Affiliations: Department of Neurosurgery, Yongdong Severance
Hospital, Yonsei University College of Medicine, Seoul, Korea | The Psychiatric Institute, Department of Psychiatry,
University of Illinois at Chicago, Chicago, Illinois, USA
Abstract: The endocrine system has been recognized as an important factor that
may contribute to the outcome of stroke. We tested in rats the hypothesis that
the pineal gland and/or its hormone melatonin may affect the outcome of a
transient cerebral arteries occlusion (CerAO). Reversible 90 min focal ischemia
was produced using a three-vessel occlusion method. Surgically or sham
pinealectomized rats were exposed to CerAO 15 days after surgery. Melatonin (4
x 2.5 mg/kg: 30 min prior to onset of CerAO, immediately after recirculation
was established, and 1 and 2 hr later) or its vehicle were administered
intraperitoneally. The outcome of CerAO was assessed by quantitative assay of
DNA damage or by Nissl staining and measurement of the infarct volume.
Pinealectomy increased both the extent of DNA damage and the infarct volume;
administration of melatonin to pinealectomized rats reduced both these markers
of brain injury. We propose that the pineal endocrine system may influence the
outcome of stroke. The mechanism of action and the pathophysiological role of
this system, e.g., in aging, should be further characterized.
Keywords: pineal gland, pinealectomy, melatonin, DNA damage, stroke, rat
