Irradiation of the head by 60Co opens the blood-brain barrier for drugs in rats.
The passage of 6 model drugs; acetylsalicylic acid, chloramphenicol, ethimizol, carbisocaine, heptacaine, and diazepam, through the blood-brain barrier, was determined in unirradiated control rats and in animals 1, 3, and 7 days after irradiation of the head only with a dose of 25 Gy from a 60Co source. The brain uptake index (BUI), which compares the uptake of the test substance with that of 3H2O 5 s after their injection into the common carotid artery, was significantly increased in comparison with unirradiated controls 7 days after irradiation, for all substances tested except for ethimizol. For acetylsalicylic acid and chloramphenicol it was also significantly increased in the other time intervals. The less lipophilic substances showed a greater relative increase of BUI than the more lipophilic ones.
Bezek
S
S
Institute of Experimental Pharmacology, Slovak Academy of Sciences, Bratislava, Czechoslovakia.
Trnovec
T
T
Scasnár
V
V
Durisová
M
M
Kukan
M
M
Kállay
Z
Z
Laginová
V
V
Svoboda
V
V
D000818:Animals; D001241:Aspirin / Q000493:pharmacokinetics; D001812:Blood-Brain Barrier / Q000528:radiation effects*; D001921:Brain / Q000378:metabolism; D002219:Carbamates / Q000493:pharmacokinetics; D002701:Chloramphenicol / Q000493:pharmacokinetics; D003037:Cobalt Radioisotopes; D016371:Cranial Irradiation; D003975:Diazepam / Q000493:pharmacokinetics; D005042:Etimizol / Q000493:pharmacokinetics; D008297:Male; D010880:Piperidines / Q000493:pharmacokinetics; D051381:Rats; D011919:Rats, Inbred Strains; D012044:Regression Analysis
D002219:Carbamates; D003037:Cobalt Radioisotopes; D010880:Piperidines; C013549:heptacaine; D002701:Chloramphenicol; C046030:carbizocaine; D005042:Etimizol; D003975:Diazepam; D001241:Aspirin