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Nakao K, Iwata K, Takeshita T, Ozawa H. Expression of hypothalamic kisspeptin, neurokinin B, and dynorphin A neurons attenuates in female Zucker fatty rats. Neurosci Lett 2017; 665:135-139. [PMID: 29203206 DOI: 10.1016/j.neulet.2017.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 11/25/2017] [Accepted: 12/01/2017] [Indexed: 10/18/2022]
Abstract
Zucker fatty (ZF) rats are considered to be an obese model due to leptin receptor abnormality and such rats show infertility. Pulsatile gonadotropin-releasing hormone/luteinizing hormone (LH) secretion, which is important for follicular development in females, is considered to be controlled by KNDy neurons coexpressing kisspeptin, neurokinin B (NKB), and dynorphin A (DynA), encoded by Kiss1, Tac3, and Pdyn, respectively, in the hypothalamic arcuate nucleus (ARC). The purpose of this study is to examine the expression of KNDy neurons in female ZF rats by histochemical approach because pulsatile LH secretion is suppressed. Zucker lean (ZL) rats served as a control group. Animals were ovariectomized and subcutaneously implanted with a silicon tube containing estradiol to produce plasma level of estradiol during diestrus. Plasma LH levels decreased in ZF rats compared with ZL rats. The expressions of each mRNA (Kiss1, Tac3, and Pdyn) and each peptide (kisspeptin, NKB, and DynA) in the ARC significantly decreased in ZF rats compared with ZL rats. However, the number of Kiss1 neurons in the anterior ventral periventricular nucleus did not significantly differ between the two groups. These results suggest that dysfunction of leptin signaling negatively affects KNDy neurons in the ARC, resulting in reproductive dysfunction caused by suppression of the LH pulse.
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Affiliation(s)
- Kimihiko Nakao
- Department of Reproductive Medicine, Perinatology and Gynecologic Oncology, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo 113-8602, Japan
| | - Kinuyo Iwata
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo 113-8602, Japan
| | - Toshiyuki Takeshita
- Department of Reproductive Medicine, Perinatology and Gynecologic Oncology, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo 113-8602, Japan
| | - Hitoshi Ozawa
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo 113-8602, Japan.
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Volk KM, Pogrebna VV, Roberts JA, Zachry JE, Blythe SN, Toporikova N. High-Fat, High-Sugar Diet Disrupts the Preovulatory Hormone Surge and Induces Cystic Ovaries in Cycling Female Rats. J Endocr Soc 2017; 1:1488-1505. [PMID: 29308444 PMCID: PMC5740526 DOI: 10.1210/js.2017-00305] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 10/30/2017] [Indexed: 12/16/2022] Open
Abstract
Diet-induced obesity has been associated with various metabolic and reproductive disorders, including polycystic ovary syndrome. However, the mechanisms by which obesity influences the reproductive system are still not fully known. Studies have suggested that impairments in hormone signaling are associated with the development of symptoms such as acyclicity and ovarian cysts. However, these studies have often failed to address how these hormonal changes arise and how they might contribute to the progression of reproductive diseases. In the present study, we used a high-fat, high-sugar (HFHS) diet to induce obesity in a female rodent model to determine the changes in critical reproductive hormones that might contribute to the development of irregular estrous cycling and reproductive cycle termination. The HFHS animals exhibited impaired estradiol, progesterone (P4), and luteinizing hormone (LH) surges before ovulation. The HFHS diet also resulted in altered basal levels of testosterone (T) and LH. Furthermore, alterations in the basal P4/T ratio correlated strongly with ovarian cyst formation in HFHS rats. Thus, this model provides a method to assess the underlying etiology of obesity-related reproductive dysfunction and to examine an acyclic reproductive phenotype as it develops.
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Affiliation(s)
- Katrina M. Volk
- Neuroscience Program, Washington and Lee University, Lexington, Virginia 24450
| | | | - Jackson A. Roberts
- Neuroscience Program, Washington and Lee University, Lexington, Virginia 24450
| | - Jennifer E. Zachry
- Neuroscience Program, Washington and Lee University, Lexington, Virginia 24450
| | - Sarah N. Blythe
- Neuroscience Program, Washington and Lee University, Lexington, Virginia 24450
- Department of Biology, Washington and Lee University, Lexington, Virginia 24450
| | - Natalia Toporikova
- Neuroscience Program, Washington and Lee University, Lexington, Virginia 24450
- Department of Biology, Washington and Lee University, Lexington, Virginia 24450
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Lee HS, Yoon JS, Hwang JS. Luteinizing Hormone Secretion during Gonadotropin-Releasing Hormone Stimulation Tests in Obese Girls with Central Precocious Puberty. J Clin Res Pediatr Endocrinol 2016; 8:392-398. [PMID: 27215137 PMCID: PMC5197996 DOI: 10.4274/jcrpe.3091] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE Girls with precocious puberty have high luteinizing hormone (LH) levels and advanced bone age. Obese children enter puberty at earlier ages than do non-obese children. We analyzed the effects of obesity on LH secretion during gonadotropin-releasing hormone (GnRH) tests in girls with precocious puberty. METHODS A total of 981 subjects with idiopathic precocious puberty who had undergone a GnRH stimulation testing between 2008 and 2014 were included in the study. Subjects were divided into three groups based on body mass index (BMI). Auxological data and gonadotropin levels after the GnRH stimulation test were compared. RESULTS In Tanner stage 2 girls, peak stimulated LH levels on GnRH test were 11.9±7.5, 10.4±6.4, and 9.1±6.1 IU/L among normal-weight, overweight, and obese subjects, respectively (p=0.035 for all comparisons). In Tanner stage 3 girls, peak stimulated LH levels were 14.9±10.9, 12.8±7.9, and 9.6±6.0 IU/L, respectively (p=0.022 for all comparisons). However, in Tanner stage 4 girls, peak stimulated LH levels were not significantly different among normal, overweight, and obese children. On multivariate analysis, BMI standard deviation score was significantly and negatively associated with peak LH (β=-1.178, p=0.001). CONCLUSION In girls with central precocious puberty, increased BMI was associated with slightly lower peak stimulated LH levels at early pubertal stages (Tanner stages 2 and 3). This association was not valid in Tanner stage 4 girls.
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Affiliation(s)
- Hae Sang Lee
- Ajou University School of Medicine, Ajou University Hospital, Department of Pediatrics, Suwon, Korea
| | - Jong Seo Yoon
- Ajou University School of Medicine, Ajou University Hospital, Department of Pediatrics, Suwon, Korea
| | - Jin Soon Hwang
- Ajou University School of Medicine, Ajou University Hospital, Department of Pediatrics, Suwon, Korea, Phone: 82-31-219-5166 E-mail:
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Ma X, Hayes E, Prizant H, Srivastava RK, Hammes SR, Sen A. Leptin-Induced CART (Cocaine- and Amphetamine-Regulated Transcript) Is a Novel Intraovarian Mediator of Obesity-Related Infertility in Females. Endocrinology 2016; 157:1248-57. [PMID: 26730935 PMCID: PMC4769362 DOI: 10.1210/en.2015-1750] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 12/29/2015] [Indexed: 12/24/2022]
Abstract
Obesity is considered detrimental to women's reproductive health. Although most of the attention has been focused on the effects of obesity on hypothalamic function, studies suggest a multifactorial impact. In fact, obesity is associated with reduced fecundity even in women with regular cycles, indicating that there may be local ovarian effects modulating fertility. Here we describe a novel mechanism for leptin actions directly in the ovary that may account for some of the negative effects of obesity on ovarian function. We find that normal cycling, obese, hyperleptinemic mice fed with a high-fat diet are subfertile and ovulate fewer oocytes compared with animals fed with a normal diet. Importantly, we show that leptin induces expression of the neuropeptide cocaine- and amphetamine-regulated transcript (CART) in the granulosa cells (GCs) of ovarian follicles both in vitro and in vivo. CART then negatively affects intracellular cAMP levels, MAPK signaling, and aromatase mRNA expression, which leads to lower estradiol synthesis in GCs and altered ovarian folliculogenesis. Finally, in human samples from patients undergoing in vitro fertilization, we show a significant positive correlation between patient body mass index, CART mRNA expression in GCs, and CART peptide levels in follicular fluid. These observations suggest that, under obese conditions, CART acts as a local mediator of leptin in the ovary to cause ovarian dysfunction and reduced fertility.
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Affiliation(s)
- Xiaoting Ma
- Division of Endocrinology and Metabolism (X.M., E.H., H.P., S.R.H., A.S.), Department of Medicine, and Department of Obstetrics and Gynecology (R.K.S.), University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Emily Hayes
- Division of Endocrinology and Metabolism (X.M., E.H., H.P., S.R.H., A.S.), Department of Medicine, and Department of Obstetrics and Gynecology (R.K.S.), University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Hen Prizant
- Division of Endocrinology and Metabolism (X.M., E.H., H.P., S.R.H., A.S.), Department of Medicine, and Department of Obstetrics and Gynecology (R.K.S.), University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Rajesh K Srivastava
- Division of Endocrinology and Metabolism (X.M., E.H., H.P., S.R.H., A.S.), Department of Medicine, and Department of Obstetrics and Gynecology (R.K.S.), University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Stephen R Hammes
- Division of Endocrinology and Metabolism (X.M., E.H., H.P., S.R.H., A.S.), Department of Medicine, and Department of Obstetrics and Gynecology (R.K.S.), University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Aritro Sen
- Division of Endocrinology and Metabolism (X.M., E.H., H.P., S.R.H., A.S.), Department of Medicine, and Department of Obstetrics and Gynecology (R.K.S.), University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
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Al-Safi ZA, Liu H, Carlson NE, Chosich J, Harris M, Bradford AP, Robledo C, Eckel RH, Polotsky AJ. Omega-3 Fatty Acid Supplementation Lowers Serum FSH in Normal Weight But Not Obese Women. J Clin Endocrinol Metab 2016; 101:324-33. [PMID: 26523525 PMCID: PMC4701838 DOI: 10.1210/jc.2015-2913] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
CONTEXT Dietary omega-3 fatty acids delay ovarian aging and promote oocyte quality in mice. OBJECTIVE To test whether dietary supplementation with omega-3 polyunsaturated fatty acids (PUFA) modulates reproductive hormones in reproductive-age women. DESIGN Prospective interventional study. SETTING Academic center. PARTICIPANTS Fifteen obese and 12 normal-weight (NW) eumenorrheic women, ages 28-34 years. INTERVENTION Two frequent blood-sampling studies were performed before and after 1 month of omega-3 PUFA supplementation with 4 g of eicosapentaenoic acid and docosahexaenoic acid daily. MAIN OUTCOME MEASURES Serum LH and FSH (basal and after GnRH stimulation). RESULTS The ratio of omega-6 to omega-3 PUFA was significantly reduced in plasma and red blood cell components for both groups after treatment (both P < .01). Omega-3 PUFA supplementation resulted in reduction of FSH and FSH response to GnRH by 17% on average (P = .06 and P = .03, respectively) in NW but not obese women. Serum levels of IL-1β and TNF-α were reduced after omega-3 PUFA supplementation (-72% for IL-1β; -56% for TNF-α; both, P < .05) in obese but not in NW women. This reduction, however, was not associated with a hormonal change in obese women. CONCLUSIONS Dietary administration with omega-3 PUFA decreased serum FSH levels in NW but not in obese women with normal ovarian reserve. This effect is intriguing and is directionally consistent with murine data whereby higher dietary omega-3 PUFA extends reproductive lifespan. Our results imply that this nutritional intervention should be tested in women with diminished ovarian reserve in an attempt to delay ovarian aging.
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Affiliation(s)
- Zain A Al-Safi
- Department of Obstetrics and Gynecology (Z.A.A., J.C., A.P.B., C.R., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C.), Colorado School of Public Health, Aurora, Colorado 80045; Department of Food Science and Human Nutrition (M.H.), Colorado State University, Fort Collins, Colorado 80523; and Department of Medicine (R.H.E.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Huayu Liu
- Department of Obstetrics and Gynecology (Z.A.A., J.C., A.P.B., C.R., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C.), Colorado School of Public Health, Aurora, Colorado 80045; Department of Food Science and Human Nutrition (M.H.), Colorado State University, Fort Collins, Colorado 80523; and Department of Medicine (R.H.E.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Nichole E Carlson
- Department of Obstetrics and Gynecology (Z.A.A., J.C., A.P.B., C.R., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C.), Colorado School of Public Health, Aurora, Colorado 80045; Department of Food Science and Human Nutrition (M.H.), Colorado State University, Fort Collins, Colorado 80523; and Department of Medicine (R.H.E.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Justin Chosich
- Department of Obstetrics and Gynecology (Z.A.A., J.C., A.P.B., C.R., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C.), Colorado School of Public Health, Aurora, Colorado 80045; Department of Food Science and Human Nutrition (M.H.), Colorado State University, Fort Collins, Colorado 80523; and Department of Medicine (R.H.E.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Mary Harris
- Department of Obstetrics and Gynecology (Z.A.A., J.C., A.P.B., C.R., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C.), Colorado School of Public Health, Aurora, Colorado 80045; Department of Food Science and Human Nutrition (M.H.), Colorado State University, Fort Collins, Colorado 80523; and Department of Medicine (R.H.E.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Andrew P Bradford
- Department of Obstetrics and Gynecology (Z.A.A., J.C., A.P.B., C.R., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C.), Colorado School of Public Health, Aurora, Colorado 80045; Department of Food Science and Human Nutrition (M.H.), Colorado State University, Fort Collins, Colorado 80523; and Department of Medicine (R.H.E.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Celeste Robledo
- Department of Obstetrics and Gynecology (Z.A.A., J.C., A.P.B., C.R., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C.), Colorado School of Public Health, Aurora, Colorado 80045; Department of Food Science and Human Nutrition (M.H.), Colorado State University, Fort Collins, Colorado 80523; and Department of Medicine (R.H.E.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Robert H Eckel
- Department of Obstetrics and Gynecology (Z.A.A., J.C., A.P.B., C.R., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C.), Colorado School of Public Health, Aurora, Colorado 80045; Department of Food Science and Human Nutrition (M.H.), Colorado State University, Fort Collins, Colorado 80523; and Department of Medicine (R.H.E.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Alex J Polotsky
- Department of Obstetrics and Gynecology (Z.A.A., J.C., A.P.B., C.R., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C.), Colorado School of Public Health, Aurora, Colorado 80045; Department of Food Science and Human Nutrition (M.H.), Colorado State University, Fort Collins, Colorado 80523; and Department of Medicine (R.H.E.), University of Colorado School of Medicine, Aurora, Colorado 80045
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Al-Safi ZA, Liu H, Carlson NE, Chosich J, Lesh J, Robledo C, Bradford AP, Gee NA, Phang T, Santoro N, Kohrt W, Polotsky AJ. Estradiol Priming Improves Gonadotrope Sensitivity and Pro-Inflammatory Cytokines in Obese Women. J Clin Endocrinol Metab 2015; 100:4372-81. [PMID: 26425884 PMCID: PMC4702462 DOI: 10.1210/jc.2015-1946] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Obesity is associated with a pro-inflammatory state and relative hypogonadotropic hypogonadism. Estrogen (E2) is a potential link between these phenomena because it exhibits negative feedback on gonadotropin secretion and also inhibits production of pro-inflammatory cytokines. OBJECTIVE We sought to examine the effect of estrogen priming on the hypothalamic-pituitary-ovarian axis in obesity. DESIGN, SETTING, AND PARTICIPANTS This was an interventional study at an academic center of 11 obese and 10 normal-weight (NW) women. INTERVENTION A frequent blood-sampling study and one month of daily urinary collection were performed before and after administration of transdermal estradiol 0.1 mg/d for one entire menstrual cycle. MAIN OUTCOME MEASURES Serum LH and FSH before and after GnRH stimulation, and urinary estrogen and progesterone metabolites were measured. RESULTS E2 increased LH pulse amplitude and FSH response to GnRH (P = .048, and P < .03, respectively) in obese but not NW women. After E2 priming, ovulatory obese but not NW women had a 25% increase in luteal progesterone (P = .01). Obese women had significantly higher baseline IL-6, IL-10, TGF-β, and IL-12 compared with NW (all P < .05); these levels were reduced after E2 (-6% for IL-1β, -21% for IL-8, -5% for TGF-β, -5% for IL-12; all P < .05) in obese but not in NW women. CONCLUSIONS E2 priming seems to improve hypothalamic-pituitary-ovarian axis function and systemic inflammation in ovulatory, obese women. Reducing chronic inflammation at the pituitary level may decrease the burden of obesity on fertility.
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Affiliation(s)
- Zain A Al-Safi
- Department of Obstetrics and Gynecology (Z.A.A., J.C., J.L., C.R., A.P.B., N.S., W.K., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C., T.P.), Colorado School of Public Health, Aurora, Colorado 80045; Center for Health and the Environment and California National Primate Research Center (N.A.G.), University of California, Davis, California 95616; and Department of Medicine (W.K.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Huayu Liu
- Department of Obstetrics and Gynecology (Z.A.A., J.C., J.L., C.R., A.P.B., N.S., W.K., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C., T.P.), Colorado School of Public Health, Aurora, Colorado 80045; Center for Health and the Environment and California National Primate Research Center (N.A.G.), University of California, Davis, California 95616; and Department of Medicine (W.K.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Nichole E Carlson
- Department of Obstetrics and Gynecology (Z.A.A., J.C., J.L., C.R., A.P.B., N.S., W.K., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C., T.P.), Colorado School of Public Health, Aurora, Colorado 80045; Center for Health and the Environment and California National Primate Research Center (N.A.G.), University of California, Davis, California 95616; and Department of Medicine (W.K.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Justin Chosich
- Department of Obstetrics and Gynecology (Z.A.A., J.C., J.L., C.R., A.P.B., N.S., W.K., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C., T.P.), Colorado School of Public Health, Aurora, Colorado 80045; Center for Health and the Environment and California National Primate Research Center (N.A.G.), University of California, Davis, California 95616; and Department of Medicine (W.K.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Jennifer Lesh
- Department of Obstetrics and Gynecology (Z.A.A., J.C., J.L., C.R., A.P.B., N.S., W.K., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C., T.P.), Colorado School of Public Health, Aurora, Colorado 80045; Center for Health and the Environment and California National Primate Research Center (N.A.G.), University of California, Davis, California 95616; and Department of Medicine (W.K.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Celeste Robledo
- Department of Obstetrics and Gynecology (Z.A.A., J.C., J.L., C.R., A.P.B., N.S., W.K., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C., T.P.), Colorado School of Public Health, Aurora, Colorado 80045; Center for Health and the Environment and California National Primate Research Center (N.A.G.), University of California, Davis, California 95616; and Department of Medicine (W.K.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Andrew P Bradford
- Department of Obstetrics and Gynecology (Z.A.A., J.C., J.L., C.R., A.P.B., N.S., W.K., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C., T.P.), Colorado School of Public Health, Aurora, Colorado 80045; Center for Health and the Environment and California National Primate Research Center (N.A.G.), University of California, Davis, California 95616; and Department of Medicine (W.K.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Nancy A Gee
- Department of Obstetrics and Gynecology (Z.A.A., J.C., J.L., C.R., A.P.B., N.S., W.K., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C., T.P.), Colorado School of Public Health, Aurora, Colorado 80045; Center for Health and the Environment and California National Primate Research Center (N.A.G.), University of California, Davis, California 95616; and Department of Medicine (W.K.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Tzu Phang
- Department of Obstetrics and Gynecology (Z.A.A., J.C., J.L., C.R., A.P.B., N.S., W.K., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C., T.P.), Colorado School of Public Health, Aurora, Colorado 80045; Center for Health and the Environment and California National Primate Research Center (N.A.G.), University of California, Davis, California 95616; and Department of Medicine (W.K.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Nanette Santoro
- Department of Obstetrics and Gynecology (Z.A.A., J.C., J.L., C.R., A.P.B., N.S., W.K., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C., T.P.), Colorado School of Public Health, Aurora, Colorado 80045; Center for Health and the Environment and California National Primate Research Center (N.A.G.), University of California, Davis, California 95616; and Department of Medicine (W.K.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Wendy Kohrt
- Department of Obstetrics and Gynecology (Z.A.A., J.C., J.L., C.R., A.P.B., N.S., W.K., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C., T.P.), Colorado School of Public Health, Aurora, Colorado 80045; Center for Health and the Environment and California National Primate Research Center (N.A.G.), University of California, Davis, California 95616; and Department of Medicine (W.K.), University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Alex J Polotsky
- Department of Obstetrics and Gynecology (Z.A.A., J.C., J.L., C.R., A.P.B., N.S., W.K., A.J.P.), University of Colorado School of Medicine, Aurora, Colorado 80045; Department of Biostatistics and Informatics (H.L., N.E.C., T.P.), Colorado School of Public Health, Aurora, Colorado 80045; Center for Health and the Environment and California National Primate Research Center (N.A.G.), University of California, Davis, California 95616; and Department of Medicine (W.K.), University of Colorado School of Medicine, Aurora, Colorado 80045
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Candlish M, Angelis RD, Götz V, Boehm U. Gene Targeting in Neuroendocrinology. Compr Physiol 2015; 5:1645-76. [DOI: 10.1002/cphy.c140079] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Sharma S, Morinaga H, Hwang V, Fan W, Fernandez MO, Varki N, Olefsky JM, Webster NJG. Free fatty acids induce Lhb mRNA but suppress Fshb mRNA in pituitary LβT2 gonadotropes and diet-induced obesity reduces FSH levels in male mice and disrupts the proestrous LH/FSH surge in female mice. Endocrinology 2013; 154:2188-99. [PMID: 23525221 PMCID: PMC3740488 DOI: 10.1210/en.2012-2218] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Female obesity is associated with insulin resistance, hyperandrogenemia, and reproductive dysfunction. We hypothesized that elevated free fatty acids (FFAs) might directly modulate pituitary gonadotropin production. FFAs caused a time- and dose-dependent increase in phosphorylation of the MAPKs p38MAPK, c-Jun N-terminal kinase (JNK)-1/2, and ERK1/2 in LβT2 gonadotrope cells. Furthermore, FFAs up-regulated Lhb mRNA expression acutely, an effect that was blocked by JNK inhibition, but suppressed Fshb mRNA expression, an effect that was independent of MAPK signaling. FFAs enhanced the activation of the MAPKs in the presence of GnRH, although the cotreatment did not alter Lhb induction but did eliminate the GnRH induction of Fshb. FFAs also suppressed activin-induced Fshb expression. Knockdown experiments showed that the FFA effect on the inflammatory kinases p38MAPK and JNK and on Lhb, but not Fshb, mRNA expression is mediated via toll-like receptor-2 and toll-like receptor-4 and was mimicked by lipopolysaccharide stimulation. In vivo, male C57BL/6 mice on a high-fat diet showed reduced FSH levels consistent with the suppression of Fshb seen in vitro. Histological analysis of the testes showed an increased number of abnormal seminiferous tubules. Female mice on a high-fat diet lacked the expected proestrus LH and FSH surge and exhibited an increase in the number of days at estrus and a reduced number of days at proestrus, and ovaries had significantly fewer corpora lutea. Taken together, our findings suggest that lipid excess can lead to reproductive defects in both male and female mice.
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MESH Headings
- Animals
- Diet, High-Fat/adverse effects
- Dose-Response Relationship, Drug
- Fatty Acids, Nonesterified/pharmacology
- Female
- Follicle Stimulating Hormone, beta Subunit/blood
- Follicle Stimulating Hormone, beta Subunit/genetics
- Follicle Stimulating Hormone, beta Subunit/metabolism
- Gene Expression/drug effects
- Gonadotrophs/cytology
- Gonadotrophs/drug effects
- Gonadotrophs/metabolism
- Immunoblotting
- Luteinizing Hormone, beta Subunit/blood
- Luteinizing Hormone, beta Subunit/genetics
- Luteinizing Hormone, beta Subunit/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mitogen-Activated Protein Kinases/metabolism
- Obesity/etiology
- Obesity/genetics
- Obesity/metabolism
- Ovary/drug effects
- Ovary/metabolism
- Pituitary Gland/cytology
- Proestrus/drug effects
- Proestrus/genetics
- Proestrus/metabolism
- RNA Interference
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Toll-Like Receptor 2/genetics
- Toll-Like Receptor 2/metabolism
- Toll-Like Receptor 4/genetics
- Toll-Like Receptor 4/metabolism
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Affiliation(s)
- Shweta Sharma
- Medical Research Service, Veterans Affairs San Diego Healthcare System, San Diego California 92161, USA
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9
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True C, Kirigiti MA, Kievit P, Grove KL, Smith MS. Leptin is not the critical signal for kisspeptin or luteinising hormone restoration during exit from negative energy balance. J Neuroendocrinol 2011; 23:1099-112. [PMID: 21518032 PMCID: PMC3646420 DOI: 10.1111/j.1365-2826.2011.02144.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Low levels of the adipocyte hormone leptin are considered to be the key signal contributing to inhibited gonadotrophin-releasing hormone (GnRH) release and reproductive acyclicity during negative energy balance. Hypoleptinaemia-induced inhibition of GnRH may be initiated with upstream inhibition of the secretagogue kisspeptin (Kiss1) because GnRH neurones do not express leptin receptors. The present study aimed to determine whether eliminating the hypoleptinaemia associated with caloric restriction (CR), by restoring leptin to normal basal levels, could reverse the suppression of the reproductive neuroendocrine axis. Fifty percent CR resulted in significant suppression of anteroventral periventricular Kiss1 mRNA, arcuate nucleus (ARH) Kiss1 and neurokinin B (NKB) mRNA levels and serum luteinising hormone (LH). Restoring leptin to normal basal levels did not restore Kiss1 or NKB mRNA or LH levels. Surprisingly, leptin did not activate expression of phosphorylated signal-transducer and activator of transcription-3 in ARC Kiss1 neurones, indicating that these neurones may not relay leptin signalling to GnRH neurones. Previous work in fasting models showing restoration of LH used a pharmacological dose of leptin. Therefore, in a 48-h fast study, replacement of leptin to pharmacological levels was compared with replacement of leptin to normal basal levels. Maintaining leptin at normal basal levels during the fast did not prevent inhibition of LH. By contrast, pharmacological levels of leptin did maintain LH at control values. These results suggest that, although leptin may be a permissive signal for reproductive function, hypoleptinaemia is unlikely to be the critical signal responsible for ARC Kiss1 and LH inhibition during negative energy balance.
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Affiliation(s)
- C True
- Oregon National Primate Research Center, Division of Neuroscience, Oregon Health & Science University, Beaverton, OR 97006, USA
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10
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Quennell JH, Howell CS, Roa J, Augustine RA, Grattan DR, Anderson GM. Leptin deficiency and diet-induced obesity reduce hypothalamic kisspeptin expression in mice. Endocrinology 2011; 152:1541-50. [PMID: 21325051 PMCID: PMC3206710 DOI: 10.1210/en.2010-1100] [Citation(s) in RCA: 223] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The hormone leptin modulates a diverse range of biological functions, including energy homeostasis and reproduction. Leptin promotes GnRH function via an indirect action on forebrain neurons. We tested whether leptin deficiency or leptin resistance due to a high-fat diet (HFD) can regulate the potent reproductive neuropeptide kisspeptin. In mice with normalized levels of estradiol, leptin deficiency markedly reduced kisspeptin gene expression, particularly in the arcuate nucleus (ARC), and kisspeptin immunoreactive cell numbers in the rostral periventricular region of the third ventricle (RP3V). The HFD model was used to determine the effects of diet-induced obesity and central leptin resistance on kisspeptin cell number and gene expression. DBA/2J mice, which are prone to HFD-induced infertility, showed a marked decrease in kisspeptin expression in both the RP3V and ARC and cell numbers in the RP3V after HFD. This is the first evidence that kisspeptin can be regulated by HFD and/or increased body weight. Next we demonstrated that leptin does not signal (via signal transducer and activator of transcription 3 or 5, or mammalian target of rapamycin) directly on kisspeptin-expressing neurons in the RP3V. Lastly, in leptin receptor-deficient mice, neither GnRH nor kisspeptin neurons were activated during a preovulatory-like GnRH/LH surge induction regime, indicating that leptin's actions on GnRH may be upstream of kisspeptin neurons. These data provide evidence that leptin's effects on reproductive function are regulated by kisspeptin neurons in both the ARC and RP3V, although in the latter site the effects are likely to be indirect.
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Affiliation(s)
- Janette H Quennell
- Centre for Neuroendocrinology and Department of Anatomy and Structural Biology, University of Otago School of Medical Sciences, PO Box 913, Dunedin 9054, New Zealand.
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11
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True C, Grove KL, Smith MS. Beyond Leptin: Emerging Candidates for the Integration of Metabolic and Reproductive Function during Negative Energy Balance. Front Endocrinol (Lausanne) 2011; 2:53. [PMID: 22645510 PMCID: PMC3355832 DOI: 10.3389/fendo.2011.00053] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 09/29/2011] [Indexed: 12/19/2022] Open
Abstract
Reproductive status is tightly coupled to metabolic state in females, and ovarian cycling in mammals is halted when energy output exceeds energy input, a metabolic condition known as negative energy balance. This inhibition of reproductive function during negative energy balance occurs due to suppression of gonadotropin-releasing hormone (GnRH) release in the hypothalamus. The GnRH secretagogue kisspeptin is also inhibited during negative energy balance, indicating that inhibition of reproductive neuroendocrine circuits may occur upstream of GnRH itself. Understanding the metabolic signals responsible for the inhibition of reproductive pathways has been a compelling research focus for many years. A predominant theory in the field is that the status of energy balance is conveyed to reproductive neuroendocrine circuits via the adipocyte hormone leptin. Leptin is stimulatory for GnRH release and lower levels of leptin during negative energy balance are believed to result in decreased stimulatory drive for GnRH cells. However, recent evidence found that restoring leptin to physiological levels did not restore GnRH function in three different models of negative energy balance. This suggests that although leptin may be an important permissive signal for reproductive function as indicated by many years of research, factors other than leptin must critically contribute to negative energy balance-induced reproductive inhibition. This review will focus on emerging candidates for the integration of metabolic status and reproductive function during negative energy balance.
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Affiliation(s)
- Cadence True
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science UniversityBeaverton, OR, USA
| | - Kevin L. Grove
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science UniversityBeaverton, OR, USA
| | - M. Susan Smith
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science UniversityBeaverton, OR, USA
- *Correspondence: M. Susan Smith, Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA. e-mail:
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12
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Del Bianco-Borges B, Cabral FJ, Franci CR. Co-expression of leptin and oestrogen receptors in the preoptic-hypothalamic area. J Neuroendocrinol 2010; 22:996-1003. [PMID: 20584107 DOI: 10.1111/j.1365-2826.2010.02046.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The interaction between the reproductive axis and energy balance suggests that leptin acts as a possible mediator. This hormone acts in the regulation of metabolism, feeding behaviour and reproduction. Animals homozygous for the gene 'ob' (ob/ob) are obese and infertile, and these effects are reversed after systemic administration of leptin. Thus, the present study aimed to determine: (i) whether cells that express leptin also express oestrogen receptors of type-alpha (ER-alpha) or -beta (ER-beta) in the medial preoptic area (MPOA) and in the arcuate (ARC), dorsomedial (DMH) and ventromedial hypothalamic nucleus and (ii) whether there is change in the gene and protein expression of leptin in these brain areas in ovariectomised (OVX) animals when oestrogen-primed. Wistar female rats with normal oestrous cycles or ovariectomised oestrogen-primed or vehicle (oil)-primed were utilised. To determine whether there was a co-expression, immunofluorescence was utilised for double staining. Confocal microscopy was used to confirm the co-expression. The technique of real-time polymerase chain reaction and western blotting were employed to analyse gene and protein expression, respectively. The results obtained showed co-expression of leptin and ER-alpha in the MPOA and in the DMH, as well as leptin and ER-beta in the MPOA, DMH and ARC. However, we did not detect leptin in the MPOA, ARC and DMH using western blotting and there was no statistical difference in leptin gene expression in the MPOA, DMH, ARC, pituitary or adipose tissue between OVX rats treated with oestrogen or vehicle. In conclusion, the results obtained in the present study confirm that the brain is also a source of leptin and reveal co-expression of oestrogen receptors and leptin in the same cells from areas related to reproductive function and feeding behaviour. Although these data corroborate the previous evidence obtained concerning the interaction between the action of brain leptin and reproductive function, the physiological relevance of this interaction remains uncertain and additional studies are necessary to elucidate the exact role of central leptin.
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Affiliation(s)
- B Del Bianco-Borges
- Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
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13
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Navratil AM, Song H, Hernandez JB, Cherrington BD, Santos SJ, Low JM, Do MHT, Lawson MA. Insulin augments gonadotropin-releasing hormone induction of translation in LbetaT2 cells. Mol Cell Endocrinol 2009; 311:47-54. [PMID: 19632296 PMCID: PMC2739255 DOI: 10.1016/j.mce.2009.07.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Revised: 06/23/2009] [Accepted: 07/06/2009] [Indexed: 10/20/2022]
Abstract
The integrated signaling of insulin and gonadotropin-releasing hormone in the pituitary gonadotropes may have a profound bearing on reproductive function, although the cross-receptor signaling mechanisms are unclear. We demonstrate that the insulin receptor is constitutively localized to non-caveolar lipid raft microdomains in the pituitary gonadotrope cell line LbetaT2. The localization to rafts is consistent with similar localization of the GnRH receptor. Insulin receptor phosphorylation occurs in raft domains and activates the downstream signaling targets Insulin Receptor Substrate1 and Akt/Protein Kinase B. Although insulin alone does not strongly activate the extracellular signal-regulated kinase second messenger cascade, co-stimulation potentiates the phosphorylation of the extracellular signal-regulated kinase by gonadotropin-releasing hormone. The co-stimulatory effect of insulin and gonadotropin-releasing hormone is also evident in increased activation of cap-dependent translation. In contrast, co-stimulation attenuates Akt/Protein Kinase B activation. Our results show that both gonadotropin-releasing hormone and insulin are capable of mutually altering their respective regulatory signaling cascades. We suggest that this provides a mechanism to integrate neuropeptide and energy homeostatic signals to modulate reproductive function.
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Affiliation(s)
- Amy M. Navratil
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Hyunjin Song
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Jeniffer B. Hernandez
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Brian D. Cherrington
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Sharon J. Santos
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Janine M. Low
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92093
| | - Minh-Ha T. Do
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92093
| | - Mark A. Lawson
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, CA 92093
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14
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Quennell JH, Mulligan AC, Tups A, Liu X, Phipps SJ, Kemp CJ, Herbison AE, Grattan DR, Anderson GM. Leptin indirectly regulates gonadotropin-releasing hormone neuronal function. Endocrinology 2009; 150:2805-12. [PMID: 19179437 PMCID: PMC2732287 DOI: 10.1210/en.2008-1693] [Citation(s) in RCA: 260] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The adipose-derived hormone leptin communicates information about metabolic status to the hypothalamic GnRH neuronal system. It is unclear whether leptin can act directly on GnRH neurons. To examine this, we used three approaches. First, the presence of leptin-induced signal transducer and activator of transcription-3 activation was examined in GnRH neurons in male and female rats. Intracerebroventricular treatment with 4 mug leptin-induced robust signal transducer and activator of transcription-3 expression within the anteroventral periventricular nucleus but not in GnRH neurons. Second, fertility was assessed in male and female CRE-loxP transgenic mice with conditional leptin receptor (Lepr) deletion from either all forebrain neurons or GnRH neurons only. Forebrain neuron LEPR deletion prevented the onset of puberty resulting in infertility in males and females and blocked estradiol-induced LH surge. However, mice with GnRH neuron-selective Lepr deletion exhibited normal fertility apart from a slight puberty delay in males. Lastly, the highly sensitive technique of single-cell nested PCR was used to test for Lepr transcript presence in individual GnRH neurons, identified in situ using GnRH-green fluorescent protein transgenics. Whereas 75% of positive control (proopiomelanocortin) neurons contained Lepr mRNA, no (none of 18) GnRH neurons were Lepr mRNA positive. Collectively, these results show that leptin does not act directly on GnRH neurons in rats and mice. Leptin appears to regulate GnRH function via forebrain neurons that are afferent to GnRH because forebrain neuronal LEPR deletion caused infertility. The location and phenotype of these leptin-responsive neurons remains to be elucidated.
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Affiliation(s)
- Janette H Quennell
- Department of Anatomy and Structural Biology, Centre for Neuroendocrinology, University of Otago School of Medical Sciences, Dunedin, New Zealand
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15
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Uenoyama Y, Tsukamura H, Kinoshita M, Yamada S, Iwata K, Pheng V, Sajapitak S, Sakakibara M, Ohtaki T, Matsumoto H, Maeda KI. Oestrogen-dependent stimulation of luteinising hormone release by galanin-like peptide in female rats. J Neuroendocrinol 2008; 20:626-31. [PMID: 18363811 DOI: 10.1111/j.1365-2826.2008.01703.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Galanin-like peptide (GALP), a ligand for three types of galanin receptor, is reported to have a role in regulating luteinising hormone (LH) release in male rodents and primates, but its role in LH release in female rodents remains controversial. The present study was conducted to test whether GALP has a stimulatory role in regulating LH secretion in female rats. The effect of i.c.v. infusion of GALP (5 nmol) on pulsatile LH release was investigated in Wistar-Imamichi strain female rats, or lean and obese Zucker rats. In oestradiol-17beta (oestradiol)-primed ovariectomised (OVX) Wistar-Imamichi female rats, i.c.v. infusion of GALP caused a gradual increase in LH release for the first 1.5 h after the infusion followed by an increased LH pulse frequency during the next 1.5 h, resulting in a significant increase in the mean LH concentrations and baseline levels of LH pulses throughout the sampling period and in the frequency of LH pulses at the last half of the period compared to vehicle-treated controls. The stimulatory effect of GALP was oestrogen-dependent because the same GALP treatment did not affect LH release in OVX rats in the absence of oestradiol. In lean Zucker rats, LH pulses were found in oestradiol-primed OVX individuals and central GALP infusion increased mean LH concentrations in the last half of the period. By contrast, few LH pulses were found in oestradiol-primed OVX obese Zucker rats reportedly with lower hypothalamic GALP expression. Central GALP infusion caused an apparent but transient increase in LH release, resulting in the significant increase in all pulse parameters of LH pulses compared to vehicle-treated controls in the first half of the sampling period. These results suggest that hypothalamic GALP is likely involved in stimulating GnRH/LH release, and that the stimulatory effect of GALP on LH release is oestrogen-dependent in female rats.
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Affiliation(s)
- Y Uenoyama
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
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16
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BRÜSSOW KP, SCHNEIDER F, TUCHSCHERER A, EGERSZEGI I, RÁTKY J. Comparison of Luteinizing Hormone, Leptin and Progesterone Levels in the Systemic Circulation (Vena jugularis) and near the Ovarian Circulation (Vena cava caudalis) during the Oestrous Cycle in Mangalica and Landrace Gilts. J Reprod Dev 2008; 54:431-8. [DOI: 10.1262/jrd.20069] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
| | | | | | | | - Jozsef RÁTKY
- Research Institute for Animal Breeding and Nutrition
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17
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Toufexis DJ, Davis C, Hammond A, Davis M. Progesterone attenuates corticotropin-releasing factor-enhanced but not fear-potentiated startle via the activity of its neuroactive metabolite, allopregnanolone. J Neurosci 2005; 24:10280-7. [PMID: 15537900 PMCID: PMC6730196 DOI: 10.1523/jneurosci.1386-04.2004] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Intact female rats and ovariectomized (OVX) rats with different ovarian steroid replacement regimens were tested for changes in corticotropin-releasing factor (CRF)-enhanced startle (increased acoustic startle amplitude after intracerebroventricular infusion of 1 mug of CRF). OVX rats injected with estradiol (E) followed by progesterone (P) showed a blunted CRF-enhanced startle effect compared with OVX and E-injected rats. CRF-enhanced startle also was reduced significantly in lactating females (high endogenous P levels) compared with cycling rats (low to moderate P levels), as well as in non-E-primed rats when P was administered acutely (4 hr before testing) or chronically (7 d P replacement). The ability of P to attenuate CRF-enhanced startle was probably mediated by its metabolite allopregnanolone [tetrahydroprogesterone (THP)], because THP itself had a similar effect, and chronic administration of medroxyprogesterone, which is not metabolized to THP, did not blunt CRF-enhanced startle but instead slightly increased it. These data suggest that P blunts CRF-enhanced startle through a mechanism involving its neuroactive metabolite THP, although a role for the P receptor cannot be completely ruled out. Finally, neither chronic P replacement nor acute THP affected fear-potentiated startle, suggesting that P metabolites have an effect on the bed nucleus of the stria terminalis and anxiety rather than on the amygdala and stimulus-specific fear.
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Affiliation(s)
- Donna J Toufexis
- Department of Psychiatry and Behavioral Sciences and The Center for Behavioral Neuroscience, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
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18
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Abstract
This paper is the 26th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over a quarter-century of research. It summarizes papers published during 2003 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology, Doctoral Sub-Program, Queens College, City University of New York, 65-30 Kissena Blvd., Flushing, NY 11367, USA.
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19
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Navarro VM, Fernández-Fernández R, Castellano JM, Roa J, Mayen A, Barreiro ML, Gaytan F, Aguilar E, Pinilla L, Dieguez C, Tena-Sempere M. Advanced vaginal opening and precocious activation of the reproductive axis by KiSS-1 peptide, the endogenous ligand of GPR54. J Physiol 2004; 561:379-86. [PMID: 15486019 PMCID: PMC1665361 DOI: 10.1113/jphysiol.2004.072298] [Citation(s) in RCA: 323] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The awakening of the gonadotrophic axis at puberty is the end-point of a complex cascade of sex developmental events that leads to the attainment of reproductive capacity. Recently, loss-of-function mutations of the gene encoding GPR54, the putative receptor for the KiSS-1-derived peptide metastin, have been linked to hypogonadotrophic hypogonadism, both in rodents and humans. However, the actual role of the KiSS-1/GPR54 system in the timing of puberty onset remains unexplored. We report herein that chronic central administration of KiSS-1 peptide to immature female rats induced the precocious activation of the gonadotrophic axis, as estimated by advanced vaginal opening, elevated uterus weight, and increased serum levels of luteinizing hormone (LH) and oestrogen. The central effect of KiSS-1 upon LH release appeared to be mediated via the hypothalamic LH-releasing hormone. In contrast, despite the well-documented permissive role of body fat stores and the adipocyte-derived hormone leptin in puberty maturation, acute activation of the gonadotrophic axis by KiSS-1 was persistently observed in pubertal animals under food deprivation, after central immunoneutralization of leptin, and in a model of leptin resistance. Overall, the present results, together with our recent data on maximum expression of KiSS-1 and GPR54 genes in the hypothalamus at puberty, provide novel evidence for a role of the KiSS-1 system as a downstream element in the hypothalamic network triggering the onset of puberty.
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Affiliation(s)
- V M Navarro
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, 14004 Córdoba, Spain
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