Lateralized effect of cerebral infarction on spinal fluid monoamine metabolite concentrations in rats

Using a rat model of stroke, we studied the effect of unilateral middle cerebral artery ligation on cerebrospinal fluid monoamine metabolites at different intervals over a 40-day postoperative period. Male Sprague-Dawley rats were divided into four groups: an unoperated control group (n = 9), a sham-operated group (n = 9), a right middle cerebral artery ligation group (n = 10), and a left middle cerebral artery ligation group (n = 10). One hundred microliters of cerebrospinal fluid were collected percutaneously from the cerebellomedullary cistern just before and 5, 20, and 40 days after the surgical procedure. Monoamine metabolites--3-methoxy-4-hydroxyphenylglycol (MHPG), 5-hydroxy-indoleacetic acid (5-HIAA), and homovanillic acid (HVA)--were measured using high-performance liquid chromatography. MHPG concentration in the right lesion group was significantly depleted from control levels 5, 20, and 40 days after surgery. No such depletion was observed in the left lesion rats. Concentration of 5-HIAA was relatively lower at Days 5 and 20 in the right lesion group than in the left lesion group. HVA concentration did not differ among the groups at any time. Our study has demonstrated a differential effect of unilateral ischemia on cerebrospinal fluid neurochemistry in rats dependent on the cerebral hemisphere involved.