Uptake kinetics and receptor binding of glucocorticosteroids in head injury: an experimental study in a rat brain oedema model.
The uptake of dexamethasone (DM), as well as the glucocorticoid receptors binding sites (GCR) were studied in normal rat brain and in the rat brain after cold lesion of the right hemisphere. DM was taken up at a rate of 5.05 nmol/mg prot./min. by isolated cells of normal brain. This uptake was concentration (saturation at 10(-4) DM) and time dependent (linear up to 10 min), but was not temperature dependent. Isolated cells derived from the cold lesioned brain demonstrated a process, which is unsaturable (diffusion like) and not time nor temperature dependent. The brains of adrenalectomized rats were assayed for the GCR. There was no marked difference in the GCR content of the cortex, white matter and brain stem. Within 6 h after the cold lesion the GCR concentration in the lesioned hemisphere increased significantly (p less than 0.05). This increase was followed by a slow-levelling-off within 2 days, to reach the control values again in 7 days. At the trauma site itself, the GCR were decreased (p less than 0.10), whereas the GCR were markedly increased in the remaining homolateral hemisphere (p less than 0.001). These results favour the use of steroids in the treatment of brain oedema following severe head injury despite the controversial results of various clinical trials.
Kostron
H
H
Daxenbichler
G
G
Mohsenipour
I
I
D000315:Adrenalectomy; D000818:Animals; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D001929:Brain Edema / Q000378:metabolism*; D001930:Brain Injuries / Q000378:metabolism*; D003907:Dexamethasone / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D051381:Rats; D011965:Receptors, Glucocorticoid / Q000032:analysis / Q000378:metabolism*
D011965:Receptors, Glucocorticoid; D003907:Dexamethasone