Changes in serum levels of SHBG, endogenous ligands and levonorgestrel induced by ethinylestradiol in NORPLANTR users

G. Noé, M. Pavez, H. B. Croxatto

Resultado de la investigación: Contribución a una revistaArtículorevisión exhaustiva

6 Citas (Scopus)


This work was done in search for a model to examine target organ response to fluctuations in serum levels of sex hormone-binding globulin (SHBG) and its ligands. The time course and magnitude of fluctuations of SHBG, levonorgestrel (L-Ng), estradiol (E2), testosterone (T) and dihydrotestosterone (DHT) in serum were examined during and after treatment with 50 ug of ethinylestradiol (EE2) daily for 10 days in 10 volunteer women using NORPLANTR implants. Six of these volunteers were also treated with 20 ug of EE2 daily for 7 days and two additional volunteers using a copper-T IUD were treated with 50 ug of EE2 daily for 7 days. In all cases, SHBG and L-Ng levels increased in a close parallel manner several-fold above basal levels during treatment, reaching a maximum around two days after the last EE2 pill. In contrast, the levels of E2 and T increased in one subject, decreased in 5 and remained unchanged in 4, while changes of DHT were unrelated to those of the other ligands. Since the L-Ng "secretion rate" by NORPLANTR implants is constant, it follows that the effect of EE2 on its levels is due to a decreased metabolic clearance rate, most likely secondary to the increased binding of L-Ng to SHBG in serum. This interpretation is in agreement with the close parallelism in the fluctuations of L-Ng and SHBG.

Idioma originalInglés
Páginas (desde-hasta)187-201
Número de páginas15
EstadoPublicada - 1 ene 1992

Áreas temáticas de ASJC Scopus

  • Medicina reproductiva
  • Ginecología y obstetricia


Profundice en los temas de investigación de 'Changes in serum levels of SHBG, endogenous ligands and levonorgestrel induced by ethinylestradiol in NORPLANT<sup>R</sup> users'. En conjunto forman una huella única.

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