Abstract
The mechanism of action of the antipyretic drugs has been discussed from the point of view based mainly on the hypothalamic thermoregulatory center. Since the introduction of Mayer's classical theory (1), many authors (2-6) have attributed the site of action of the drugs to the hypothalamus and other basal nuclei from their extensive studies. In the previous paper the author has studied on the effects of aminopyrine on the electroencephalogram in cats (7). The results that the manifestation of the seizure discharge of the spontaneous EEG in cat in response to aminopyrine was preceded by the manifestation of the seizure discharge or spike waves of the hypothalamic and thalamic EEG have suggested the primary site of action of aminopyrine on the diffuse region of the anterior hypothalamus.
However, the electrophysiological studies of aminopyrine by Fujita et al. (8, 9) have shown the diffuse dimensions of the site of action within the brain. The effects of aminopyrine shown by the authors, according to the general consideration, may include various aspects of the drug effects such as analgesic, antipyretic and other side effects as well as the secondary or rebound effects. In the current report attempts were made to differentiate the unique antipyretic effect of aminopyrine from the other effects either dependent or independent on the antipyresis by comparing the time course of the EEG changes.
Moreover, the effects of aminopyrine on the EEG were also studied in the rabbit which had received the pyretic doses of 2, 4-dinitrophenol.
