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Titolo:
Effects of aging on luteinizing hormone secretion, ovulation, and ovarian tissue-type plasminogen activator expression
Autore:
LaPolt, PS; Lu, JKH;
Indirizzi:
Calif State Univ Los Angeles, Dept Biochem & Microbiol, Los Angeles, CA 90032 USA Calif State Univ Los Angeles Los Angeles CA USA 90032 geles, CA 90032 USA Univ Calif Los Angeles, Sch Med, Dept Obstet & Gynecol, Los Angeles, CA 90095 USA Univ Calif Los Angeles Los Angeles CA USA 90095 Los Angeles, CA 90095 USA Univ Calif Los Angeles, Sch Med, Dept Neurobiol, Los Angeles, CA 90095 USAUniv Calif Los Angeles Los Angeles CA USA 90095 Los Angeles, CA 90095 USA Univ Calif Los Angeles, Sch Med, Neuroendocrinol Lab, Inst Brain Res, Los Angeles, CA 90095 USA Univ Calif Los Angeles Los Angeles CA USA 90095 Los Angeles, CA 90095 USA
Titolo Testata:
EXPERIMENTAL BIOLOGY AND MEDICINE
fascicolo: 2, volume: 226, anno: 2001,
pagine: 127 - 132
SICI:
1535-3702(200102)226:2<127:EOAOLH>2.0.ZU;2-F
Fonte:
ISI
Lingua:
ENG
Soggetto:
MIDDLE-AGED RATS; FEMALE RATS; ESTROUS CYCLES; FOLLICULAR PLASMINOGEN; HYPOPHYSECTOMIZED RATS; GONADOTROPIN-SECRETION; PROLACTIN SURGES; GRANULOSA-CELLS; LOCALIZATION; RESPONSIVENESS;
Keywords:
aging; ovulation; luteinizing hormone; plasminogen activator; rat; ovary;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
36
Recensione:
Indirizzi per estratti:
Indirizzo: LaPolt, PS Calif State Univ Los Angeles, Dept Biochem & Microbiol, Los Angeles, CA 90032 USA Calif State Univ Los Angeles Los Angeles CA USA 90032 0032 USA
Citazione:
P.S. LaPolt e J.K.H. Lu, "Effects of aging on luteinizing hormone secretion, ovulation, and ovarian tissue-type plasminogen activator expression", EXP BIOL ME, 226(2), 2001, pp. 127-132

Abstract

This study examined the effects of aging on LH surge magnitude, ovulation,and ovarian expression of tissue-type plasminogen activator (tPA), a protease implicated in follicular rupture. While mean LH levels and ovulation rates were similar in middle-aged cyclic and young groups, there was a significant correlation between peak LH levels and ovulation rates in individual rats, such that females with lower LH surges ovulated fewer ova, In a separate experiment, proestrous LH levels were characterized in young and middle-aged rats, followed by in situ hybridization analysis of ovarian tPA mRNA. In young proestrous rats, tPA expression was observed in thecal-interstitial cells and oocytes, but not granulosa cells, prior to the LH surge. Afterthe LH surge, there was a marked increase in tPA mRNA levels in granulosa cells of preovulatory, but not smaller follicles, peaking at 0200 hr estrus. By 0500 hr estrus, ovarian tPA expression declined, and ovulation had occurred, In contrast, LH-induced follicular tPA mRNA levels were dramaticallylower in middle-aged rats with attenuated LH surges, and persisting preovulatory follicles were common in ovaries of these females on estrus morning. These findings suggest that age-related declines in ovulatory function result in part from altered induction of ovarian tPA expression, likely due todecreased proestrous LH secretion.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 03/04/20 alle ore 20:27:57