title: Interactions between 1,2--propanediol (propylene glycol) and hexobarbital.
abstract: The interaction between 1,2--propanediol and hexobarbital was studied with an anaesthesia threshold method, where hexobarbital is infused intravenously. The dose needed to obtain a burst suppression of one second or more is determined and given as per cent of a pre-experimental value obtained in the same rat. The effect of varying the interval between the intraperitoneal injection of 1,2--propanediol (2.06 g/kg) and the threshold determination was investigated. In the intervals, 10--50 min., the hexobarbital threshold doses were significantly decreased by 13--27% (n = 7--18). Four different doses between 0.25 and 2.06 g/kg of 1,2--propanediol were then tested after a fixed interval of 30 min. As in the time interval study the thresholds after 2.06 g/kg were significantly decreased. No certain depressant effect was seen with 1.03 and 0.52 g/kg. With the lowest tested dose of 1,2-propanediol (0.25 g/kg) there was instead a significant increase in the threshold dose (13%). This might be an excitatory effect, which could correspond to the well-known effect, seen with low doses of other depressants for instance ethanol.
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects*; D004347:Drug Interactions; D006591:Hexobarbital / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D007274:Injections, Intraperitoneal; D007275:Injections, Intravenous; D008297:Male; D011409:Propylene Glycols / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D051381:Rats
chemical_list: D011409:Propylene Glycols; D006591:Hexobarbital