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Depression of ventilation by dopamine in cats: effects of bilateral cervical sympathetic and vagal trunk section
Author(s) -
Wypych B,
SzeredaPrzestaszewska M
Publication year - 1995
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/expphysiol.1995.sp003845
Subject(s) - vagotomy , anesthesia , cats , medicine , ventilation (architecture) , dopamine , carotid body , control of respiration , carotid sinus , respiratory system , tidal volume , reflex , stimulation , mechanical engineering , engineering
The contribution of sympathetic and vagal inputs to ventilatory depression induced by dopamine was studied in eighteen anaesthetized, spontaneously breathing, normoxic cats. Breathing was via a tracheostomy. Dopamine (20 micrograms (kg body wt)‐1) was injected intravenously in the intact animal, then after section of the cervical sympathetic trunks, and finally after midcervical vagotomy. Dopamine, injected as a bolus, induced depression of ventilation, affecting predominantly the volume component of the breathing pattern at all experimental stages. The extent of volume reduction was larger and different from that in intact animals following section of sympathetic (P < 0.05) and vagal trunks (P < 0.01). The respiratory cycle was significantly prolonged (P < 0.01) prior to vagotomy, due entirely to the increase in the expiratory time (TE). Bilateral section of the carotid sinus nerves performed in six cats virtually abolished postdopamine ventilatory depression.