Headley S A, Moser C D, Golan R, Kendrick Z V, Finck A, Paolone A M
Department of Physical Education, Springfield College, Allied Health Science Center, MA 01109, USA.
Can J Physiol Pharmacol. 1996 Jan;74(1):112-5.
To determine the cardiovascular responses to beta-blockade and cold air stress, six males were randomly exposed at rest to three drug conditions (placebo, nonselective beta-blockade (propranolol), and selective beta-blockade (atenolol)) in each of two environments (5 and 25 degrees C) for 1 h. Cardiac output was lower on beta-blockade than on the placebo in both the 25 and 5 degrees C environments. Cardiac output on propranolol (4.2 +/- 0.3 L.min-1) at 5 degrees C was lower than on atenolol (4.7 +/- 0.4 L.min-1, p < 0.05). Mean arterial pressure was greater (p < 0.05) at 5 than 25 degrees C for each drug condition. There was no drug effect on total peripheral resistance at 25 degrees C. At 5 degrees C, total peripheral resistance on both beta-blockers (propranolol 1942.7 +/- 169.9 dyn.s.cm-5 (1 dyn = 10 microN); atenolol 1706.7 +/- 160.0 dyn.s.cm-5) was higher (p < 0.05) than on the placebo (1485.3 +/- 111.8 dyn.s.cm-5). Total peripheral resistance was also higher on propranolol than atenolol (p < 0.05). In conclusion, cold air stress interacts with beta-blockade to elevate total peripheral resistance by decreasing cardiac output while having little effect on mean arterial pressure. These effects are greater on nonselective than on selective blockade.
为了确定β受体阻滞剂和冷空气应激对心血管系统的影响，六名男性在静息状态下被随机暴露于两种环境温度（5℃和25℃）中的三种药物条件下（安慰剂、非选择性β受体阻滞剂（普萘洛尔）和选择性β受体阻滞剂（阿替洛尔）），每种条件持续1小时。在25℃和5℃环境中，使用β受体阻滞剂时的心输出量均低于使用安慰剂时。在5℃时，使用普萘洛尔时的心输出量（4.2±0.3L·min⁻¹）低于使用阿替洛尔时（4.7±0.4L·min⁻¹，p<0.05）。在每种药物条件下，5℃时的平均动脉压均高于25℃时（p<0.05）。在25℃时，药物对总外周阻力没有影响。在5℃时，两种β受体阻滞剂（普萘洛尔1942.7±169.9dyn·s·cm⁻⁵（1dyn = 10μN）；阿替洛尔1706.7±160.0dyn·s·cm⁻⁵）时的总外周阻力均高于安慰剂（1485.3±111.8dyn·s·cm⁻⁵）（p<0.05）。普萘洛尔时的总外周阻力也高于阿替洛尔（p<0.05）。总之，冷空气应激与β受体阻滞剂相互作用，通过降低心输出量来升高总外周阻力，而对平均动脉压影响较小。这些影响在非选择性阻滞时比选择性阻滞时更大。
