Effect of Clarithromycin on Transepithelial Potential Difference in Rabbit Tracheal Mucosa

• Published in: Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy Vol. 1; no. 2; pp. 112 - 115
• Main Authors: Tamaoki, Jun, Takemura, Hisashi, Tagaya, Etsuko, Konno, Kimio
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 1995
• Subjects: clarithromycin; cloride ion transport; rabbit; tracheal mucosa; cloride ion transport; clarithromycin; tracheal mucosa; rabbit
• ISSN: 1341-321X; 1437-7780
• DOI: 10.1007/BF02348754

Erythromycin's effectiveness in treating chronic airway diseases such as panbroncholitis may derive from its ability to inhibit chloride ion (Cl−) transport across airway mucosa, and hence to alleviate the excess sputum secretion characteristic of these disorders. To determine whether the newly developed macrolide antibiotic clarithromycin (CAM) has a similar effect, we studied its influence on the Cl− diffusion potential difference (Cl-PD) across rabbit tracheal mucosa using a high-impedance voltmeter under open-circuit conditions in vivo. Superfusion of the tracheal mucosal surface with 10−5 or 10−4M CAM in the presence of the sodium-channel blocker amiloride had no effect on the CI-PD. Intravenous administration of CAM at 10 mg/kg, however, caused a rapid decrease in Cl-PD from 10.8 ± 0.7 to 6.9 ± 0.4mV (P<0.001). This effect was dose-dependent: The maximum decrease from baseline CI-PD was 5.6 ± 0.9mV (P<0.001), and the dose of CAM required to produce a half-maximal effect (EC50) was 2.7mg/kg. Intravenous erythromycin decreased CI-PD to the same extent, whereas aminobenzyl penicillin, cefazolin and amikacin had no effect. These results suggest that CAM may inhibit Cl− secretion by airway epithelial cells in vivo, consequently decreasing water movement from the submucosa to the mucosa and perhaps inhibiting airway secretion.