Background-We sought to identify whether transcutaneous oxygen tension (tcPO 2 ) measurements could be used to noninvasively detect lesions in the arterial network supplying blood flow to the hypogastric circulation. Methods and Results-A study was undertaken in vascular patients with suspected (PC, nϭ43) and not with suspected (NPC, nϭ34) proximal ischemia. TcPO 2 was measured on both buttocks and with a chest reference electrode. Arteriography on the right or left side was positive for stenoses (Ն75%) or occlusion of one or more of the following arteries: the aorta, the common iliac arteries, or the internal iliac arteries.

Background-The maximal walking distance (MWD) performed on a treadmill test remains the "gold standard" in estimating the walking capacity of patients who have peripheral arterial disease with intermittent claudication, although treadmills are not accessible to most physicians. We hypothesized that global positioning system (GPS) recordings could monitor community-based outdoor walking and provide valid information on walking capacity in patients with peripheral arterial disease. Methods and Results-We studied 24 patients (6 women

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Low-cost, commercially available GPS may be accurate in studying outdoor walking, provided that simple data processing is applied. Future validation in diseased subjects could allow for the study of free-living walking capacity, such as maximal walking distance in vascular patients.

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Local pressure‐induced vasodilation (PIV) is a neural vasodilator response to non‐nociceptive externally applied pressure in the skin, previously described in humans. We first determined whether PIV exists in rats and depends on capsaicin‐sensitive fibres as it does in humans. We then examined the mediators involved in the efferent pathway of PIV. Cutaneous blood flow was measured by laser Doppler flowmetry during 11.1 Pa s−1 increases in local applied pressure in anaesthetized rats. The involvement of capsaicin‐sensitive fibres in PIV was tested in rats treated neonatally with capsaicin. To antagonize CGRP, neurokinin‐1, −2, or −3 receptors, different groups of rats were treated with CGRP8–37, SR140333, SR48968 or SR142801, respectively. Prostaglandins involvement was tested with indomethacin treatment. To inhibit nitric oxide synthase (NOS) activity or specific neuronal NOS, rats were treated with NG‐nitro‐L‐arginine or 7‐nitroindazole, respectively. PIV was found in rats, as in humans. PIV was abolished by neonatal treatment with capsaicin and by administration of CGRP8–37 but remained unchanged with SR140333, SR48968 and SR142801 treatments. Prostaglandin inhibition resulted in a significant decrease in PIV. Inhibition of NOS abolished PIV, whereas inhibition of neuronal NOS caused a diminution of PIV. These data suggest that PIV depends on capsaicin‐sensitive fibres in rats, as in humans. It appears that CGRP plays a major role in the PIV, whereas neurokinins have no role. Furthermore, PIV involves a contribution from prostaglandins and depends on endothelial NO, whereas neuronal NO has a smaller role. British Journal of Pharmacology (2000) 131, 1161–1171; doi:

To find whether the measurement of skin blood flow (SkBF) by laser-Doppler flowmetry (LDF) is influenced by blood flow to underlying skeletal muscle, five subjects performed mild forearm exercise to induce a metabolic hyperemia in muscle in both forearms. This exercise consisted of alternative opening and closing of both hands at a frequency of approximately 1/s for a duration of 3 min. This exercise was performed twice by each subject. Forearm blood flow (FBF) by plethysmography increased from 2.64 +/- 0.49 (rest) to 31.11 +/- 9.95 ml.100 ml-1.min-1 (immediately after exercise) (P less than 0.001). No statistically significant postexercise increase was observed in LDF measured on the dorsal (110 +/- 21 to 105 +/- 21 mV) or ventral surface (266 +/- 113 to 246 +/- 77 mV) of the forearm. LDF measured from the chest also showed no significant change, indicating that the exercise was too mild to have reflex effects on SkBF. Moreover, the slope of the logarithmic linear regression and the half-time for recovery during the postexercise period for FBF were not reflected in LDF measurements from any of the three sites. We conclude that LDF measured from the skin surface is not influenced by blood flow to underlying skeletal muscle.

Vascular and neurological mechanisms are both likely to be involved in foot ulcer. We recently reported a pressure-induced vasodilation (PIV), relying on unmyelinated afferent excitation. We previously found that cutaneous blood flow in response to locally applied pressure might be impaired in diabetic patients because of the combined effects of low cutaneous temperature and alterations in microcirculatory function. Therefore, we aimed to analyze whether, at a relatively high cutaneous temperature, PIV is present in type 1 diabetes and to assess endothelial-dependent vasodilation and endothelium-independent vasodilation. We measured cutaneous blood flow using laser Doppler flowmetry on the head of the first metatarsus in response to applied pressure at 5.0 mmHg/min in warm conditions (29.5 ؎ 0.2°C). Responses to iontophoresis of acetylcholine (endothelium dependent) and sodium nitroprusside (endothelium independent) were measured using laser Doppler flowmetry in the forearm. The data indicate that PIV exists at the foot level in normal subjects, whereas it was not found in diabetic patients. In diabetic patients, the nonendothelial-mediated response to sodium nitroprusside was preserved, whereas the endothelial-mediated response to acetylcholine was impaired. These findings might be relevant to the high prevalence of foot ulcer that occurs in diabetic patients. Diabetes 53: [721][722][723][724][725] 2004