Objective To explore the activity of Ca2 + -activated K+ ( KCa) inairwaysmoothmuscle cells( ASMCs) in a rat model of chronic obstructive pulmonary disease( COPD) , and to observe the effect of 11, 12-Epoxyeicosatrienoic acid( 11, 12-EETs) on the KCa channel of ASMCs. Methods Forty male Sprague-Dawley rats were randomly assigned to a COPD group and a normal control group. The rats in the COPD group were exposed to cigarette smoking in a relatively closed chamber to induce COPD. The ASMCs were isolated from small bronchi using an acute enzymatic digestion method. In the symmetrical high K+ solution,the KCa currents were separated with inside-out configuration using the patch clamp technique. The activity of KCa currents in ASMCs between the COPD group and the normal group were compared and the effect of 11, 12-EETs on KCa channel was recorded. The opening probability( Po) , opening time( To) and closing time ( Tc) of the KCa were measured. Results Compared with the normal group, Po of KCa in the COPD rats was much shorter ( 0. 084 ±0. 028 vs 0. 198 ±0. 029, P lt; 0. 01) , To was shorter [ ( 0. 732 ±0. 058) ms vs ( 1. 648 ±0. 152) ms, P lt; 0. 01] and Tc was longer[ ( 12. 259 ±2. 612) ms vs ( 6. 753 ±1. 237) ms, P lt;0. 01] . 11, 12-EETs can evoke the activity of KCa currents of ASMCs in the COPD rats while Po was increased( 0. 227 ±0. 059 vs 0. 084 ±0. 028, P lt; 0. 01) , To was much longer[ ( 2. 068 ±0. 064) ms vs ( 0. 732 ±0. 058) ms, P lt; 0. 01] , and Tc was shorter [ ( 4. 273 ±0. 978) ms vs ( 12. 259 ±2. 612) ms, P lt;0. 01] .Conclusions The results suggest that the decreasing of KCa activity plays an important role in the development of COPD. 11,12-EETs can directly evoke the activity of KCa channel in COPD rats, thus relax the airway smooth muscles.
ObjectiveTo summarize research progress of vascular physiological function of epoxyeicosatrienoic acid and its impact on pathogenesis of cirrhotic portal hypertension. MethodLiteratures about recent studies on epoxyeicosatrienoic acid in different organs and different animal models including cirrhotic portal hypertension were reviewed according to the results searched from PubMed and Wanfang databases. ResultsEpoxyeicosatrienoic acid in the different organs and the different animal models showed the complex functions, and it might affect the development of cirrhosis portal hypertension disease through its vascular physiological function. ConclusionIncreasing or decreasing epoxyeicosatrienoic acid might affect development of cirrhosis portal hypertension disease, which could provide a new method for treatment of cirrhosis portal hypertension.