Brain adrenoceptor binding sites in mice susceptible (DBA/2J) and resistant (C57 Bl/6) to audiogenic seizures.
We have examined if the age-related susceptibility of DBA/2J mice to audiogenic seizures is the result of an abnormality in the number or sensitivity of brain adrenoceptors. The binding of alpha 1-, alpha 2-, and beta-adrenoceptor ligands to membranes prepared from whole brain or regions of brain of DBA/2J mice was measured at various ages, corresponding to the periods before, during, and after the maximal sensitivity to audiogenic seizures. For comparison, we have studied concurrently age-matched C57 Bl/6 mice, a strain resistant to audiogenic seizures at all ages. There was no difference in the binding of alpha 2- or beta-adrenoceptor ligands to whole brain membranes between the two strains of mice at any age. The maximal number of alpha 1-adrenoceptor binding sites was lower in whole brains of DBA/2J mice than of C57 Bl/6 mice at all ages studied except 13-15 days of age. The differences were small (maximally 17%) but were statistically significant at 21-23 days of age, the time of maximal sensitivity of DBA/2J mice to audiogenic seizures. No difference between the two strains was found in the number or affinity of alpha 1- or alpha 2-adrenoceptor binding sites at any age in any of the brain regions studied. The age-related susceptibility of DBA/2J mice to audiogenic seizures is not the result of an abnormality in number or sensitivity of alpha 2- or beta-adrenoceptor binding sites, but a reduced number of alpha 1-adrenoceptor binding sites may be involved.
S P
SP
Jazrawi
R W
RW
Horton
D000161:Acoustic Stimulation; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000378:metabolism*; D003000:Clonidine / Q000378:metabolism; D004082:Dihydroalprenolol / Q000378:metabolism; D004198:Disease Susceptibility; D008566:Membranes / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL / Q000235:genetics* / Q000378:metabolism; D008811:Mice, Inbred DBA / Q000235:genetics* / Q000378:metabolism; D011224:Prazosin / Q000378:metabolism; D011941:Receptors, Adrenergic / Q000378:metabolism*; D012640:Seizures / Q000235:genetics*; D014316:Tritium
D011941:Receptors, Adrenergic; D014316:Tritium; D004082:Dihydroalprenolol; D003000:Clonidine; D011224:Prazosin