. A miniature cuff was applied to the base of the investigated finger to allow arterial occlusions. Instant release of cuff pressure results in temporary hyperemia and TtP was thus measured as the time from the release of the occlusion to the maximal flow velocity during reactive hyperemia. TtP was assessed after a one-minute arterial occlusion with a cuff pressure of 200 mmHg [4]. Analysis of the video photometric capillaroscopic recordings was performed using the Capiflow® system (IM-Capiflow, Stockholm, Sweden). In humans, intravital capillaroscopy may be Paclitaxel molecular weight used to study

capillaries of the retina, lip, and skin. In this study, the nail fold of the finger was used where the terminal row of dermal capillary loops lies parallel to the surface of the skin. The capillary vessels form a unique pattern, whereby it is easy to recognize the same individual capillary at each examination both from a drawing and by reviewing the previous tape recording. Suitable capillaries with good contrast BCKDHA and visible signals were used at each session. The same capillary of each subject was examined at each occasion. The median value of three analyses of this capillary was used. The coefficient of variation between repeated measurements in a single capillary during a single session has been assessed as 6%, and the CV between different days as <13%, when the mean of at least two time-to-peak assessments at each occasion is used [39].

Care was taken to perform the examinations at the same temperature (ambient and digit skin temperature) and after at least 20 minutes of rest. The skin temperature was continuously measured using an electronic thermistor (Physitemps Instruments, Inc., Clifton, NJ, USA). The examinations were performed with the subjects seated and with the arm and hand supported at the heart level. Smoking, coffee, tea or heavy meals were not allowed in the two hours prior to examination. Blood pressure and heart rate were recorded at each occasion. Smoke inhalation consisted of the smoking of one cigarette (Marlboro®) (Philip Morris, Pittsburgh, PA, USA) in a well-ventilated room. A power analysis assuming the same effect of ascorbate as in previous acute experiments with an alpha of 0.05 resulted in a power exceeding 90% already with 12 subjects.