Trans-epithelial potential

Tamaoki, J., Takemura, H., Tagaya, E., and Konno, K. (1995). Effect of clarithromycin on trans-epithelial potential difference in rabbit tracheal mucosa. J. Infect. Chemother. 1, 112-115. 

Rapp, P. E. Berridge, M. J. The control of trans-epithelial potential oscillations in the salivary gland of Calliphora erythrocephala. J. Exp. Biol. 1981, 93, 119-132. 

Fig. 11.4. Model for cholinergic signalling in the intestinal mucosa, providing a possible rationale for AChE secretion by parasitic nematodes. ACh released from enteric cholinergic motor neurons stimulates chloride secretion, mucus secretion and Paneth cell exocytosis through muscarinic receptors. Secretory responses may be modulated by mast cell mediators, either directly or via the induction of neural reflex programmes. The role of muscarinic receptor-positive cells in the lamina propria of rats infected with N. brasiliensis is undetermined, as are potential mechanisms of trans-epithelial transport of the enzymes. Adapted from Cooke (1984).

A series of 6-phenylpyrrolo[2,3-fc]pyrazines, initially described as CDK/GSK-3 inhibitors, were also shown to potentiate CFTR (wt, F508del, and G551D) [54]. Compound 10 was shown to potentiate multiple CFTR mutants with submicromolar affinity (140-152 nM on wt-CFTR (calu-3 and CHO cells), 1.5 nM on G551D (CHO cells), and lllnM on F508del-CFTR (temperature corrected CF15 cells)) and to stimulate trans-epithelial ion transport in the proximal colon of mice (wt) under short-circuit conditions with an affinity of 90 nM. 

Epithelia like those of the small intestine, proximal renal tubule, and gall bladder are characterised by low or negligible transepithelial potential, low trans-epithelial resistance, and high hydraulic conductivity, and the shunt conductance is a large fraction of the total transepithelial conductance. These epithelia are able to transport large volumes of isotonic fluid. 

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