Rosaeg O P, Cicutti N J, Labow R S
Department of Anesthesia, Ottawa Civic Hospital, Ontario, Canada.
Anesth Analg. 1998 Jan;86(1):40-4. doi: 10.1097/00000539-199801000-00008.
We performed an in vitro examination of the inotropic effect of oxytocin, chlorobutanol, and their combination to assess the effect of these drugs on the contractile force of human atrial trabeculae. Right atrial tissue samples were obtained during cardiac surgery with cardiopulmonary bypass. Trabeculae of the atrial appendage were dissected and mounted on muscle stands in a modified Krebs-Henseleit buffer bath. This isometric atrial trabecula preparation was subjected to a cumulative pharmacological protocol of either pure oxytocin, pure chlorobutanol, or a combination of the two drugs until no further change occurred in either developed force or resting force of the atrial trabeculae. A "no drug" buffer solution was used to assess the effect of time on the natural decay of the atrial preparation. The relative developed force of oxytocin plus chlorobutanol solution and pure chlorobutanol were similar in magnitude and lower than that in control experiments (P < 0.001) Pure oxytocin did not change the contractile force of atrial tissue. We conclude that pure oxytocin does not have a cardiodepressive effect in this human atrial preparation. Chlorobutanol has a negative inotropic effect, which is of a magnitude similar to a combined solution of chlorobutanol and oxytocin. Therefore, chlorobutanol added as a preservative to the commercial synthetic oxytocin solution may contribute to hypotension observed in patients after an intravenous bolus injection.
We obtained specimens of heart tissue from patients undergoing cardiac surgery and conducted a laboratory study of the effects of oxytocin and its preservative (chlorobutanol) on these tissue samples. Chlorobutanol decreased the ability of the heart to contract, while as pure oxytocin had no effect. This explains why maternal blood pressure may decrease and provides impetus to produce oxytocin with another, safer preservative.
我们对催产素、三氯叔丁醇及其组合的变力作用进行了体外检查，以评估这些药物对人房小梁收缩力的影响。右心房组织样本在体外循环心脏手术期间获取。心房附件的小梁被解剖并安装在改良的克雷布斯 - 亨塞尔特缓冲液浴中的肌肉支架上。将这种等长心房小梁制备物按照累积药理学方案给予纯催产素、纯三氯叔丁醇或两种药物的组合，直到心房小梁的舒张期力或静息力不再发生进一步变化。使用“无药物”缓冲溶液来评估时间对心房制备物自然衰退的影响。催产素加三氯叔丁醇溶液和纯三氯叔丁醇的相对舒张期力在大小上相似且低于对照实验中的值（P < 0.001）。纯催产素未改变心房组织的收缩力。我们得出结论，在这种人心房制备物中，纯催产素没有心脏抑制作用。三氯叔丁醇具有负性变力作用，其大小与三氯叔丁醇和催产素的组合溶液相似。因此，作为防腐剂添加到商业合成催产素溶液中的三氯叔丁醇可能是导致静脉推注后患者出现低血压的原因。
我们从接受心脏手术的患者身上获取心脏组织标本，并对催产素及其防腐剂（三氯叔丁醇）对这些组织样本的影响进行了实验室研究。三氯叔丁醇降低了心脏的收缩能力，而纯催产素没有影响。这解释了为什么产妇血压可能会下降，并为使用另一种更安全的防腐剂生产催产素提供了动力。
