AIM To investigate the pathways of Ca 2+ entry into ECV304 endothelial cell and the effect of angiotensin Ⅱ(AⅡ) on calcium activated non setective cation channel(CAN). METHODS The cell attachment and whole cell configurations of patch clamp technique were used to record channel activity. RESULTS (1) The single channel conductance is ? o=(12 90?2 11) pS( n =4) for Ca 2+ passing through CAN of ECV304 cell in condition of pipette solution without K + and Na + but composed 120 mmol?L -1 CaCl 2. The channel current amplitude and open time can be enhanced by 1?10 -7 mol?L -1 AⅡ. The enhanced conductance in CAN is ? 1=(22 18?2 29) pS( n =4). The results of whole cell recording are identified with single channel recording. (2) The whole cell configuration was carried out for recording voltage dependent Ca 2+ channel in ECV304 cell. The peak current amplitude was (29 32?3 56) pA( n =4). This current was inhibited to (6 00?3 94) pA( n =4) by nifedipine and activated by BayK8644. CONCLUSIONS (1)Ca 2+ enters ECV304 cell via Ca 2+ activated non selective cation channel and voltage dependent L type calcium channel. (2) AⅡ can significantly enhance the calcium entry via CAN in ECV304 cell.

Objective : To investigate the correlation between obstructive sleep apnea hypopnea syndrome (OSAHS ) and hypertension and its risk factors ,so as to provide basis for prevention and treatment of OSAHS accompanied by hypertension . Methods : A total of 108 OSAHS patients were enrolled and the general conditions were recorded . The blood pressure at 22 ∶ 00 before sleep and that at 8 ∶ 00 . next morning was determined routinely ,and the blood lipid level was detected . According to apnea hypoapnea index (AHI) ,the patients were divided into three groups ,the mild group (5/h ≤ AHI < 15/h) with 31 cases ,the moderate group (15/h ≤ AHI < 40/h) with 36 cases ,and the severe group (AHI ≥ 40 /h) with 41 cases . The levels of blood pressure were compared among the groups . According to whether OSAHS was accompanied by hypertension ,the patients were divided into simple OSAHS group and OSAHS accompanied by hypertension group . The relevant factors associated with OSAHS accompanied by hypertension were screened out by single factor analysis ,and then the multiple Logistic regression analysis was conducted .Results : (1)Among 108 patients with OSAHS ,60 cases(55 .6% ) were accompanied by hypertension ,including 15 cases of mild group(48 .4% ,15/31) ,19 cases of moderate group (52 .8% ,19/36) ,and 26 cases of severe group (63 .4% ,26/41 ) . There was no significant difference regarding the prevalence rate of hypertension among the three groups (P > 0 .05) .There were significant differences regarding systolic blood pressure(SBP) and diastolic blood pressure (DBP) at 22 ∶ 00 and 8 ∶ 00 among the three groups (P < 0 .05) ;SBP and DBP at 22 ∶ 00 and 8 ∶ 00 in severe group were significantly higher than those in mild group (P< 0 .05) .SBP at 22 ∶ 00 and 8 ∶ 00 in severe group was significantly higher than that in moderate group (P< 0 .05) .(2) Single factor analysis showed that age ,body mass index (BMI) ,smoking rate ,abdominal circumference ,AHI ,total cholesterol(TC) ,triglyceride(TG ) and low density lipoprotein cholesterol (LDL-C) in OSAHS accompanied by hypertension group were significantly higher than those in simple OSAHS group ,while HDL-C was significantly lower than that in simple OSAHS group ( P < 0 .05 ) . (3 ) Multivariate Logistic regression analysis showed that BMI ,AHI ,TC were the risk factors for OSAHS accompanied by hypertension .Conclusions :The level of blood pressure in patients with OSAHS was accordance with the disease severity ,while BMI ,AHI ,TC were the risk factors for OSAHS accompanied by hypertension .