Histometry of normal thyroid glands in neonatal and adult rats.
The present histometric study is on thyroid glands of Wistar rats ranging in age from 0 to 120 days. The mean volume of one lobe of the thyroid in 4-month-old animals was some 22-, 10-, 5-, and 3-fold greater, respectively, than the volumes in the newborn, 5-, 10-, and 30-day-old rats. At 4 months of age the mean length of the lobe was 3 times greater than at birth. The volumetric fractions (Vv) of the different histological components (follicular cells, C-cells, colloid, and interstitial tissue) changed considerably in the course of development. The Vv of follicular cells diminished from 61.4% at birth to 37.2% at 4 months. C-cells increased from 2.9% in the newborn to 4% at 15 days, with no further significant change at 4 months. Colloid and stroma together represented 35.7% at birth, increasing to 58.5% at 120 days. In the course of the first 4 months of life, the absolute volumes occupied by follicular cells, C-cells, colloid, and stroma increased 13.25, 30.75, 38.6, and 33.7 times, respectively; these changes reflect the variations that occur in the volume of the gland and the Vv throughout postnatal development.
Conde
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Departamento de Biología Celular, Facultad de Medicina, Universidad de Sevilla, Spain.
Martin-Lacave
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Gonzalez-Campora
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Galera-Davidson
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D000818:Animals; D000831:Animals, Newborn / Q000033:anatomy & histology; D002116:Calcitonin / Q000032:analysis*; D004848:Epithelium / Q000033:anatomy & histology; D005260:Female; D007124:Immunoenzyme Techniques; D008297:Male; D009024:Morphogenesis; D051381:Rats; D011919:Rats, Inbred Strains; D013961:Thyroid Gland / Q000033:anatomy & histology* / Q000737:chemistry
D002116:Calcitonin