Changes in regional polyamine profiles in rat brains after transient cerebral ischemia (single versus repetitive ischemia): evidence for release of polyamines from injured neurons.
Reversible cerebral ischemia (of 5 min, 15 min, or 3-times 5 min) was produced in 14 Mongolian gerbils by occluding both common carotid arteries. After 72 h of recirculation, brains were frozen and processed for measuring regional levels of the polyamines putrescine, spermidine and spermine using HPLC and fluorescent detector. Ischemia induced a marked increase in putrescine levels throughout the brain, most pronounced after 3-times 5 min ischemia (P less than or equal to 0.05 - P less than or equal to 0.001). Spermine levels were significantly reduced, in the hippocampal CA1-subfield after 5 min of ischemia and, in addition, in the striatum and thalamus after 3-times 5 min ischemia. It is suggested that polyamines are released from necrotic neurons and cleared into the blood. Spermine, released from neurons into the extracellular compartment, may bind to the N-methyl-D-aspartate (NMDA) receptor of cells located in close vicinity and may thus render neurons vulnerable to otherwise subtoxic levels of excitotoxins.
Paschen
W
W
Max-Planck-Institute for Neurological Research, Department of Experimental Neurology, Cologne, F.R.G.
Widmann
R
R
Weber
C
C
D000818:Animals; D001921:Brain / Q000378:metabolism*; D005260:Female; D005849:Gerbillinae; D002546:Ischemic Attack, Transient / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D009928:Organ Specificity; D011073:Polyamines / Q000378:metabolism*; D011700:Putrescine / Q000378:metabolism; D013095:Spermidine / Q000378:metabolism; D013096:Spermine / Q000378:metabolism; D013997:Time Factors
D011073:Polyamines; D013096:Spermine; D013095:Spermidine; D011700:Putrescine