Petery L B, Van Mierop L H
Am J Physiol. 1977 Mar;232(3):H250-4. doi: 10.1152/ajpheart.1977.232.3.H250.
Effects of sympathomimetic amines without and with alpha and beta-adrenergic blocking agents on the heart rate and arterial and venous blood pressures in the 3-day-old chick embryo were studied. No chronotropic effect was observed. Norepinephrine caused a biphasic change in systolic and diastolic arterial pressures, the lower doses effecting a fall, and the higher doses a rise in these pressures. With phenylephrine a sharp rise in systolic, diastolic, and pulse pressures was seen. Isoproterenol caused a dramatic fall in systolic, diastolic, and pulse pressures. In the presence of phenoxybenzamine, the pressor effect of high doses of norepinephrine was reversed, the pressor effect of phenylephrine was abolished, and the hypotension with isoproterenol was enhanced. After propranolol, the hypotensive effect of low doses of norepinephrine was reversed, the pressor response to phenylephrine was unchanged, and the depressor effect of isoproterenol was abolished. These findings suggest the presence of functioning alpha- and beta-receptors in the 3-day-old chick embryo. Additionally, they suggest that the alpha-receptors develop more slowly in the chick embryo.
研究了拟交感胺在有无α和β肾上腺素能阻滞剂情况下对3日龄鸡胚心率以及动脉和静脉血压的影响。未观察到变时效应。去甲肾上腺素使收缩压和舒张压出现双相变化，较低剂量导致血压下降，较高剂量则使血压升高。使用去氧肾上腺素时，收缩压、舒张压和脉压急剧升高。异丙肾上腺素导致收缩压、舒张压和脉压显著下降。在存在酚苄明的情况下，高剂量去甲肾上腺素的升压作用被逆转，去氧肾上腺素的升压作用被消除，而异丙肾上腺素引起的低血压则增强。使用普萘洛尔后，低剂量去甲肾上腺素的降压作用被逆转，对去氧肾上腺素的升压反应未改变，而异丙肾上腺素的降压作用被消除。这些发现表明3日龄鸡胚中存在有功能的α和β受体。此外，还表明α受体在鸡胚中发育较慢。
