Ob receptor in rabbit ovary and leptin in vitro regulation of corpora lutea

Zerani, Massimo; Boiti, Cristiano; Zampini, Danilo; Brecchia, Gabriele; Dall’Aglio, Cecilia; Ceccarelli, Piero; Gobbetti, Anna

doi:10.1677/joe.1.05507

Cited by 62 publications

(35 citation statements)

References 56 publications

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“…Our immunohistochemical results have consistently shown a stronger Ob-R-like reaction in the basal cytoplasmic region of secretory cells where the rough endoplasmic reticulum is more likely localized. These findings are in agreement with recent reports which showed Ob-R-like immunoreactivity in the rough endoplasmic reticulum, Golgi apparatus and cytoplasmic matrix of hypothalamic neurones (Diano et al 1998), glial cells (Funahashi et al 2000), COS-7 cells (Barr et al 1999) and different ovarian structures of rabbits (Zerani et al 2004).…”

Section: Discussionsupporting

confidence: 94%

“…The present work suggests that leptin is a modulator of oviductal PG synthesis, given that this hormone inhibited PGF2 release, whilst it stimulated that of PGE2. This role in PG synthesis regulation was also confirmed, although indirectly, by our recent findings showing an increase of PGF2 release induced by leptin in rabbit corpora lutea (Zerani et al 2004). Even if no direct data exist on the interaction between blood leptin concentration and subsequent successful implantation, the idea that leptin might affect fertility and fecundity, via oviductal PG synthesis, is intriguing.…”

Section: Discussionmentioning

confidence: 58%

“…Within the reproductive system, the action of leptin is exerted both centrally, in the hypothalamus and pituitary, and peripherally through binding with its specific receptor (Ob-R), which has been identified in various tissues of the gonadic axis of several species (Spicer & Francisco 1997, Finn et al 1998, Jin et al 2000, Kitawaki et al 2000, Koshiba et al 2001, Ryan et al 2002 and recently also in the corpora lutea of rabbits (Zerani et al 2004). These observations, together with the finding of the effects induced by leptin in different in vitro systems based on cells from the reproductive tract, suggest that leptin is involved in a large array of regulatory actions required for normal reproductive functions.…”

Section: Introductionmentioning

confidence: 99%

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Leptin receptor expression and in vitro leptin actions on prostaglandin release and nitric oxide synthase activity in the rabbit oviduct

Zerani¹,

Boiti²,

Dall’Aglio³

et al. 2005

Journal of Endocrinology

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In this study, we have examined the presence and the distribution of receptors for leptin (Ob-R) in the oviduct of rabbits, and the effects of leptin on the release of prostaglandin (PG) F2 and PGE2 and on the activity of nitric oxide (NO) synthase (NOS) by oviducts cultured in vitro. Rabbits were killed during the follicular phase and the oviducts were incubated in vitro with leptin, PGF2 , PGE2, NO donor and inhibitors of NOS and cyclooxigenase (COX). Using immunohistochemistry, Ob-Rlike positive reaction was observed only in the cytoplasm of secretory cells, having stronger intensity in the infundibulum and ampulla tracts than in the isthmus. Both leptin and NO donor inhibited PGE2 release, whereas they enhanced PGF2 release; NOS inhibitor alone or with leptin increased PGE2 and decreased PGF2 production; NOS activity was enhanced by leptin, while PGs did not affect this enzyme. This study suggests that the oviduct could be a potential target for endocrine regulation by leptin, whose circulating levels may act as a metabolic signal modulating oviductal PG release through mediation of the NOS/NO system.

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Section: Discussionsupporting

confidence: 94%

Section: Discussionmentioning

confidence: 58%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Leptin receptor expression and in vitro leptin actions on prostaglandin release and nitric oxide synthase activity in the rabbit oviduct

Zerani¹,

Boiti²,

Dall’Aglio³

et al. 2005

Journal of Endocrinology

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“…The brain could monitor adipocyte function via sensory innervation of adipose tissue (34). Adipose tissue can also communicate with the brain through changes in circulating leptin levels because adipocyte leptin production responds to changes in substrate oxidation (35)(36)(37).…”

Section: Discussionmentioning

confidence: 99%

Effect of Food Restriction and Intense Physical Training on Estrous Cyclicity and Plasma Leptin Concentrations in Rats

Santos

Silva

Bacurau

et al. 2011

J Nutr Sci Vitaminol

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SummaryIntense physical training and dietary energy restriction have been associated with consequences such as nutritional amenorrhea. We investigated the effects of intense physical training, food restriction or the combination of both strategies on estrous cyclicity in female rats, and the relationship between leptin ad these effects. Twenty-seven female Wistar rats were distributed into four groups: SF: sedentary, fed ad libitum; SR: sedentary subjected to 50% food restriction (based on the food intake of their fed counterparts); TF: trained (physical training on a motor treadmill with a gradual increase in speed and time), fed ad libitum; TR: trained with 50% food restriction. We analysed estrous cyclicity, plasma leptin and estradiol as well as chemical composition of the carcass, body weight variation, and weight of ovaries and perirenal adipose tissue. Data demonstrate that physical training alone was not responsible for significant modifications in either carcass chemical composition or reproductive function. Food restriction reduced leptin levels in all animals and interrupted the estrous cyclicity in some animals, but only the combination of food restriction and physical training was capable of interrupting the estrous cyclicity in all animals. Leptin was not directly related to estrous cyclicity. From our findings, it may be concluded that there is an additive or synergistic effect of energy intake restriction and energy expenditure by intense physical training on estrous cyclicity. Leptin appears to be one among others factors related to estrous cycle, but it probably acts indirectly. Key Words energy intake, body composition, estrous cycle, leptin, physical exercise Some female athletes are constantly under pressure to achieve and/or to maintain low body weight, leading to potentially harmful patterns of restricted dieting and over exercising. Some of the health consequences of long-term energy restriction include poor nutritional status and risk of exercise-induced amenorrhea ( 1 , 2 ). In humans, this condition is characterized by the absence of menstruation for 90 d or more.Based on epidemiological data, Frisch ( 3 ) reported that, in women and girls, body fat content and ovulatory cyclicity were positively associated. However, one or more main signals that centrally indicates the availability of energy is still unknown ( 4 ). Since physical activity may reduce leptin mRNA expression ( 5 , 6 ) and athletes that train intensively, under restricted calorie intake, present a higher percentage of amenorrhea than sedentary women ( 7 ), it may be speculated that leptin is involved in the transduction of the energy availability signals.Studies on the effects of exercise, reproductive function and leptin response have been hindered by the inability to disassociate the effects of exercise itself from other confusing factors. These factors could be related to energy intake below the requirements or different hormones involved ( 8 , 9 ). It is not clear whether the reproductive functions are interrupted due...

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“…In rabbits, leptin receptor (Ob-R) has been detected in endometrial cells (Gonzalez & Leavis, 2003) and the ovary at day 9 of pseudo-pregnancy by immunohistochemistry and Western blot analysis that supports a permissive luteolytic role for leptin in rabbit Corpus luteum (Zerani et al, 2004). Recently, Koch et al (2013) identified the leptin gene cloning and expression in the rabbit mammary epithelial cells during pregnancy and lactation.…”

Section: Introductionmentioning

confidence: 88%

Leptin Gene Expression in Rabbits During Pregnancy and Fetal Life

Kirat¹,

Hamid²,

Mohamed³

et al. 2015

IJB

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Leptin may act as the critical link between adipose tissue and reproduction. Although considerable progress has been achieved in understanding the reproductive actions of leptin, much work is needed for understanding its physiological role. Till now, no data has been published about the distribution and expression levels of leptin in the rabbit maternal adipose tissue, placenta, and various fetal rabbit tissues during pregnancy and postpartum. Our results indicated that circulating leptin levels in rabbit serum during pregnancy were significantly higher than in postpartum and non pregnant rabbits. Furthermore, leptin showed positive correlations with body weight and estrogen and negative correlation with progesterone in pregnant and postpartum rabbits. RT-PCR verified the presence of RNAs encoding leptin in the rabbit maternal perirenal adipose tissue, placenta, and several fetal tissues; including brain, liver, adipose tissue, and bone. The relative abundance of leptin RNA in rabbit maternal adipose was significantly higher at 20 th day of pregnancy than that of non pregnant rabbits, while it was significantly decreased at 2 nd day after parturition. No significant changes in the placental leptin RNA levels were noticed in pregnant rabbits at 10 th , 20 th , and 30 th day of pregnancy. The relative abundance of fetal leptin transcripts at day 30 th of pregnancy was in the order of liver> bone ≥ adipose tissue > brain. The present study provides new evidence for the distribution and expression levels of leptin in the rabbit maternal and fetal tissues during pregnancy and supports the importance of leptin in reproductive physiology and fetal development.

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Ob receptor in rabbit ovary and leptin in vitro regulation of corpora lutea

Cited by 62 publications

References 56 publications

Leptin receptor expression and in vitro leptin actions on prostaglandin release and nitric oxide synthase activity in the rabbit oviduct

Leptin receptor expression and in vitro leptin actions on prostaglandin release and nitric oxide synthase activity in the rabbit oviduct

Effect of Food Restriction and Intense Physical Training on Estrous Cyclicity and Plasma Leptin Concentrations in Rats

Leptin Gene Expression in Rabbits During Pregnancy and Fetal Life

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