Regional changes in [3H]inositol 1,4,5-triphosphate binding in the gerbil brain following repeated sublethal ischemia.
We investigated the regional changes in [3H]inositol 1,4,5-triphosphate (IP3) binding in the brain following ischemia using in vitro autoradiography. Three 2-min ischemic insults at 1-hr intervals and a 6-min period of ischemia were induced in gerbils and they were killed after 1, 4, and 28 days. Normal animals had high [3H]IP3 binding in the CA1 subfield of the hippocampus and the striatum. The binding in the CA1 decreased strikingly after both 6-min ischemia and three 2-min ischemic insults. The [3H]IP3 binding also decreased in the lateral striatum after three 2-min ischemic insults but not after 6 min of ischemia. Histological observations confirmed neuronal damage to these areas of reduced binding. By contrast, we found a marked increase in [3H]IP3 binding in the ventral thalamus 28 days after three 2-min ischemic insults. Histological observations with Nissl staining revealed an accumulation of fine granular deposits there. Thus, repeated ischemic insults produced more extensive neuronal damage and changes in [3H]IP3 binding than a single equivalent period of ischemia. The increased [3H]IP3 binding in the thalamus coincidentally with an accumulation of Nissl-positive granules at the chronic stage after repeated ischemia is of considerable interest.
Kato
H
H
Department of Neurology, Tohoku University School of Medicine, Sendai, Japan.
Araki
T
T
Hara
H
H
Kogure
K
K
D000818:Animals; D001345:Autoradiography; D001923:Brain Chemistry / Q000502:physiology*; D002545:Brain Ischemia / Q000378:metabolism*; D005849:Gerbillinae; D006624:Hippocampus / Q000378:metabolism; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D008297:Male; D017072:Neostriatum / Q000378:metabolism; D013788:Thalamus / Q000378:metabolism
D015544:Inositol 1,4,5-Trisphosphate