Early Ontogeny of Iodocompound-Processing Neural Systems in Rat Brain
| Autor: | Mary B. Dratman, Floy L. Crutchfield |
|---|---|
| Rok vydání: | 1983 |
| Předmět: |
medicine.medical_specialty
Offspring Ontogeny Brain damage Biology Iodine Radioisotopes Myelin Cytosol Internal medicine medicine Animals Myelin Sheath Neurons Cerebrum Thyroid Brain Skeletal muscle Rats Inbred Strains Rats medicine.anatomical_structure Endocrinology Animals Newborn Pediatrics Perinatology and Child Health Female medicine.symptom Iodine Synaptosomes Hormone |
| Zdroj: | Pediatric Research. 17:8-14 |
| ISSN: | 1530-0447 0031-3998 |
| DOI: | 10.1203/00006450-198301000-00002 |
| Popis: | Summary: The distribution and localization of iodocompounds reaching the brain during early development were measured in rat pups nurtured on [1251]-containing milk from dams receiving. daily [125I-iodide injections. The regimen produced no measurable changes in growth and development of the offspring during the nursing period. Pup brains accumulated labeled iodocompounds at a faster rate than they grew and accumulated protein. The ratio of [125I]-iodocompounds in cerebrum relative to skeletal muscle increased progressively from day 11 through day 19. Significant differences in distribution of radioactivity in different brain regions were evident on day 1; developmental progress was associated with significantly different rates of regional accumulation of the isotope. On day 1 only 10% of the radioactivity in the postnuclear supernatant phase of brain homogenates was particle-bound; at the time of weaning, radioactivity in-brain particles accounted for more than 50%. Growing nerve cell processes and myelin, known to be major targets of early thyroid hormone deficiency or excess, were also the major subcellular sites of [125I-iodocompound localization in the developing rat brain. Overall, the ontogeny reflected progressive elaboration of iodocompound-processing neural systems resembling those recently recognized in adult brain. Speculation: Early deficiencies or excesses of aromatic amino acids are known to cause irreversible brain damage, presumably as a result of altered substrate availability for specific neural systems (1). A similar process may account for permanent brain changes resulting from abnormal iodocompound availability during the perinatal period. |
| Databáze: | OpenAIRE |
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