Roles and Regulation of Leptin in Reproduction

Henson, Michael C.; Castracane, V. Daniel

doi:10.1007/978-0-387-31416-7_9

Cited by 4 publications

(5 citation statements)

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“…This slow increase suggests that variation in placental leptin production does exist within a single species. AL bats may not experience hyperleptinemia with the associated leptin resistance during pregnancy (Enriori et al 2006;Henson and Castracane 2006). It is also possible that this resuh reflects in part the constraints of using a qualitative assessment of pregnancy stage in this study (although our assessment method was consistently used on all bats fi-om all colonies).…”

Section: Discussionmentioning

confidence: 84%

“…Leptin is also associated with reproduction, v/ith levels of plasma ieptin increasing during pregnancy in all mammals, including bats, that have been studied to date (Henson and Castracane 2000;Kronfeld-Schor et al 2001;Zhao et al 2003}. The increase in levels of plasma leptin during pregnancy is unrelated to adiposity.…”

Section: Introductionmentioning

confidence: 95%

“…2001). Leptin resistance during pregnancy allows levels of maternal serum leptin to rise (Henson and Castracane 2006) while maintaining energy consumption to match increasing maternal metabolic demands (Kunz and Orrell 2004).…”

Section: Introductionmentioning

confidence: 99%

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Macro‐ and Microgeographic Variation in Metabolism and Hormone Correlates in Big Brown Bats (Eptesicus fuscus)

Richardson¹,

Heeren²,

Widmaier³

et al. 2009

Physiological and Biochemical Zoology

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To better understand intraspecific variation in basal metabolic rate (BMR), we examined environmental, physiological, and/or cellular bases for residual variation in BMR in big brown bats, Eptesicus fuscus. We measured BMR and plasma levels of thyroid hormone (T(3)) and leptin in bats captured in maternity colonies in eastern Massachusetts (MA; northern population) and in Alabama and Georgia (ALGA; southern population) to assess macrogeographic (between- or among-population) and microgeographic (within-population) variation in those traits. After accounting for effects of body mass, stage of pregnancy, and within-population variation, bats from the northern population did not differ significantly in BMR, T(3), or leptin values from those in the southern population. However, after accounting for the effects of body mass and stage of pregnancy, a test for differences in all traits among colonies from both populations was significant. For BMR, bats differed significantly among the northern colonies. Moreover, after removing the effects of body mass and stage of pregnancy, bats from the AL colony had significantly higher BMR than did bats from all other colonies except one in MA, and they had significantly higher T(3) levels but lower leptin levels than did bats from two other colonies. The presence of among-colony and within-population variation for these traits suggests that proximate (nonevolutionary) factors (e.g., microhabitat differences such as roost type) play an important role in shaping intraspecific variation in BMR and its hormone correlates.

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Section: Discussionmentioning

confidence: 84%

Section: Introductionmentioning

confidence: 95%

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Macro‐ and Microgeographic Variation in Metabolism and Hormone Correlates in Big Brown Bats (Eptesicus fuscus)

Richardson¹,

Heeren²,

Widmaier³

et al. 2009

Physiological and Biochemical Zoology

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“…In humans and animals, leptin has been reported to have an effect on restriction of food intake and to increase energy expenditure. Subsequently, leptin has been implicated to reduce the production and secretion of insulin by affecting pancreatic β cell function (Henson and Castracane, 2006). Leptin has also been identified as an important indicator of adipose mass and nutritional status in many species (Buff et al, 2002).…”

Section: The Role Of Leptin and Adiponectinementioning

confidence: 99%

“…It appears that leptin affects the successful rate of fertilization, placental development, the regulation of puberty and maintenance of pregnancy (Ceddia et al, 2002, Henson andCastracane, 2006). More importantly, placental leptin contributes to the increase in maternal circulating leptin during late pregnancy to regulate the energy metabolism balance.…”

Section: Leptin and Body Conditionmentioning

confidence: 99%

Insulin resistance in pregnant mares: the influence of body condition

Song¹

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Pregnancy is characterized by slight insulin resistance (IR), impaired glucose clearance and compensatory increased insulin secretion. More severe IR may, however, result in pancreatic β cell failure during pregnancy, and in turn leads to prolonged insulin insensitivity after birth, and/or an increased risk of diabetes in later life. This condition is known as gestational diabetes mellitus (GDM) in pregnant women those, in particular, who suffer from obesity. Although IR has been considered as a factor to increase the risk of laminitis and osteochondritis dissecans (OCD) in horses, there is no reported direct evidence showing that GDM occurs in pregnant mares. Hence, the present research aimed to study the occurrence of IR in pregnant mares with different body condition score (BCS) and potential long-term effects in the subsequent pregnancy.Experiment 1: In the first year, 13 pregnant mares were allocated into either a high body condition group (HBCS, n=6) or low body condition group (LBCS, n=7) based on BCS assessed at mid gestation on a scale of 1 to 9. The two groups were fed separately with either a high energy diet (150 % DE requirements) or a moderate energy diet (100 % DE requirements) to attain a BCS of HBCS ≥ 6 and LBCS ≤ 4, respectively, during the last trimester of pregnancy. Weekly blood samples were taken from week 41 to 46 of pregnancy to confirm the differences between the groups by determining the basal leptin concentrations. Frequently sampled intravenous glucose tolerance tests (FSIGTT) were performed at day 290 and 320 of gestation while insulin and glucose responses were analyzed by minimal model analyses to determine insulin sensitivity (Si), glucose effectiveness (Sg), acute insulin response to glucose (AIRg) and disposition index (DI).Experiment 2: In the subsequent year, lactating mares from the previous experiment were mated again prior to examinations for ongoing dysfunction of pancreatic β cell. Four mares from each of the previous HBCS and LBCS groups were selected for the study. During pregnancy animals were individually fed to ensure similarity in BCS between the groups and BCS were evaluated frequently.An oral glucose tolerance test (OGTT) was carried out at day 325 of gestation to study the insulin and glucose responses in late pregnancy.ii It was found in Experiment 1 that the BCS in the HBCS group was significantly (P<0.001) higher than those in the LBCS group at day 290 (6.3±0.4 vs. 4.1±0.3) and day 320 (7.2±0.5 vs. 3.3±0.3) of gestation. It was noted that BCS in the HBCS group was significantly (P<0.05) increased, whilst those in LBCS group significantly (P<0.01) decreased over the period. Live weight was, however, similar (p>0.05) between the groups during the period. In addition, Plasma leptin was significantly higher (P<0.05) in the HBCS group as compared to those in the LBCS group from week 41 to 46 of gestation. There was no significant difference found (p>0.05) in basal insulin or glucose levels between the groups at either day 290 or day 320 of gestation. No sig...

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Metals in human placenta: focus on the effects of cadmium on steroid hormones and leptin

Stasenko

Bradford

Piasek

et al. 2009

J of Applied Toxicology

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106

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Cadmium and other metallic ions can act as metalloestrogens and endocrine disruptors of reproductive tissues and fetal development in mammals, including humans. The detrimental effects occur with respect to the synthesis of both steroid and polypeptide hormones in the placenta. Leptin is produced by the trophoblast and may regulate fetal organogenesis and development. In human term placentas, concentrations of toxic metals and their effects on steroidogenesis were assessed in healthy parturients (109 non-smokers and 99 smokers) in relation to tobacco smoking. Trace elements (cadmium, lead, iron, zinc and copper) were analyzed in placentas using atomic absorption spectroscopy, and steroid hormones (progesterone and estradiol) were assayed in placental samples by an enzyme-immunometric method. Cadmium concentrations were doubled in placentas of smokers as compared with non-smokers, and placental lead and zinc concentrations increased significantly. Placental concentrations of iron, copper, progesterone and estradiol did not differ. In addition, human trophoblast cells were co-cultured with 0, 5, 10 or 20 microm CdCl(2) for 96 h and leptin mRNA assessed by quantitative polymerase chain reaction. Leptin mRNA declined dose-responsively as a result of CdCl(2) exposure. Collectively, the results confirm that human placental tissue offers a unique opportunity to biomonitor cadmium exposure in both the maternal and the internal fetal environments. In addition, the results strongly suggest that cadmium may cause a decline in placental leptin synthesis, as we have previously shown for placental progesterone production. This may constitute further evidence of the endocrine-disrupting effects of cadmium, as a constituent of tobacco smoke, on reproduction in women.

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Roles and Regulation of Leptin in Reproduction

Cited by 4 publications

References 230 publications

Macro‐ and Microgeographic Variation in Metabolism and Hormone Correlates in Big Brown Bats (Eptesicus fuscus)

Macro‐ and Microgeographic Variation in Metabolism and Hormone Correlates in Big Brown Bats (Eptesicus fuscus)

Insulin resistance in pregnant mares: the influence of body condition

Metals in human placenta: focus on the effects of cadmium on steroid hormones and leptin

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