Changes in hypothalamic calmodulin concentration induced by perinatal hormone manipulation in the rat.
Calmodulin (CaM) presence and concentration was determined (RIA) in the rat hypothalamus (2, 6, 12, 24 h and 90 days after birth) in vehicle-treated animal (controls), in testosterone propionate (TP)-treated females (30 microg/rat subcutaneously 1 h after birth) and in tamoxifen-treated males (200 microg/rat subcutaneously 1 h after birth). CaM concentration, either as total content/hypothalamus or as concentration per mg ww, was significantly higher in both male and female adult rats than in newborn subjects. CaM concentration/mg protein increased with age, being two times higher in adult males and greater than three times higher in adult females than in their respective newborns. Two, 12, and 24 h after birth CaM concentration was significantly lower in control females than in control males. This relation was reversed in adults in which CaM concentration was higher in females. The application of TP to the females and tamoxifen to the males, induced a significant decrease in CaM/mg protein, both in the newborn (2 and 6 h) and in the adult animals. In adults, treated females had CaM concentrations similar to those found in control males. Our data suggest: first, a lasting effect of newborn hormonal treatment upon the CaM concentration in rat hypothalamus; second, that CaM is preferentially synthesized in the adult female hypothalamus, indicating an important role of this protein in female reproductive function.
Rodríguez-Medina
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División de Investigación Biomédica, Unidad de Investigación Médica en Biología de la Reproducción, Hospital de Gineco-Obstetrica Luis Castelazo Ayala, IMSS México DF, México.
Vergara
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Chavarria
M E
ME
Rosado
A
A
Reyes
A
A
D000818:Animals; D000831:Animals, Newborn; D002147:Calmodulin / Q000378:metabolism*; D005260:Female; D007031:Hypothalamus / Q000254:growth & development / Q000378:metabolism*; D008297:Male; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D012733:Sex Differentiation; D013629:Tamoxifen / Q000494:pharmacology; D013739:Testosterone / Q000494:pharmacology
D002147:Calmodulin; D013629:Tamoxifen; D013739:Testosterone