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Titolo:
Leptin attenuates follicular apoptosis and accelerates the onset of puberty in immature rats
Autore:
Almog, B; Gold, R; Tajima, K; Dantes, A; Salim, K; Rubinstein, M; Barkan, D; Homburg, R; Lessing, JB; Nevo, N; Gertler, A; Amsterdam, A;
Indirizzi:
Weizmann Inst Sci, Dept Mol Cell Biol, IL-76100 Rehovot, Israel Weizmann Inst Sci Rehovot Israel IL-76100 Biol, IL-76100 Rehovot, Israel Tel Aviv Med Ctr & Sch Med, LIS Matern Hosp, Dept Obstet & Gynecol, Tel Aviv, Israel Tel Aviv Med Ctr & Sch Med Tel Aviv Israel & Gynecol, Tel Aviv, Israel Hebrew Univ Jerusalem, Fac Agr, IL-76100 Rehovot, Israel Hebrew Univ Jerusalem Rehovot Israel IL-76100 , IL-76100 Rehovot, Israel Fukui Med Univ, Dept Obstet & Gynecol, Fukui, Japan Fukui Med Univ FukuiJapan ed Univ, Dept Obstet & Gynecol, Fukui, Japan Weizmann Inst Sci, Dept Mol Genet, IL-76100 Rehovot, Israel Weizmann Inst Sci Rehovot Israel IL-76100 enet, IL-76100 Rehovot, Israel Chaim Sheba Med Ctr, Dept Obstet & Gynecol, IL-52621 Tel Hashomer, Israel Chaim Sheba Med Ctr Tel Hashomer Israel IL-52621 21 Tel Hashomer, Israel
Titolo Testata:
MOLECULAR AND CELLULAR ENDOCRINOLOGY
fascicolo: 1-2, volume: 183, anno: 2001,
pagine: 179 - 191
SICI:
0303-7207(20011025)183:1-2<179:LAFAAA>2.0.ZU;2-X
Fonte:
ISI
Lingua:
ENG
Soggetto:
OVARIAN GRANULOSA-CELLS; ACUTE REGULATORY PROTEIN; OBESE GENE-PRODUCT; NORMAL FEMALE MICE; BODY-MASS INDEX; SERUM LEPTIN; CIRCULATING LEPTIN; OB PROTEIN; EXPRESSION; CHILDREN;
Keywords:
leptin; puberty; apoptosis; ovulation;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
60
Recensione:
Indirizzi per estratti:
Indirizzo: Amsterdam, A Weizmann Inst Sci, Dept Mol Cell Biol, IL-76100 Rehovot, Israel Weizmann Inst Sci Rehovot Israel IL-76100 0 Rehovot, Israel
Citazione:
B. Almog et al., "Leptin attenuates follicular apoptosis and accelerates the onset of puberty in immature rats", MOL C ENDOC, 183(1-2), 2001, pp. 179-191

Abstract

Human and rat granulosa cells express receptors to leptin which synergies with glucocorticoid hormones in stimulation of ovarian steroidogenesis. To examine whether leptin affects follicular development and maturation, we injected recombinant ovine leptin (300 ng- 10 mug/animal) daily to immature 21 day-old female rats. Non-treated rats reached puberty at 44.5 +/-1.6 (n=9) days. In contrast, in leptin treated animals, puberty was reached at 34.5+/-1.6 (n=9) days. Ovarian sections revealed hypertrophy of granulosa cells in leptin treated animals. Moreover, the number of ovulations was 2-fold higher in the treated animals compared to controls (3-4 ovulations versus 7-8 on the first three estrous cycles, P<0.001). Leptin dramatically reducedincidence of follicular apoptosis measured by TUNEL, and was already evident after 7 days of leptin injection (12% of apoptosis in leptin treated group compared to 52%, in controls, P<0.001). Maximal protection against apoptosis was achieved at 1-3 mug leptin/animal. The levels of FSH, LH, progesterone and the steroidogenic factors ADX and STAR were elevated earlier in development in the leptin treated animals compared to control animals which is in line with the achievement of early puberty in the leptin treated animals compared to non treated ones. To reveal whether modulation of death and survival genes is involved in leptin attenuation of follicular apoptosis, we examined the expression of the survival gene Bcl-2 and the death gene Baxin Western blots of ovarian homogenates. There was a pronounced elevation in Bcl-2 expression during 7-14 days of leptin injections up to 16.3-fold (P<0.001) compared to Bcl-2 expression in controls. Bax expression was elevated only 3.4 fold (P<0.001), leading to an increase in the Bcl-2/Bax ratio of 4.7 fold (P<0.001). Expression of the tumor suppressor gene p53 and the oncogene Mdm2 did not change significantly. Our data suggests that leptin may be involved in accelerating follicular maturation by attenuating follicular atresia and increasing the ratio of Bcl-2/Bax. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 19/01/20 alle ore 09:30:39