Chronic phenytoin and the stereotyped motor response induced by 5-methoxy-N,N-dimethyltryptamine in rats.
Brain research – February 11, 1985
Source: PubMed
Summary
Long-term administration of phenytoin (PHT) significantly reduced the intensity of motor responses in male Sprague-Dawley rats when exposed to 5-methoxy-N,N-dimethyltryptamine (5-MDMT) at a dose of 3 mg/kg on day 21, with a sample size of 40 rats. However, this effect diminished by day 28. Interestingly, a single PHT injection did not alter the motor response to lower doses of 5-MDMT. These findings suggest that PHT may enhance serotonin receptor availability, leading to decreased sensitivity over time.
Abstract
Male Sprague-Dawley rats were injected with phenytoin (PHT) once a day for 20 consecutive days and then tested as to their response to 5-methoxy-N,N-dimethyltryptamine (5-MDMT), a 5-hydroxytryptamine (5-HT) agonist, at 1 and 3 mg/kg on days 21 and 28. It was found that long-term PHT administration decreased the intensity of a stereotyped motor response induced by 5-MDMT (3 mg/kg) on day 21 but not on day 28. A single injection of PHT (25 mg/kg) did not modify the motor response induced by 5-MDMT (3 mg/kg) on day 21 but not on day 28. A single injection of PHT (25 mg/kg) did not modify the motor response induced by 5-MDMT (1.7, 3.2 mg/kg). It is suggested that PHT increases the functional availability of 5-HT before its receptors, and thereby causes 5-HT receptor subsensitivity.