Biomaterial Database

Zinc protoporphyrin, zinc ion, and protoporphyrin reduce focal cerebral ischemia. 1996

Y J Zhao, and G Y Yang, and E F Domino

Department of Pharmacology, University of Michigan, Ann Arbor 48109-0632, USA.

OBJECTIVE Zinc protoporphyrin pretreatment protects against temporary focal ischemic brain injury in rats. However, it is not known whether the zinc or the protoporphyrin portion of zinc protoporphyrin has effects on focal cerebral ischemia. Hence, all three agents were compared with regard to infarct size and edema in a rat model of middle cerebral artery occlusion. METHODS Four groups of adult male Sprague-Dawley rats were subjected to 2 hours of temporary middle cerebral artery occlusion followed by 22 hours of reperfusion. Each group was pretreated 30 minutes before middle cerebral artery occlusion with 0.9% NaCl, and then three groups were given equimolar doses of zinc protoporphyrin, zinc chloride, or protoporphyrin, respectively. Regional cerebral blood flow in the ischemic cortex was monitored with a laser Doppler flowmeter. Cerebral infarct size, brain water content, and ion content were measured 24 hours after the onset of occlusion. RESULTS Regional cerebral blood flow during middle cerebral artery occlusion was approximately 9.2% to 13% of baseline in all four groups. Brain water content in the infarcted zone after temporary focal ischemia in control, zinc protoporphyrin, zinc chloride, and protoporphyrin groups was 85.7%, 80.6%, 85.6%, and 81.4%, respectively. Brain sodium content in the same areas in all four groups paralleled the water content. Infarct size in the controls and groups treated with zinc protoporphyrin, zinc, and protoporphyrin was 25.6%, 7.2%, 7.6%, and 7.2%, respectively. Compared with the control group, the infarct volume in all three treated groups was significantly reduced (P < .05). CONCLUSIONS The present results indicate that zinc protoporphyrin, but also zinc and protoporphyrin, contribute to brain-protective effects when administered early in a temporary focal ischemia model. Zinc chloride reduced infarct size but not edema formation when compared with zinc protoporphyrin and protoporphyrin. Zinc ion in vivo has brain-protective effects, confirming in vitro studies previously reported by some but contrary to reports of others. Blood versus brain neuropil and cell body concentrations of zinc ion need to be studied in the future to define the precise role of zinc in the complex mechanisms involved in brain ischemia.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D011524	Protoporphyrins	Porphyrins with four methyl, two vinyl, and two propionic acid side chains attached to the pyrrole rings. Protoporphyrin IX occurs in hemoglobin, myoglobin, and most of the cytochromes.
D001923	Brain Chemistry	Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.	Chemistry, Brain,Brain Chemistries,Chemistries, Brain
D001929	Brain Edema	Increased intracellular or extracellular fluid in brain tissue. Cytotoxic brain edema (swelling due to increased intracellular fluid) is indicative of a disturbance in cell metabolism, and is commonly associated with hypoxic or ischemic injuries (see HYPOXIA, BRAIN). An increase in extracellular fluid may be caused by increased brain capillary permeability (vasogenic edema), an osmotic gradient, local blockages in interstitial fluid pathways, or by obstruction of CSF flow (e.g., obstructive HYDROCEPHALUS). (From Childs Nerv Syst 1992 Sep; 8(6):301-6)	Brain Swelling,Cerebral Edema,Cytotoxic Brain Edema,Intracranial Edema,Vasogenic Cerebral Edema,Cerebral Edema, Cytotoxic,Cerebral Edema, Vasogenic,Cytotoxic Cerebral Edema,Vasogenic Brain Edema,Brain Edema, Cytotoxic,Brain Edema, Vasogenic,Brain Swellings,Cerebral Edemas, Vasogenic,Edema, Brain,Edema, Cerebral,Edema, Cytotoxic Brain,Edema, Cytotoxic Cerebral,Edema, Intracranial,Edema, Vasogenic Brain,Edema, Vasogenic Cerebral,Swelling, Brain
D002544	Cerebral Infarction	The formation of an area of NECROSIS in the CEREBRUM caused by an insufficiency of arterial or venous blood flow. Infarcts of the cerebrum are generally classified by hemisphere (i.e., left vs. right), lobe (e.g., frontal lobe infarction), arterial distribution (e.g., INFARCTION, ANTERIOR CEREBRAL ARTERY), and etiology (e.g., embolic infarction).	Anterior Choroidal Artery Infarction,Cerebral Infarct,Infarction, Cerebral,Posterior Choroidal Artery Infarction,Subcortical Infarction,Cerebral Infarction, Left Hemisphere,Cerebral Infarction, Right Hemisphere,Cerebral, Left Hemisphere, Infarction,Cerebral, Right Hemisphere, Infarction,Infarction, Cerebral, Left Hemisphere,Infarction, Cerebral, Right Hemisphere,Infarction, Left Hemisphere, Cerebral,Infarction, Right Hemisphere, Cerebral,Left Hemisphere, Cerebral Infarction,Left Hemisphere, Infarction, Cerebral,Right Hemisphere, Cerebral Infarction,Right Hemisphere, Infarction, Cerebral,Cerebral Infarctions,Cerebral Infarcts,Infarct, Cerebral,Infarction, Subcortical,Infarctions, Cerebral,Infarctions, Subcortical,Infarcts, Cerebral,Subcortical Infarctions
D002545	Brain Ischemia	Localized reduction of blood flow to brain tissue due to arterial obstruction or systemic hypoperfusion. This frequently occurs in conjunction with brain hypoxia (HYPOXIA, BRAIN). Prolonged ischemia is associated with BRAIN INFARCTION.	Cerebral Ischemia,Ischemic Encephalopathy,Encephalopathy, Ischemic,Ischemia, Cerebral,Brain Ischemias,Cerebral Ischemias,Ischemia, Brain,Ischemias, Cerebral,Ischemic Encephalopathies
D002560	Cerebrovascular Circulation	The circulation of blood through the BLOOD VESSELS of the BRAIN.	Brain Blood Flow,Regional Cerebral Blood Flow,Cerebral Blood Flow,Cerebral Circulation,Cerebral Perfusion Pressure,Circulation, Cerebrovascular,Blood Flow, Brain,Blood Flow, Cerebral,Brain Blood Flows,Cerebral Blood Flows,Cerebral Circulations,Cerebral Perfusion Pressures,Circulation, Cerebral,Flow, Brain Blood,Flow, Cerebral Blood,Perfusion Pressure, Cerebral,Pressure, Cerebral Perfusion
D004353	Drug Evaluation, Preclinical	Preclinical testing of drugs in experimental animals or in vitro for their biological and toxic effects and potential clinical applications.	Drug Screening,Evaluation Studies, Drug, Pre-Clinical,Drug Evaluation Studies, Preclinical,Drug Evaluations, Preclinical,Evaluation Studies, Drug, Preclinical,Evaluation, Preclinical Drug,Evaluations, Preclinical Drug,Medicinal Plants Testing, Preclinical,Preclinical Drug Evaluation,Preclinical Drug Evaluations,Drug Screenings,Screening, Drug,Screenings, Drug
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014463	Ultrasonography	The visualization of deep structures of the body by recording the reflections or echoes of ultrasonic pulses directed into the tissues. Use of ultrasound for imaging or diagnostic purposes employs frequencies ranging from 1.6 to 10 megahertz.	Echography,Echotomography,Echotomography, Computer,Sonography, Medical,Tomography, Ultrasonic,Ultrasonic Diagnosis,Ultrasonic Imaging,Ultrasonographic Imaging,Computer Echotomography,Diagnosis, Ultrasonic,Diagnostic Ultrasound,Ultrasonic Tomography,Ultrasound Imaging,Diagnoses, Ultrasonic,Diagnostic Ultrasounds,Imaging, Ultrasonic,Imaging, Ultrasonographic,Imaging, Ultrasound,Imagings, Ultrasonographic,Imagings, Ultrasound,Medical Sonography,Ultrasonic Diagnoses,Ultrasonographic Imagings,Ultrasound, Diagnostic,Ultrasounds, Diagnostic