| Autor: |
MEHTA, PRABHU N., PANITCH, HOWARD B., WOLFSON, MARLA R., SHAFFER, THOMAS H. |
| Zdroj: |
Pediatric Research (Ovid); May 1991, Vol. 29 Issue: 5 p446-448, 3p |
| Abstrakt: |
Xanthine derivatives relax adult airway smooth muscle (ASM). To determine whether caffeine and theophylline relax preterm ASM contracted by acetylcholine, 27 tracheal rings obtained from seven preterm lambs (120–135 d gestation) were studied. ASM was contracted using 10-5M acetylcholine (control) after the muscle was stretched to the length at which maximum active tension was developed isometrically. Concentration-effect curves for each xanthine were obtained by cumulative addition of the drug. Theophylline produced a significant decrease (p< 0.001) in active tension at each dose, whereas caffeine significantly increased (p< 0.001) active tension at 10-4and 10-3M concentrations. Addition of caffeine and theophylline to previously uncontracted ASM did not alter tension. Thus, it appears that, in contrast to their effect on adult ASM, the xanthine derivatives caffeine and theophylline have differential effects on prestimulated ASM in preterm lambs. These findings raise important questions about various aspects of the current therapeutic use of caffeine and theophylline. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
