静注强力霉素引起心血管效应的作用部位分析

强力霉素是人工半合成四环素类抗菌素之一,兽医临床常用速度静注时,血浓度达到一定水平(低于治疗浓度)则对马、骡、驴能迅速引起急性甚至是致死性虚脱反应。至今国外尚无报道。本文分析了强力霉素引起心血管效应的主要作用部位。通过对14头驴心电图描记,可看出初期心脏频率变慢,房室传导阻滞及室前早搏;对5只麻醉犬血压、呼吸的22次描记中有明显降压反应;对3只离体兔心的15次描记有明显抑制作用。并通过5只犬15次关于降压作用与植物性神经系统的实验及对3只兔9次给药的血管灌流实验,我们认为,强力霉素引起心血管效应的主要部位是在中枢神经系统和心脏。而中枢作用很可能是通过迷走神经影响心脏和其它部位活动的。虚脱发生后出现的心动过速,可能由机体的代偿功能所致。这些效应与α—受体、β—受体部位无关。

Analysis on the Affected Parts of the Heart Blood Vessel Effects Caused by the Intravenous Injection of Doxycycline

Doxycycline, one of the antibiotics, is a kind of half-synthetic tetrabiotic drugs, which will immediately Cause an acute or even lethal collapse to horses, mules or donkeys whenever it is clinically used in the intravenous injection to animals at the common speed with the blood concentration reaching a given level (lower than that of treatment)up to now. There haven't been any reports about this abroad. Analysis of the main affected parts of the heart-blood vessel effects due to the Doxycycline are shown in the paper. By the observation and records of ECG to fourteen donkeys, we can see an auriculoventricular block and premature beat as well as a slow-down of the frequencies of heart beat during the initial stage. There appears the obvious depressive reaction of blood pressure in twenty-two traces of blood pressure and breath of five anesthetic dogs and an evident depressive effects after the observation and records for 15 times to three isolated hearts of rabbit. Based on fifteen experiments on six dogs with the pressive reaction of blood pressure and vegetative nervous system and on nine tests on three rabbits with prefusive blood vessel with medicine, we thought that the major seat of the action of IV administration of doxycycline inducing cardiovascular effects was both, the cen- tral nervous system and the heart. And it was possible for the central nerves to have influenced the heart and other parts through vagus nerve. So, the heart's speeding up after the collapse was probably caused by the organism's function of compensation. The effccts have no relation with the places of α-and β-receptors.