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Updated: Aug 12, 2026
A Piglet Model of Neonatal Hypoxic-Ischemic Encephalopathy
Published on: May 16, 2015
Lead encephalopathy in neonatal Long-Evans rats: morphologic studies
Insights
Neonatal lead exposure in rats caused severe brain damage, behavioral changes, and death. Lead intoxication primarily damages developing CNS capillaries, leading to lead encephalopathy.
Area of Science:
- Neuroscience
- Toxicology
- Developmental Biology
Background:
- Lead exposure is a significant public health concern, particularly for developing organisms.
- Lead encephalopathy is a severe neurological disorder resulting from lead poisoning.
Purpose of the Study:
- To investigate the pathological effects of lead acetate on the developing central nervous system (CNS) in neonatal rats.
- To identify the primary cellular targets of lead toxicity in the brain.
Main Methods:
- Neonatal Long-Evans rats were administered daily doses of lead acetate.
- Histopathological analysis of brain tissues (cerebellum, choroid plexus, cerebral cortex, corpus striatum) was performed.
- Electron microscopy and Golgi preparations were used to examine vascular anomalies.
Main Results:
- Lead-exposed rats exhibited behavioral changes, impaired weight gain, paraplegia, and mortality.
- Significant hemorrhages and edema were observed in the cerebellum.
- Lead intoxication was found to damage growing capillaries in the CNS, specifically endothelial buds (angioblasts).
Conclusions:
- Lead encephalopathy in neonatal rats is characterized by severe cerebellar damage and vascular anomalies.
- Developing CNS capillaries, particularly endothelial buds, are highly sensitive to lead toxicity.
- The death of these vascular structures is likely the primary cause of lead-induced encephalopathy.
Abstract:
Lead encephalopathy was produced in neonatal Long-Evans rats by administering daily doses of lead acetate (600 milligrams of lead acetate/kilogram of body weight) through an esophageal catheter. Experimental rat pups showed behavioral changes, failed to gain weight at the same rate as controls, developed a paraplegia and died by 15 days of age. Lead analysis showed very high blood and tissue lead levels. Sequential histopathologic changes were studied in the cerebellum with observations also made in the choroid plexus, cerebral cortex and corpus striatum. Emphasis was placed on the cerebellum because this region of the brain was most severely altered. Petechial hemorrhages were evident in the cerebellum at three days and two days later the hemorrhagic lesions were almost confluent. The molecular and Purkinje cell layers were most extensively damaged by the hemorrhage. At eight, nine and ten days hemorrhages were fewer and massive amounts of edema fluid accumulated in the internal granular layer. Vascular anomalies of developing lead poisoned rats were examined with electron microscopy and with Golgi preparations. The evidence indicates that growing capillaries are the primary structure of the central nervous system (CNS) damaged by lead intoxication. The endothelial bud (or angioblast) appears to be a structure sensitive to lead poisoning and the encephalopathy probably results from the death of many of these buds.
