Bubble imaging and TEWL measures with evaporimetry in two subjects (EB-02, 03) who were not stimulated.
(A-B) show sweat bubble imaging after 20 min with no applied stimulus (and with no atropine to block any baseline cholinergic secretion). (C-D) show evaporimetry traces at the same sites. The dashed line shows a stable and consistent difference between the two subjects of ~6 g/(m2·hr) or 10 nl/(cm2·min). The summed bubble secretion corrected for the 0.6 cm2 size of the imaged area was 13.4 nl/cm2 ·min. This agreement is at least as good as the agreement for bubble tests at same sites on different days shown in Fig 5. However, in subsequent tests with this subject no bubbles were observed in spite of the same TEWL (see text). (E) Distribution of single gland basal secretion rates for sweat bubbles (n = 66) shown in panel (B). Each point plots the volume (y-axis) and rank for an individual gland.