[Changes in the vasoconstrictor action of noradrenaline and in its receptor-binding kinetics induced by sex hormones].
The role of testosterone/17 B estradiol ratios (T/E), on the vasoconstrictor effect of norepinephrine (NE), were studied in strips of carotid arteries from dogs. T/E of 0.1 (T = 1 nM/E = 10 nM) shifted the concentration/effect (C-E) curve of NE to the right. T/E of 10 (T = 10 nM/E = 1 nM) deviated it to the left. T (1 nM and 10 nM) shifted the C-E curve of NE to the right; E = 1 nM did not modify it; E = 10 nM, shifted it to the left. In microsomal fraction of carotid arteries, adrenergic receptors were characterized with 3H-NE binding, and the role of T/E ratios also studied. Under the influence of T/E ratio of 10, the agonist affinity (Ka), was increased from 100 nM-1 to 128 nM-1, the receptors density (Bmax), increased from 78.3 nM to 148 nM. E (1 nM) reduced Ka to 88 nM-1, T did not change any of these parameters. In conclusion, T/E ratios of 10, as in male, may enhance the vasoconstrictor activity of NE, increasing Ka and Bmax of adrenergic receptors.
Ceballos
G M
GM
Departamento de Farmacología, Escuela Superior de Medicina. I.P.N.
Gómez Villalobos
M J
MJ
Recamier
L M
LM
Trujillo
J
J
Yañez
R
R
Pastelín
G
G
D000818:Animals; D002339:Carotid Arteries / Q000187:drug effects / Q000378:metabolism; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004958:Estradiol / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009638:Norepinephrine / Q000493:pharmacokinetics / Q000494:pharmacology*; D011941:Receptors, Adrenergic / Q000187:drug effects* / Q000378:metabolism; D013739:Testosterone / Q000494:pharmacology*; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000493:pharmacokinetics / Q000494:pharmacology*
D011941:Receptors, Adrenergic; D014662:Vasoconstrictor Agents; D013739:Testosterone; D004958:Estradiol; D009638:Norepinephrine
Cambios en la acción vasoconstrictora de la noradrenalina y en su cinética de unión a receptores, inducidos por hormonas sexuales.