A. Uemura, Y. Fujii, H. Toyooka
Jun 1, 2003
Citations
0
Influential Citations
7
Citations
Quality indicators
Journal
Anesthesia & Analgesia
Abstract
Olprinone, a phosphodiesterase III inhibitor, improves the contractility in fatigued diaphragm in vivo, but no data are available for the treatment and prevention of fatigue-induced changes in vitro. We therefore examined the efficacy of Olprinone for the treatment and prevention of fatigue-induced changes in guinea-pig diaphragmatic contractility. The guinea-pig diaphragm strips were randomly allocated according to dose of Olprinone (0, 10−6, 10−5, and 10−4 M) (n = 7 each) and were stimulated directly in an organ bath. Diaphragmatic contractility was measured by assessing twitch tension and force at 20-Hz and 100-Hz stimulation. Diaphragmatic fatigue was induced by generating rhythmic, repetitive contractions produced by 20-Hz stimulation for 5 min. In the first experiment, after the fatigue-producing period, Olprinone was administered to the organ bath for 5 min. In the second experiment, Olprinone was pretreated for 5 min, and then diaphragmatic fatigue was produced. In Experiment 1, after a fatigue-producing period, tetanic force to each stimulus decreased from baseline values (P < 0.05). Olprinone 10−5–10−4 M caused an increase in force at both stimuli from fatigued values (P < 0.05). In Experiment 2, no change in tetanic force was observed by pretreatment with Olprinone (0–10−4 M). After producing fatigue, tetanic force to each stimulus decreased from baseline values (P < 0.05). These results suggest that Olprinone 10−5–10−4 M improves the fatigue-induced changes in guinea-pig diaphragmatic contractility and that pretreatment with Olprinone does not prevent diaphragmatic fatigability. IMPLICATIONS: Olprinone is effective for the treatment, but not prevention, of fatigue-induced changes in guinea-pig diaphragmatic contractility.