Electrophysiological study of infant and adult rats under acute intoxication with fluoroacetamide.
A study was conducted of acute intoxication of infant and adult Wistar rats with fluoroacetamide (FAA), an inhibitor of oxidative metabolism. FAA was administered orally to adult rats at 1/2 LD(50) and subcutaneously to infant rats at LD(100) or 1/10 LD(50). Electrocardiogram (ECG), respiration and motor activity were registered for 7 days. Clinical analysis of ECG and the heart rate variability (HRV) was carried out to assess the state of the vegetative nervous system. In adult rats, FAA caused marked disturbances in the activity of cardiovascular and respiratory systems, including the development of a potentially lethal acute cor pulmonale. Conversely, there were no significant changes of cardiac function and respiration in infant rats; they died because of extreme emaciation accompanied by retardation of development. In adult rats, bursts of associated cardiac and respiratory tachyarrhythmia, as well as regular high amplitude spasmodic sighs having a deca-second rhythm were observed. In both infant and adult rats, FAA caused short-term enhancement of humoral (metabolic) and sympathetic activities, followed by a gradual and stable predominance of parasympathetic influence on HRV. Under conditions of FAA inhibition of the tricarboxylic acid cycle, the observed physiological reactions may be explained by activation of alternative metabolic pathways. This is also supported by a lack of ontogenetically caused inhibition of spontaneous motor activity in infant rats poisoned with FAA, which highlights the significance of the alternative metabolic pathways for implementation of deca-second and minute rhythms and a lack of a rigid dependence of these rhythms upon activity of neuronal networks.
Kuznetsov
Sergey V
SV
I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, St Petersburg, Russia.
Jenkins
Richard O
RO
Goncharov
Nikolay V
NV
D000208:Acute Disease; D000284:Administration, Oral; D000367:Age Factors; D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D001145:Arrhythmias, Cardiac / Q000139:chemically induced / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography; D004734:Energy Metabolism / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000633:toxicity*; D005463:Fluoroacetates / Q000008:administration & dosage / Q000633:toxicity*; D006321:Heart / Q000187:drug effects* / Q000294:innervation; D006339:Heart Rate / Q000187:drug effects*; D007279:Injections, Subcutaneous; D009043:Motor Activity / Q000187:drug effects*; D010275:Parasympathetic Nervous System / Q000187:drug effects / Q000503:physiopathology; D011660:Pulmonary Heart Disease / Q000139:chemically induced / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar; D012119:Respiration / Q000187:drug effects*; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000503:physiopathology; D013997:Time Factors; D023382:Toxicity Tests, Acute
D004791:Enzyme Inhibitors; D005463:Fluoroacetates; C007741:fluoroacetamide