High-affinity binding of T3 to epididymis nuclei.
Arch Androl
; 44(3): 187-91, 2000.
Article
em En
| MEDLINE
| ID: mdl-10864365
Thyroid hormones play an important role in epididymal function. Hypothyroid animals experience a significant decrease in the number and forward motility of sperm and a remarkable impairment of epididymal morphology. However, it is yet unknown if such activity is due to direct actions of iodothyronines on the target epididymis. The eventual identification of T3 receptors in the nucleous of epididymal cells becomes relevant. For this reason, the authors searched for specific high-affinity binding of T3 to these nuclei. Twenty prepuberal male Wistar rats were used. The testes and epididymis were approached as one unit through a scrotal incision. The fat-free epididymides were subjected to standard techniques to prepare the nuclei for incubations with 125I-T3 concentrations, ranging from 0.5 x 10(-9) to 2.0 x 10(-11) M. Calculations of association constants and binding capacities were performed according to Scatchard. A single binding site with a Ka of 3.06 +/- 0.6 x 10(9) M(-1) or Kd of 3.26 +/- 0.6 x 10(10) M and a maximal binding capacity of 0.11 +/- 0.02 pmol T3/microg DNA were observed. It is concluded that these nuclei contain a specific T3 receptor. This finding strongly suggests that thyroid hormones have direct effects on the epididymis.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tri-Iodotironina
/
Núcleo Celular
/
Epididimo
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Arch Androl
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Reino Unido