Effects of Aging on Luteinizing Hormone Secretion, Ovulation, and Ovarian Tissue-Type Plasminogen Activator Expression

LaPolt, Philip S.; Lu, John

doi:10.1177/153537020122600210

Cited by 12 publications

(10 citation statements)

References 36 publications

(26 reference statements)

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“…PE females display follicular growth, but preovulatory follicles fail to ovulate due to impaired neuroendocrine control of luteinizing hormone secretion (Anzalone et al 1998, Chern et al 2000, LaPolt & Lu 2001. Thus, as observed in this study, ovaries of PE rats may contain healthy Graafian (or preovulatory-like) follicles (Fig.…”

supporting

confidence: 52%

Relationship between FoxO1 protein levels and follicular development, atresia, and luteinization in the rat ovary

Wei

LaPolt

2003

Journal of Endocrinology

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FoxO1 is a transcription factor implicated in a growing number of physiological processes, including apoptosis, cell cycle progression, and insulin signaling. Recent findings indicate that FSH and growth factors influence ovarian functions in part through regulation of FoxO1. The present study utilized immunohistochemical analysis to determine the ovarian localization and regulation of FoxO1 protein levels in neonatal rats, immature rats during gonadotropin-induced follicular development, ovulation, and luteinization, and in spontaneously developing ovarian cysts of aging rats. In postnatal rats, FoxO1 immunoreactivity was very faint in ovaries of 5-and 10-day-old females. In contrast, strong immunoreactivity was observed in granulosa cells of larger developing follicles at 25 days of age. To stimulate follicle development, immature female rats received equine chorionic gonadotropin (eCG) followed 52 h later by an ovulatory dose of human chorionic gonadotropin (hCG). Prior to gonadotropin treatment, moderate FoxO1 immunoreactivity was observed in granulosa cells of small follicles.Subsequently, treatment with eCG markedly decreased FoxO1 protein levels in granulosa cells of healthy antral and preovulatory follicles. Interestingly, FoxO1 staining was observed in cumulus and antral, but not mural granulosa cells of preovulatory follicles. Induction of ovulation and luteinization with hCG further decreased ovarian FoxO1 levels, with no staining evident in corpora lutea. At all time points, the most intensive FoxO1 staining was observed in granulosa cells of atretic follicles, with predominantly nuclear localization. Similarly, while FoxO1 levels were low in granulosa cells of preovulatory follicles in proestrous rats, FoxO1 staining was intense in granulosa cells of spontaneously developing cystic follicles in aged, acyclic females. Together, these findings indicate that FoxO1 is expressed in a regulated, cell-specific manner during ovarian follicular development, atresia and luteinization, suggesting roles in these physiological processes.

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confidence: 52%

Relationship between FoxO1 protein levels and follicular development, atresia, and luteinization in the rat ovary

Wei

LaPolt

2003

Journal of Endocrinology

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“…Plasmin is an activated form of plasminogen and the combination of plasminogen and plasminogen activators (PAs) serve as unlimited supply of proteolytic capacity. It is known from animal experiments that mouse granulosa cells that line the interior of the follicle, as well as theca cells produce different PAs that activate plasmin [19, 20]. In addition to plasmin’s ability to degrade fibrin, it also generates active collagenase [21, 22].…”

Section: Discussionmentioning

confidence: 99%

Interpenetrating fibrin–alginate matrices for in vitro ovarian follicle development

et al. 2009

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In this report, we investigate the fibrin-alginate inter penetrating network (FA-IPN) to provide dynamic cell-responsive mechanical properties, which we apply to the in vitro growth of ovarian follicles. The mechanical properties and polymerization rate of the gels were investigated by rheology, and the fiber structure was imaged by electron microscopy. Using a mouse model, twolayered secondary follicles were encapsulated in FA-IPNs, and growth, morphology, hormone production, fibrin degradation rate and the numbers of competent eggs were assessed. The initial mechanics of the FA-IPN are determined by the composite material, and subsequent degradation of fibrin by the encapsulated cells would produce a material with mechanical properties due to the alginate alone. The rate of meotically competent oocytes produced by culture in FA-IPN was 82%, which was significantly greater than in alginate alone. This increase in oocyte quality is an important step in identifying 3D culture systems that can provide a fundamental tool to investigate follicle maturation, and may be applied to promote the growth of human follicles, which can be used to provide reproductive options for women facing a cancer diagnosis

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“…Four rat models, the postnatal, immature, adult and acyclic aged persistent estrous (PE) rat models, are widely used in the literature [9][10][11][12][13][14][15][16][17][18][19][20][21]. Since follicular development in the rat occurs postnatally [11][12][13], we examined the postnatal rat model to determine the relationships between ovarian cAMP l e v e l , c A M P -P D E a c t i v i t y a n d f o l l i c u l a r development.…”

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confidence: 99%

“…Adult rats usually display typical estrous cycle patterns [17,18]. Acyclic aged PE rats display follicular growth, but preovulatory f o l l i c l e s f a i l t o o v u l a t e d u e t o i m p a i r e d neuroendocrine control of luteinizing hormone secretion [19][20][21]. In order to examine the roles of c A M P -P D E i n t h e o v a r y o f r a t s d u r i n g development and aging, we investigated the ovarian cAMP levels and cAMP-specific PDE activities in the ovaries of four different rat models.…”

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confidence: 99%

Changes of Cyclic AMP Levels and Phosphodiesterase Activities in the Rat Ovary

Wang

Wei

Jiang

et al. 2007

Journal of Reproduction and Development

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Abstract. Cyclic AMP (cAMP) is a second messenger that plays a critical role in follicular recruitment, development and luteinization in the mammalian ovary. The cellular level of cAMP is largely dependent on the activity of phosphodiesterase (PDE), which degrades cAMP into 5'-AMP. The present study was conducted to investigate the level of cAMP and the activity of cAMP-PDE in postnatal rats; immature rats during gonadotropin-primed follicular development, ovulation and luteinization; adult rats during normal estrous cycling; and aged rats that spontaneously developed persistent estrous (PE) by radioimmunoassay (RIA). All four rat models were confirmed by histological examination of one ovary and assayed using the other ovary by RIA. In the postnatal rats, the ovarian cAMP level was high on day 10 after birth, while ovarian cAMP-PDE activity was highest at 21 days of age. In the immature female rats, both the ovarian cAMP level and cAMP-PDE activity increased remarkably after treatment with equine chorionic gonadotropin (eCG), increased continuously 24 h after injection of human chorionic gonadotropin (hCG) for induction of ovulation and luteinization, and then declined significantly. In the adult rats during the normal estrous cycle, the ovarian cAMP levels were low on the day of estrus, and there were no significant changes in ovarian cAMP-PDE activity throughout the estrous cycle. In the PE rats, the ovarian cAMP levels were similar to those of the adult rats on the day of estrus but were lower than those on the other days of the estrous cycle; ovarian cAMP-PDE activity was lower than that in the adult rats on any day of the estrous cycle. Together, these findings indicate that the ovarian cAMP level and cAMP-PDE activity were regulated in a stage-dependent manner during ovarian follicular development, atresia and luteinization and providing evidences that cAMP and cAMP-specific PDEs are involved in these physiological processes.

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Effects of Aging on Luteinizing Hormone Secretion, Ovulation, and Ovarian Tissue-Type Plasminogen Activator Expression

Cited by 12 publications

References 36 publications

Relationship between FoxO1 protein levels and follicular development, atresia, and luteinization in the rat ovary

Relationship between FoxO1 protein levels and follicular development, atresia, and luteinization in the rat ovary

Interpenetrating fibrin–alginate matrices for in vitro ovarian follicle development

Changes of Cyclic AMP Levels and Phosphodiesterase Activities in the Rat Ovary

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