ABSTRACT
To investigate the effect of sea anemone toxin anthopleurin-Q (AP-Q) on potassium currents in isolated rats and guinea pig ventricular myocytes.Methods The ventricular cells of guinea pigs and SD rats were obtained by enzymatic dissociation method.Whole cell patch clamp technique was used to record potassium currents (Ito,IK,and IK1).Results AP-Q 3-100 nmol/L increased Ito in a concentration-dependent manner,with an EC50 value of 12.7 nmol/L.At a potential of +50mV,AP-Q 10nmol/L increased Ito from (13.3±3.4) pA pF-1 to (19.46±4.3) pA pF-1.AP-Q 0.1-100 nmol/L increased IK and IK tail in a concentration-dependent manner with EC50 values of 4.7 nmol/L and 5.0 nmol/L,respectively.AP-Q 1 pmol/L-100 nmol/L increased IK1 in dose-dependent manner,with an EC50 of 0.2 nmol/L.Conclusions The effect of AP-Q on Ito,IK and IK1 may partly explain its mechanism in shortening APD and increasing RP.(J Geriatr Cardiol 2008;5:243-247)
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the risk factors for peripheral arterial disease (PAD) and the relationship of low ankle brachial index (ABI) to all-cause and cardiovascular disease (CVD) mortality in Chinese male patients with hypertension.</p><p><b>METHODS</b>The data of 1606 male participants with hypertension from the eight hospitals in Beijing and Shanghai were analyzed. ABI was ascertained at baseline by measuring the systolic pressures on bilateral brachial and tibial arteries. ABI < or = 0.9 was used as the diagnostic criteria for PAD identification. The follow-up survey was conducted from November 2005 to January 2006.</p><p><b>RESULTS</b>Of 1606 male participants with hypertension at baseline, 406 (25.3% ) were in low-ABI group and 1200 (74.7%) were in normal-ABI group. Older age, TC, history of diabetes, history of smoking and 2-grade hypertension were associated with low ABI in male patients with hypertension. During the (12.87 +/- 2.94) months follow-up, there were 153 deaths. Of which, 62 were attributable to CVD. Low ABI was associated with adjusted all-cause and CVD mortality risk of 1.728 (1.223-2.441) and 2.388 (1.409-4.046) respectively in Cox regression models. Rate of survival for the low-ABI group was significantly worse than for the normal-ABI group. The risk of all-cause and CVD mortality was increased with the decline of ABI.</p><p><b>CONCLUSION</b>Low ABI is independently associated with the high risks of all-cause and CVD mortality in Chinese male patients with hypertension. The utility of ABI as a tool for predicting mortality in the patients with hypertension should be popularized.</p>