Glutamate enhances brain damage and albumin content in cerebrospinal fluid after intracarotid protamine infusion.
The blood-brain barrier was opened by intracarotid infusion of 5 mg protamine sulfate in 100 microliters 0.9% NaCl over a period of 30 s either alone or followed by infusion of 10 mg L-glutamate in 0.9% NaCl. Glutamate alone was infused in four control rats. Cisternal cerebrospinal fluid (CSF) was withdrawn before protamine administration and before the brains were fixed in situ 1, 24 or 72 h later. The albumin extravasation and glial reactivity was evaluated by immunohistochemistry on paraffin sections. The CSF albumin was significantly increased in both the protamine and protamine/glutamate groups but remained high at 24 and 72 h in the protamine/glutamate group only. Spongiotic lesions with shrunken nerve cells were observed 1 and 24 h after infusion of protamine alone or in combination with glutamate. Whereas such changes were not seen 72 h after protamine infusion, they remained and had progressed at 72 h in the protamine/glutamate group, indicating that glutamate induces delayed cellular damage when given access to the brain through an altered blood-brain barrier.
Westergren
I
I
Department of Neurology, Lund University Hospital, Sweden.
Nordborg
C
C
Johansson
B B
BB
D000818:Animals; D001921:Brain / Q000473:pathology; D001925:Brain Damage, Chronic / Q000134:cerebrospinal fluid / Q000401:mortality / Q000473:pathology*; D002339:Carotid Arteries; D005971:Glutamates / Q000008:administration & dosage / Q000494:pharmacology*; D018698:Glutamic Acid; D007150:Immunohistochemistry; D007269:Injections, Intra-Arterial; D008297:Male; D011479:Protamines / Q000008:administration & dosage* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012709:Serum Albumin / Q000134:cerebrospinal fluid*; D016019:Survival Analysis; D013997:Time Factors
D005971:Glutamates; D011479:Protamines; D012709:Serum Albumin; D018698:Glutamic Acid