Pituitary-ovarian axis during lactational amenorrhoea. II. Longitudinal assessment of serum FSH polymorphism before and after recovery of menstrual cycles
Autor: | S.B. Cigorraga, E.H. Pellizzari, Ethel V. Velasquez, Stella Campo, S. Creus, R.V. Trigo, Horacio B. Croxatto |
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Rok vydání: | 2005 |
Předmět: |
endocrine system
medicine.medical_specialty medicine.drug_class media_common.quotation_subject Ovary Biology Anovulation Follicle-stimulating hormone Ovarian Follicle Internal medicine Follicular phase medicine Humans Lactation Protein Isoforms Longitudinal Studies Amenorrhea Menstrual cycle Menstrual Cycle media_common Chromatography Rehabilitation Postpartum Period Obstetrics and Gynecology medicine.disease Endocrinology medicine.anatomical_structure Reproductive Medicine Pituitary Gland Female medicine.symptom Gonadotropin Follicle Stimulating Hormone Breast feeding hormones hormone substitutes and hormone antagonists |
Zdroj: | Human reproduction (Oxford, England). 21(4) |
ISSN: | 0268-1161 |
Popis: | BACKGROUND: The association of normal serum levels of immunoassayable gonadotrophins with anovulation during lactational amenorrhoea (LA) has not been fully explained. METHODS: Serum FSH polymorphism was analysed in 10 women during LA between days 60 and 70 post-partum and again, in the mid-follicular phase (MFP), after resuming menstrual cyclicity. FSH microheterogeneity was characterized according to charge, using preparative isoelectric focusing, and according to the inner structure of carbohydrate chains, using lectin chromatography. RESULTS: A significantly higher proportion of FSH charge isoforms isolated below pH 4.10 and a lower proportion of FSH isoforms bearing highly branched oligosaccharides were observed during LA when compared to MFP. Further analysis with higher resolution showed that FSH charge isoforms, isolated in the lower pH range in LA, corresponded to FSH molecules bearing highly branched and biantennary oligosaccharides. FSH isoforms bearing hybrid-type oligosaccharides were only present during LA. The circulating FSH isoform mix was significantly less bioactive in LA than in MFP. LA is characterized by a more acidic mix of FSH isoforms, containing hormone bearing less processed oligosaccharides, with decreased biopotency in comparison with the follicular phase. CONCLUSIONS: This FSH microheterogeneity may be one of the critical factors contributing to incomplete follicular development and anovulation during LA. |
Databáze: | OpenAIRE |
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