Controversies surrounding tympanic temperature (Tty) itself and techniques for measuring it have dampened the potential usefulness of Tty in determining core temperature (operationally defined here as the body temperature taken at a deep body site). The present study was designed to address the following questions. 1) Can a tympanic membrane probe be made that is safer and more reliable than its predecessors? 2) Why is the effect of facial cooling and heating on Tty so inconsistent in reports from different laboratories? 3) Is Tty still useful as a measure of core temperature? Data from this study, obtained with a modified thermocouple probe, suggest that the widely reported facial skin cooling effect on Tty is most probably due to thermal contamination from the surrounding ear canal wall and/or suboptimal contact of the probe sensor with the tympanic membrane because 1) Tty that fell during facial cooling was increased to the precooling level by the repositioning of the probe sensor; 2) Tty determined by using a probe with a larger sensor area (the sensor soldered to a steel wire ring)tended to fall in response to facial cooling, whereas Tty determined with a thermally insulated probe ring did not; and 3) Tty obtained under careful positioning of the insulated probe was relatively insensitive to facial cooling or heating. Because Tty was practically identical to esophageal temperature (Tes) in the steady state, i.e., 36.83 +/- 0.20 (SD) degrees C for Tty and 36.87 +/- 0.16 degrees C for Tes at room temperature (n = 11), and because facial cooling had little effect on both Tty and Tes (36.86 +/- 0.17 degrees C for Tty and 36.86 +/- 0.26 degrees C for Tes during facial or scalp skin cooling), we support the postulate that Tty is a good measure of core temperature. The temperature transient in response to foot warming was detected 5 min (n = 2) faster with Tty than with Tes. Thus, with further improvements in the design of the probe. Tty can become a standard for determination of core body temperature.

In freshly dissociated rhesus palm eccrine clear cells, regulatory volume increase (RVI) was studied using image analysis as a measure of Na-K-2Cl cotransport activity. Pseudo-RVIs, as well as RVI during methacholine (MCh)-induced cell shrinkage, were observed in clear cells and were inhibited by 100 microM bumetanide or in Na-free medium, but were not inhibited by amiloride or ouabain. RVI in hypertonic medium and RVI after MCh-induced cell shrinkage were accelerated by adenosine 3',5'-cyclic monophosphate (cAMP)-elevating agents (forskolin+isoproterenol) and inhibited by phorbol ester. RVI in hypertonic medium was enhanced by a phosphatase inhibitor, okadaic acid. mRNA for Na-K-2Cl cotransporter (NaKCC) was demonstrated in freshly isolated rhesus sweat secretory coils by polymerase chain reaction (PCR) after reverse transcription using a set of primers derived from the published human NaKCC (hNaKCC) 1 sequence, i.e., nucleotides 2,043-2,810. The deduced amino acid sequence of the PCR-amplified 767-base pair segment was identical to that of hNaKCC 1 from a human colon cell line (T84). The data are interpreted to indicate that NaKCC, showing strong homology to secretory type hNaKCC 1, is present in rhesus eccrine secretory coils and may participate in the cotransport component of eccrine sweat secretion and cell volume regulation, especially during cholinergic stimulation. The data also raise the possibility that sweat gland NaKCC may be upregulated by cAMP-mediated protein phosphorylation and downregulated by protein kinase C.

Cystic fibrosis transport regulator is a cAMP-dependent chloride channel protein. Normal (non cystic fibrosis) human epidermis stained positive for cystic fibrosis transport regulator as densely as did the eccrine sweat gland when three monoclonal antibodies for R (regulatory) and C (C-terminus) domains of cystic fibrosis transport regulator were used. All the layers of the epidermis took up staining uniformly. A peptide for C-epitope completely blocked the staining with monoclonal antibodies for C. Nested reverse transcription polymerase chain reaction of freshly isolated human epidermal fragments and the eccrine sweat glands amplified the cystic fibrosis transport regulator mRNA sequence derived from exons 13 and 14 to comparable extents. The 526 base pair antisense, but not sense, RNA probe derived from exons 10-13 stained cystic fibrosis transport regulator mRNA in both the epidermis and the sweat gland to a similar extent. In the epidermis, the cytoplasm of basal cells, stratum spinosum cells, and granular layer cells were all stained uniformly, but not corneocytes in the stratum corneum. In the sweat secretory coils, both clear and dark cells were stained but not the myoepithelium, with the dark cells staining more densely than the clear cells as in a previous study. In the duct, both luminal and basal ductal cells took up cystic fibrosis transport regulator staining uniformly but luminal cytoplasm of luminal ductal cells was devoid of cystic fibrosis transport regulator mRNA. Although the function of cystic fibrosis transport regulator in the epidermis is totally unknown, its recently proposed role as a universal regulator of a variety of cellular and membrane functions necessitates further studies on its regulation and function in health and disease.