| 1. |
- Alexanderson, Camilla, 1978, et al.
(författare)
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Early postnatal oestradiol exposure causes insulin resistance and signs of inflammation in circulation and skeletal muscle.
- 2009
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Ingår i: The Journal of endocrinology. - 1479-6805. ; 201:1, s. 49-58
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Tidskriftsartikel (refereegranskat)abstract
- Early postnatal events can predispose to metabolic and endocrine disease in adulthood. In this study, we evaluated the programming effects of a single early postnatal oestradiol injection on insulin sensitivity in adult female rats. We also assessed the expression of genes involved in inflammation and glucose metabolism in skeletal muscle and adipose tissue and analysed circulating inflammation markers as possible mediators of insulin resistance. Neonatal oestradiol exposure reduced insulin sensitivity and increased plasma levels of monocyte chemoattractant protein-1 (MCP-1) and soluble intercellular adhesion molecule-1. In skeletal muscle, oestradiol increased the expression of genes encoding complement component 3 (C3), Mcp-1, retinol binding protein-4 (Rbp4) and transforming growth factor beta1 (Tgfbeta1). C3 and MCP-1 are both related to insulin resistance, and C3, MCP-1 and TGFbeta1 are also involved in inflammation. Expression of genes encoding glucose transporter-4 (Glut 4), carnitine-palmitoyl transferase 1b (Cpt1b), peroxisome proliferator-activated receptor delta (Ppard) and uncoupling protein 3 (Ucp3), which are connected to glucose uptake, lipid oxidation, and energy uncoupling, was down regulated. Expression of several inflammatory genes in skeletal muscle correlated negatively with whole-body insulin sensitivity. In s.c. inguinal adipose tissue, expression of Tgfbeta1, Ppard and C3 was decreased, while expression of Rbp4 and Cpt1b was increased. Inguinal adipose tissue weight was increased but adipocyte size was unaltered, suggesting an increased number of adipocytes. We suggest that early neonatal oestrogen exposure may reduce insulin sensitivity by inducing chronic, low-grade systemic and skeletal muscle inflammation and disturbances of glucose and lipid metabolism in skeletal muscle in adulthood.
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| 2. |
- Alexanderson, Camilla, 1978, et al.
(författare)
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Influence of having a male twin on body mass index and risk for dyslipidemia in middle-aged and old women.
- 2011
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 35, s. 1466-1469
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Tidskriftsartikel (refereegranskat)abstract
- Background:Animal experiments suggest that exposure to elevated levels of androgens during development by means of so-called hormonal programming causes metabolic aberrations at adulthood. An indirect strategy to address the possible importance of such an influence also in humans would be to study female dizygotic twins, presuming that those with a twin brother-due to diffusion of testosterone-have been exposed to higher androgen levels prenatally.Design:We have compared 8409 women with a male twin with 9166 women with a dizygotic female twin with respect to self-reported indices of anthropometry and metabolic aberrations at age 42 or older.Results:Body mass index (BMI), body weight and rate of dyslipidemia were moderately, but significantly, higher in women from opposite-sexed (OS) twin pairs; splitting for age revealed this difference to be present in those 60 years of age only.Conclusion:The results (i) support the notion that comparisons of women with a twin brother with women from same-sexed twin pairs may be used to shed light on possible long-term effects of interindividual variations in early androgen exposure, and (ii) suggest that the effects of early androgen exposure on metabolism previously observed in animal experiments are of relevance also for humans.International Journal of Obesity advance online publication, 8 March 2011; doi:10.1038/ijo.2011.18.
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| 3. |
- Alexanderson, Camilla, 1978, et al.
(författare)
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Postnatal testosterone exposure results in insulin resistance, enlarged mesenteric adipocytes, and an atherogenic lipid profile in adult female rats: comparisons with estradiol and dihydrotestosterone.
- 2007
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 148:11, s. 5369-76
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Tidskriftsartikel (refereegranskat)abstract
- Postnatal events contribute to features of the metabolic syndrome in adulthood. In this study, postnatally administered testosterone reduced insulin sensitivity and increased the mesenteric fat depot, the size of mesenteric adipocytes, serum levels of total cholesterol, low-density lipoprotein cholesterol, and triglycerides, and the atherogenic index in adult female rats. To assess the involvement of estrogen and androgen receptors in these programming effects, we compared testosterone-exposed rats to rats exposed to estradiol or dihydrotestosterone (DHT). Estradiol-treated rats had lower insulin sensitivity than testosterone-treated rats and, like those rats, had enlarged mesenteric adipocytes and increased triglyceride levels. DHT also reduced insulin sensitivity but did not mimic the other metabolic effects of testosterone. All treated rats were probably anovulatory, but only those treated with testosterone had reduced testosterone levels. This study confirms our previous finding that postnatal administration of testosterone reduces insulin sensitivity in adult female rats and shows that this effect is accompanied by unfavorable changes in mesenteric fat tissue and in serum lipid levels. The findings in the estradiol and DHT groups suggest that estrogen receptors exert stronger metabolic programming effects than androgen receptors. Thus, insults such as sex hormone exposure in early life may have long-lasting effects, thereby creating a predisposition to disturbances in insulin sensitivity, adipose tissue, and lipid profile in adulthood.
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| 4. |
- Dahlgren, Jovanna, 1964, et al.
(författare)
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Prenatal cytokine exposure results in obesity and gender-specific programming.
- 2001
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Ingår i: American journal of physiology. Endocrinology and metabolism. - 0193-1849. ; 281:2
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Tidskriftsartikel (refereegranskat)abstract
- Prenatal events appear to program hormonal homeostasis, contributing to the development of somatic disorders at an adult age. The aim of this study was to examine whether maternal exposure to cytokines or to dexamethasone (Dxm) would be followed by hormonal consequences in the offspring at adult age. Pregnant rats were injected on days 8, 10, and 12 of gestation with either human interleukin-6 (IL-6) or tumor necrosis factor-alpha (TNF-alpha) or with Dxm. Control dams were injected with vehicle. All exposed offspring developed increased body weight (P < 0.05--0.001), apparently due to an increase of 30--40% in adipose tissue weight (P < 0.05--0.01). Corticosterone response to stress was increased in the IL-6 group (P < 0.05-0.01). Dxm-treated male rats exhibited blunted Dexamethasone suppression test results. In male rats, insulin sensitivity was decreased after IL-6 exposure (P < 0.01), whereas basal insulin was elevated in the TNF-alpha group (P < 0.01). In female rats, plasma testosterone levels were higher in all exposed groups compared with controls (P < 0.01--0.001), with the exception of Dxm-exposed offspring. Males in the TNF-alpha group showed decreased locomotor activity (P < 0.05), and females in the IL-6 group showed increased locomotor activity (P < 0.05). These results indicate that prenatal exposure to cytokines or Dxm leads to increased fat depots in both genders. In females, cytokine exposure was followed by a state of hyperandrogenicity. The results suggest that prenatal exposure to cytokines or Dxm can induce gender-specific programming of neuroendocrine regulation with consequences in adult life.
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| 5. |
- Nilsson, Cecilia, et al.
(författare)
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Increased insulin sensitivity and decreased body weight in female rats after postnatal corticosterone exposure.
- 2002
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Ingår i: European journal of endocrinology / European Federation of Endocrine Societies. - 0804-4643. ; 146:6, s. 847-54
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Glucocorticoids are important for normal brain development. Elevation or removal of these hormones can permanently modify the structure and function of the fetal brain. The purpose of this study was to examine the effects of postnatal corticosterone exposure of female pups on metabolic, endocrine and anthropometric variables in adulthood. DESIGN: Female pups were given subcutaneous injections of corticosterone (5 mg/kg, CORT) or vehicle 3 and 5 days after birth. RESULTS: From 6 weeks of age, the CORT rats weighed significantly less than did controls, with diminished fat depots, decreased serum levels of leptin and reduced food intake. Adult CORT rats showed increased insulin sensitivity, measured by hyperinsulinemic, euglycemic clamp (5 mU/kg/min), as compared with controls. CORT rats had lower basal corticosterone levels and lower corticosterone levels 15 and 90 min after exposure to stress. CONCLUSION: The results indicate that postnatal exposure to corticosterone leads to increased insulin sensitivity, low body weight with diminished fat depots, leptin and food intake. This suggests that postnatal exposure to corticosterone induces specific programming, with consequences in adult life.
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| 6. |
- Nilsson, Cecilia, et al.
(författare)
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Maternal endotoxemia results in obesity and insulin resistance in adult male offspring.
- 2001
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Ingår i: Endocrinology. - 0013-7227. ; 142:6, s. 2622-30
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Tidskriftsartikel (refereegranskat)abstract
- Events in utero appear to be important factors contributing to the development of somatic disorders at adult age. The aim of this study was to examine whether maternal immune challenge would be followed at adult age by metabolic and endocrine abnormalities in the offspring. Pregnant rats were given injections of either endotoxin (Escherichia coli lipopolysaccharide; 0.79 mg/kg, ip) or vehicle on days 8, 10, and 12 of gestation. Adult male offspring to lipopolysaccharide-exposed dams were heavier than controls (P < 0.05) and showed increased adipose tissue weights (P < 0.05), elevated food intake (P < 0.05), and increased circulating leptin (P < 0.01). The effect of insulin on glucose uptake was reduced, as measured by an euglycemic hyperinsulinemic clamp technique (P < 0.05). Serum levels of 17beta-estradiol and progesterone were elevated (P < 0.01 and P < 0.05, respectively). Baseline levels of corticosterone were normal, but the corticosterone response to stress was attenuated (P < 0.05), and hippocampal glucocorticoid receptor protein was up-regulated (P < 0.05). Female offspring were uninfluenced, except for increased testosterone levels (P < 0.05), increased baseline corticosterone levels (P < 0.05), and enlargement of heart and adrenals (P < 0.05). The results indicate that maternal endotoxemia leads to obesity, insulin resistance, and high serum levels of leptin in the adult male offspring. This study reports a novel animal model of obesity with features of the metabolic syndrome.
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| 7. |
- Nilsson, Cecilia, et al.
(författare)
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Postnatal endotoxin exposure results in increased insulin sensitivity and altered activity of neuroendocrine axes in adult female rats.
- 2002
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Ingår i: European journal of endocrinology / European Federation of Endocrine Societies. - 0804-4643. ; 146:2, s. 251-60
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Severe postnatal infection leads to a systemic inflammatory response with release of cytokines and glucocorticoids, representing a stressful event for the newborn child. The purpose of this study was to mimic this situation and to study the effects of early postnatal endotoxin exposure of female rat pups on metabolic, endocrine and anthropometric variables in adulthood. DESIGN: Female pups were given subcutaneous injections of lipopolysaccharides (LPS; Salmonella enteriditis, 0.05 mg/kg) or vehicle 3 and 5 days after birth. RESULTS: Six hours after injection, LPS-treated rats had higher corticosterone levels than controls. As adults, LPS-exposed female rats showed increased insulin sensitivity (P<0.05), measured with the hyperinsulinemic euglycemic clamp (5 mU/kg per min). They exhibited a higher locomotor activity (P<0.05) and increased skeletal muscle mass in comparison with controls (P<0.05). Basal ACTH and corticosterone levels in LPS-treated rats were elevated (P<0.05), as were corticosterone levels after exposure to a novel environment stress (P<0.05). The adrenals were morphologically changed and enlarged (P<0.05) in LPS-exposed rats at 11 weeks of age, and a higher density of hypothalamic but not hippocampal glucocorticoid receptor protein was found in the LPS-treated rats (P<0.05). Furthermore, circulating progesterone levels were lower (P<0.05) and testosterone tended to be higher. CONCLUSION: The results indicate that postnatal exposure to LPS leads to increased insulin sensitivity in the adult female rat. In addition, LPS-treated rats showed changes in the regulation of hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axes. This study suggests that postnatal exposure to an endotoxin such as LPS can induce specific programming of neuroendocrine regulation, with long-term consequences in adult life.
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| 8. |
- Nilsson, Cecilia, et al.
(författare)
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Reductions in adipose tissue and skeletal growth in rat adult offspring after prenatal leptin exposure.
- 2003
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Ingår i: The Journal of endocrinology. - 0022-0795. ; 176:1, s. 13-21
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Tidskriftsartikel (refereegranskat)abstract
- Leptin is involved in regulating food intake, energy balance and bone formation. Increasing evidence suggests that leptin is also involved in fetal growth and development. The aim of this study was to determine if increased maternal leptin is followed by changes in body composition, skeletal growth or hormonal regulation in the adult rat offspring. Pregnant rats were given injections of either human recombinant leptin (3.5 mg/kg, i.p.) or vehicle on days 8, 10 and 12 of gestation. Both genders of leptin-exposed offspring showed significantly reduced adipose tIssue weight at adult age. Skeletal growth and cortical bone dimensions were significantly reduced. Circulating testosterone levels were significantly increased in female leptin-exposed offspring, and male leptin-exposed offspring had significant testicular enlargement. No significant effects were seen on circulating leptin levels or hypothalamic protein levels of the leptin receptor. The results demonstrate that maternally administered leptin is involved in fetal growth and development, leading to lean offspring with reduced skeletal growth.
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| 9. |
- Samuelsson, Anne-Maj, 1977, et al.
(författare)
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Prenatal exposure to interleukin-6 results in hypertension and increased hypothalamic-pituitary-adrenal axis activity in adult rats.
- 2004
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 145:11, s. 4897-911
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Tidskriftsartikel (refereegranskat)abstract
- During pregnancy, systemic inflammatory responses induce cytokines that may stress the fetus and contribute to cardiovascular and neuroendocrine dysfunction in adulthood. We evaluated the effects of early and late prenatal exposure to IL-6 on mean systolic arterial pressure (MSAP) and hypothalamic-pituitary-adrenal (HPA) axis regulation in male and female rats at 5-24 wk of age. MSAP and ACTH and corticosterone levels were measured basally and in response to a novel environment, immobilization stress, and stimulation with corticotropin-releasing factor (CRF) and ACTH. In addition, mRNA expression and protein levels of glucocorticoid receptor, mineralocorticoid receptor, CRF receptor type 1, and CRF were estimated in brain areas thought to mediate central effects of corticosteroids on the HPA axis and on central neuroendocrine regulation of MSAP. Both early and late prenatal IL-6 exposure led to hypertension, which was evident in females at 5 wk of age. In adult rats, basal ACTH and corticosterone levels were elevated, the responses to stress and stimulation tests were of extended duration, and circadian rhythm during the light period was flattened and reversed. Mineralocorticoid receptor and glucocorticoid receptor mRNA expression was reduced in the hippocampus, the CRF level was increased in the hypothalamus, and CRF receptor type 1 mRNA expression was increased in the pituitary. These findings suggest that fetal stress induced by prenatal exposure to IL-6 leads to hypertension and dysregulation of HPA axis activity during adulthood.
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