Transcutaneous (tc) gasimetry has been employed for several decades as a technique to noninvasively assess oxygen tension (pO2) levels. It is valuable for early detection of lower limb ischemia in peripheral artery disease and diabetes, being a predictor for level of amputation. tcpO2 provides a continuous signal whose spectral organization is virtually unknown. Our aim was to assess the spectral organization of tcpO2 signals acquired during two experimental maneuvers destined to challenge circulatory homeostasis. Fifty-seven subjects (23.0 ± 4.0 y.o.) were enrolled in this study after giving informed written consent, and were subjected to two maneuvers while lying supine. Thirty-five subjects were subjected to a passive leg raising (PLR) test while twenty-two were subjected to a leg lowering test destined to evoke the venoarteriolar (VAR) reflex, both with the same structure – 10 min baseline, 10 min challenge, 10 min recovery. TcpO2 levels were collected from a distal region of the foot while LDF signals were acquired on the inferior aspect of the second toe. Both signals were decomposed with the wavelet transform (WT) to obtain the respective frequency spectra. The spectral organization of the LDF signal is well known (cardiac, respiratory, myogenic, sympathetic, endothelial NO-dependent, endothelial NO-independent). TcpO2 suffered opposite significant changes during both protocols – a decrease with PLR and an increase with VAR. In either protocol, tcpO2 spectra revealed three low-frequency spectral regions, partly overlapping the endothelial regions of the LDF spectra. These results suggest that although the tcpO2 signal is mainly from macrocirculatory origin, it might suffer a modest contribution from the endothelium.