链霉素降压机制的进一步研究

给乌拉坦麻醉家兔,静脉注射新斯的明,既不能防止也不能对链霉素的降压作用;在给予神经节阻断药(六烷双铵)后,链霉素的降压效应仍然表现.链霉素和二链霉胺均能抑制在位兔心的收缩作用.在脊髓大白鼠和脊髓猫标本上,链霉素仍有降压作用.链霉素在降低麻醉猫血压时,猫瞬膜对颈上交感神经节前纤维刺激的反应减弱.这些结果表明,链霉素的降压机制主要是由于对心脏的抑制作用和神经节的阻断作用.此外,链霉素的降压作用与其所含杂质二链霉胺有一定关系.

FURTHER STUDIES ON THE MECHANISM OF THE HYPOTENSIVE ACTION OF STREPTOMYCIN

In rabbits anaesthetized with urethane, intravenous injection of neostigmine neither prevented nor antagonized the hypotensive action of streptomycin. The hypotensive action still persisted after administration of the ganglion blocking agent, hexamethonium. The contraction of the rabbit heart in situ was depressed by streptomycin and bis-(α-hydroxy- streptomycyl)-amine. In the spinal rats and cats, streptomycin induced a fall in blood pressure. While streptomycin caused a fall of blood pressure in anaesthetized cat, the responses of the nictitating membrane to cervical superior sympathetic nerve preganglionic fibre were diminished. It is suggested that the mechanism of the hypotensive effect of streptomycin was chiefly due to the inhibitory effect on the heart and ganglion blocking action. Furthermore, the hypotensive mechanism of streptomycin was found to be partly related to bis-(α-hydroxystreptomycyl)-amine, a toxic derivative of streptomycin.