It was the aim of this investigation to find out why pentetrazol (PTZ) administered orally to rats has considerably lower convulsive effectiveness than PTZ injected parenterally. It could be demonstrated that PTZ is distributed to and eliminated from all organs analyzed, without any sign of storage or of redistribution. Biological halftime was found to be about 3.5 h after subcutaneous injection. PTZ is absorbed slowly from the gastrointestinal tract because PTZ given orally is retained in the stomach for many hours. PTZ absorption is slow from the stomach while it is rapid from the small intestine. Food taken in before and after PTZ administration decreases the rate of PTZ absorption. Retention in the stomach of PTZ given orally is probably due to delayed gastric emptying since PTZ is able to reduce the basal tone and the acetylcholine-induced contractions of isolated preparations of the fundus of the stomach.
1. Whole-body autoradiographic evidence that alpha-1,2,3,4,5,6-hexachlorocyclohexane (alpha-HCH), a racemic compound with anticonvulsant and tremorogenic activities, accumulates in cerebral white over grey matter was confirmed in rats using unlabelled compound and g.l.c. determination in tissue samples. 2. Accumulation in, and retention by, cerebral white matter after a small intravenous dose was in marked excess of what may be accounted for by solvation and was due solely to the (+)-enantiomer. 3. Similar behaviour was exhibited by the (3,6/4,5)-isomers of 1,3,4,5,6-pentachlorocyclohex-1-ene (PCCH) and 1,2,3,4,5,6-hexachlorocyclohex-1-ene (HCCH) but not by other isomers of HCH, HCCH and PCCH suggesting that stereoselective binding to, presumably, some constituent of myelin might depend on the presence of a vicinal pair of (semi)-axially oriented carbon-chlorine bonds. 4. Evidence is presented which indicates that the anti-convulsant and tremorogenic effects of alpha-HCH are unlikely to be related to this property.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.