[Histological, biochemical and immunocytochemical data on the postnatal development of the hypothalamic magnocellular nucleus in the congenital hypothyroid rat].
1 The effects of congenital hypothyroidism on the postnatally developing hypothalamus and, particularly on the developing magnocellular nuclei and their vasopressinergic neurons, were studied by means of complementary approaches, such as histology, biochemistry and immunocytochemistry. 2 In normal rat, all the results show a precocious development of hypothalamus, and particularly of its magnocellular nuclei. 3 In hypothyroid rat, in showing that the nucleic acid and protein content of hypothalamus is diminished by the same magnitude than its wet weight, the results display a normal average cellularity and cell size. In the magnocellular nuclei of 10, 20 and 30 day-old rats, the neuronal density and cell size appear to be unaffected, except for the NSO at 35 days of age in which the two parameters are increased and decreased, respectively. With respect to vasopressinergic neurons in 35 day-old rats, their density and percentage in total cell population, as well as the axonal density are somewhat increased, the greater differences always significant being shown only in the NPV. Whatever the nuclei considered, the density of axonal varicosities does not differ from normal value. Finally, the vasopressin concentration of hypothalamus is significantly increased. Thus, it may be concluded that the mainly prenatal development of these vasopressinergic hypothalamic nuclei seems to be relatively spared from neo- and postnatal thyroid deficiency.
Laboratoire de Physiologie comparée, UA 1197 du CNRS, Montpellier.
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D000818:Animals; D002452:Cell Count; D003409:Congenital Hypothyroidism; D004247:DNA / Q000378:metabolism; D007031:Hypothalamus / Q000254:growth & development* / Q000473:pathology; D007037:Hypothyroidism / Q000473:pathology / Q000503:physiopathology; D007150:Immunohistochemistry; D009474:Neurons / Q000473:pathology; D009481:Neurophysins / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D051381:Rats; D014667:Vasopressins / Q000502:physiology
D009481:Neurophysins; D011506:Proteins; D014667:Vasopressins; D004247:DNA
Données histologiques, biochimiques et immunocytochimiques sur le développement postnatal des noyaux magnocellulaires hypothalamiques du rat hypothyroïdien congénital.