Arishima K, Takizawa T, Oda T, Yamamoto M, Togashi H, Somiya H, Eguchi Y
Department of Anatomy II, Azabu University School of Veterinary Medicine, Kanagawa, Japan.
J Vet Med Sci. 1995 Oct;57(5):943-4. doi: 10.1292/jvms.57.943.
Newborn rats delivered by cesarean section were given subcutaneously propranolol (PRO), a beta-adrenergic blocker, (1) immediately or (2) 180 min after delivery. The diameter of the ductus arteriosus (DA) of the newborn pups was calibrated at 30, 60 and 90 min after the PRO-administration. The results were as follows: (1) the DA calibers of the pups given 0.2, 1.0., 5.0 mg/kg PRO immediately after cesarean delivery remained significantly larger than those of controls in a dose-dependent manner for 30 min after treatment. In the 5 mg/kg group, the enlargement of the DA was prolonged for 90 min after treatment. (2) In untreated pups, the DA completely closed by 180 min after cesarean delivery. The DA was not affected by the administration of 5 mg/kg PRO at 3 hr after delivery. It was concluded that, PRO inhibits the spontaneous constriction of the DA, suggesting an important role of beta-adrenergic stimulation on the spontaneous closure of the DA in newborn rats.
通过剖宫产分娩的新生大鼠，在产后（1）立即或（2）180分钟皮下注射β-肾上腺素能阻滞剂普萘洛尔（PRO）。在给予PRO后30、60和90分钟测量新生幼崽动脉导管（DA）的直径。结果如下：（1）剖宫产术后立即给予0.2、1.0、5.0mg/kg PRO的幼崽，其DA管径在治疗后30分钟内以剂量依赖方式显著大于对照组。在5mg/kg组中，治疗后DA的扩张延长至90分钟。（2）未经治疗的幼崽，剖宫产术后180分钟DA完全闭合。产后3小时给予5mg/kg PRO对DA无影响。结论是，PRO抑制DA的自发性收缩，提示β-肾上腺素能刺激在新生大鼠DA自发性闭合中起重要作用。
