European journal of clinical investigation · 2000
Effects of phospholipase A2, free fatty acids and 2-lysolecithin on the crystallization of cholesterol in gallbladder bile.
СтатьяПоддержка исследования: вне правительства СШАНазвание и аннотация: Перевод пока не подготовлен
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Schöne A, Jüngst D, Meyer G, Hernandez-Richter T, Fischer S
Аннотация
BACKGROUND: Phospholipase A2 (PLA2) and its enzymatic products free fatty acids (FFAs) and 2-lysolecithin are physiological constituents of bile. Their role in the crystallization of cholesterol in gallbladder bile of patients with cholesterol gallstones is still controversial.
DESIGN: To clarify this issue we evaluated the activity of PLA2 and the concentration and pattern of FFAs in the gallbladder bile of cholesterol stone patients. We furthermore added PLA2, FFAs and 2-lysolecithin to isotropic gallbladder bile, determined the crystal observation time (COT) and counted the cholesterol crystals in a crystal growth assay for up to 21 days.
RESULTS: A PLA2 activity of 1.8 +/- 1.2 U L(-1) and total FFA concentrations of 1.32 +/- 0.71 mmol L(-1) were determined. After incubation of bile for 24 h at 37 degrees C total FFAs increased to 2.72 +/- 1.29 mmol L(-1) (P<0.005). Biliary saturated and unsaturated FFAs were found in equal proportions before and after incubation, pointing to an additional presence of lipases other than PLA2. A COTof 1 day was observed in all gallbladder biles and increased to 1.7 +/- 0.5 days after addition of 5 U L(-1) of PLA2 (P<0.01). An even higher COT of 2.5 +/- 0.8 days was seen after addition of 5 mmol L(-1) of a 'biliary' mixture of FFAs (P<0.005) but the COT remained unchanged after addition of 5 mmol L(-1) of 2-lysolecithin. However, in the crystal growth assay in gallbladder bile addition of 5 U L(-1) of PLA2, of 5 mmol L(-1) of 'biliary' FFAs and of 5 mmol L(-1) of 2-lysolecithin decreased significantly the number of cholesterol crystals formed during follow-up.
CONCLUSION: An elevated activity of PLA2 in gallbladder bile may counteract the formation of cholesterol crystals through increased formation of FFAs and 2-lysolecithin. However, regarding the comparatively low activity of PLA2 in gallbladder bile PLA2 seems to be of only minor pathophysiological importance in the formation of cholesterol gallstones.
DESIGN: To clarify this issue we evaluated the activity of PLA2 and the concentration and pattern of FFAs in the gallbladder bile of cholesterol stone patients. We furthermore added PLA2, FFAs and 2-lysolecithin to isotropic gallbladder bile, determined the crystal observation time (COT) and counted the cholesterol crystals in a crystal growth assay for up to 21 days.
RESULTS: A PLA2 activity of 1.8 +/- 1.2 U L(-1) and total FFA concentrations of 1.32 +/- 0.71 mmol L(-1) were determined. After incubation of bile for 24 h at 37 degrees C total FFAs increased to 2.72 +/- 1.29 mmol L(-1) (P<0.005). Biliary saturated and unsaturated FFAs were found in equal proportions before and after incubation, pointing to an additional presence of lipases other than PLA2. A COTof 1 day was observed in all gallbladder biles and increased to 1.7 +/- 0.5 days after addition of 5 U L(-1) of PLA2 (P<0.01). An even higher COT of 2.5 +/- 0.8 days was seen after addition of 5 mmol L(-1) of a 'biliary' mixture of FFAs (P<0.005) but the COT remained unchanged after addition of 5 mmol L(-1) of 2-lysolecithin. However, in the crystal growth assay in gallbladder bile addition of 5 U L(-1) of PLA2, of 5 mmol L(-1) of 'biliary' FFAs and of 5 mmol L(-1) of 2-lysolecithin decreased significantly the number of cholesterol crystals formed during follow-up.
CONCLUSION: An elevated activity of PLA2 in gallbladder bile may counteract the formation of cholesterol crystals through increased formation of FFAs and 2-lysolecithin. However, regarding the comparatively low activity of PLA2 in gallbladder bile PLA2 seems to be of only minor pathophysiological importance in the formation of cholesterol gallstones.