A role of the autonomic nervous system in alterations of blood pressure and heart rate induced by 1, 1, 1-trichloroethane (author's transl)

An experiment was conducted to clarify effect of 1, 1, 1- trichloroethane (1, 1, 1-TCE) on blood pressure and heart rate, and to investigate the role of the autonomic nervous system in these responses. Adult mongrel dogs were anesthetized with sodium pentobarbital (25-30 mg/kg, i. v.) and the respiration was maintained artificially with positive pressure ventilation. Fifty mg/kg of 1, 1, 1-TCE was intravenously injected. The left kidney was exposed by flank incision, and discharges of efferent renal sympathetic nerve were recorded using bipolar platinum electrodes. 1, 1, 1-TCE induced 39.6 +/- 3.1% (mean +/- S. E.) diminution in systemic blood pressure compared to each pre-administration level, but the blood pressure gradually returned to the control level in the vagi intact group. A fall in blood pressure to 39.3 +/- 5.1% level was induced by 1, 1, 1-TCE in the group which had been bilaterally vagotomized or treated with atropine, but it was not significantly different from that in the vagi intact group. Immediately after the administration of 1, 1, 1-TCE, heart rate significantly decreased from 122, 3 +/- 9.1 to 86 +/- 5.6 beats/min in the vagi intact group, but remained unchanged in the vagotomy or atropine group. Discharges...Continue Reading