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Titolo:
ACTIVIN CAUSES PREMATURE SUPEROVULATION
Autore:
ERICKSON GF; KOKKA S; RIVIER C;
Indirizzi:
UNIV CALIF SAN DIEGO,DEPT REPROD MED,9500 GILMAN DR LA JOLLA CA 92093 SALK INST BIOL STUDIES,CLAYTON FDN LABS PEPTIDE BIOL LA JOLLA CA 92037
Titolo Testata:
Endocrinology
fascicolo: 11, volume: 136, anno: 1995,
pagine: 4804 - 4813
SICI:
0013-7227(1995)136:11<4804:ACPS>2.0.ZU;2-2
Fonte:
ISI
Lingua:
ENG
Soggetto:
RAT GRANULOSA-CELLS; CHRONIC INTRACEREBROVENTRICULAR INFUSION; PITUITARY-GONADAL AXIS; RECOMBINANT ACTIVIN; CYCLING RATS; INTERLEUKIN-1-BETA ALTERS; FOLLICULAR RECRUITMENT; PROTEIN FOLLISTATIN; LUTEINIZING-HORMONE; MENSTRUAL-CYCLE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
46
Recensione:
Indirizzi per estratti:
Citazione:
G.F. Erickson et al., "ACTIVIN CAUSES PREMATURE SUPEROVULATION", Endocrinology, 136(11), 1995, pp. 4804-4813

Abstract

In the rat ovary, follicle cells produce and respond to activin, but as yet, the functional significance of the autocrine/paracrine effectsof ovarian activin remains equivocal. To assess the effects of activin on folliculogenesis, normal cycling female rats were injected once every 8 h over a 40-h period with recombinant human activin A (120 mu g/kg) beginning at 1300 h on estrus (day 1 of treatment). A total of 10rats were injected with activin in 2 separate experiments. On days 3 and 4 of treatment, blood was obtained for hormone measurements, and the ovaries were removed for histology. Follicle counts were performed in 1 ovary from 3 representative animals in each treatment group. All antral (Graafian) follicles 300 mu m or more in diameter were measuredand classified as healthy or atretic based on the number of pyknotic nuclei in the largest cross-section. On day 3, all rats were in diestrus (diestrous day 2). After 3 days of activin administration, serum levels of estradiol were increased 200%, progesterone levels were decreased 67%, and FSH levels were unchanged compared with those in matched controls. By day 4 (i.e. 1 day after the last injection), no changes in the levels of these hormones were observed. Injection of activin for3 days did not change the total number of antral follicles per ovary (control, 41.3 +/- 4.9; activin, 43.7 +/- 3.9); however, activin significantly increased the total number of atretic follicles (control, 69%; activin, 92%). Morphometric analysis of the ovaries removed on day 3showed a marked increase (2-fold) in the number of large follicles, but most (89%) were atretic. Follicle counts suggested that the additional large follicles may have come from the pool of healthy small follicles. Histological studies showed that some of the day 3 activin-treated follicles had initiated ovulation. On day 4, control and activin treated animals were at proestrus and estrus, respectively. Therefore, activin shortened the estrous cycle by 1 day. Little or no change in the follicle populations was observed in day 4 control ovaries. Interestingly, however, in 2 of the 3 activin treated animals, 1 set of large follicles had ovulated (12 +/- 1 expanded egg cumulus complexes/oviduct), and another set (13 +/- 2) was just about to rupture. The activin-exposed oocytes (tubal and follicular) appeared arrested in metaphase I. After ovulation, activin-treated follicles developed into typical corpora lutea. No ovulations were found in control animals. We concludethat multiple injections of activin A into adult cycling rats leads to premature superovulation of immature eggs from large follicles, manyof which appear atretic.

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Documento generato il 07/07/20 alle ore 11:48:57