mRNA D(2) dopaminergic receptor expression after hypoxia-ischemia in rat immature brain.
Previous studies have shown a reduction of dopaminergic D(2) receptors (D(2)R) in the striatum after hypoxia-ischemia in newborn rats. We show here an early and transient reduction of mRNA D(2)R in nonatrophic brains following hypoxia-ischemia. The left carotid artery of P7 rats was ligated followed by hypoxia for 2 h. The rats were sacrificed after 24 h, 48 h and 14 days. D(2)R mRNA was studied by in situ hybridization, the cell number by conventional histology, and neuronal and astrocyte differentiation by immunohistochemistry. A 20% reduction of striatal mRNA D(2)R occurred 24 h after hypoxia-ischemia, whereas no reduction was observed after 48 h and 14 days. There were no differences in total cell number and in the expression of neuronal (MAP-1, MAP-2) and astrocyte (GFAP) markers between both brain hemispheres nor between control and hypoxia-ischemia animals. The early decrease in mRNA D(2)R could explain the delayed reduced D(2)R after neonatal hypoxia-ischemia.
Cantagrel
S
S
INSERM U316, Faculté de Pharmacie, Tours, France. sylvain.cantagrel@wanadoo.fr
Gressens
P
P
Bodard
S
S
Suc
A L
AL
Laugier
J
J
Guilloteau
D
D
Chalon
S
S
D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000737:chemistry / Q000473:pathology; D002452:Cell Count; D003342:Corpus Striatum / Q000737:chemistry / Q000473:pathology; D015870:Gene Expression; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D020925:Hypoxia-Ischemia, Brain / Q000378:metabolism*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D017448:Receptors, Dopamine D2 / Q000235:genetics*
D005904:Glial Fibrillary Acidic Protein; D012333:RNA, Messenger; D017448:Receptors, Dopamine D2