| 1. |
- Diaz-Cabiale, Z., et al.
(author)
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Long-term modulation by postnatal oxytocin of the α2-adrenoceptor agonist binding sites in central autonomic regions and the role of prenatal stress
- 2004
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In: Journal of neuroendocrinology (Print). - : Wiley. - 0953-8194 .- 1365-2826. ; 16:3, s. 183-190
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Journal article (peer-reviewed)abstract
- The aim of this work was to evaluate whether oxytocin administered in male rats subcutaneously early in life in the absence or presence of food restriction during pregnancy has life-long effects on the α2-agonist binding sites in the nucleus of the solitarii tract (NTS), in the hypothalamus and the amygdala, as evaluated by quantitative receptor autoradiography. Maternal food restriction alone increased the affinity of the α2-agonist [3H]UK14.304 binding sites exclusively in the NTS. In offspring from ad libitum fed dams, oxytocin treatment significantly increased the density of α2-agonist binding sites in the NTS and in the hypothalamus. The Kd value of the α2-agonist binding sites in the hypothalamus of these rats, but not in the other regions studied, was also significantly increased. In offspring from food-restricted dams, oxytocin treatment produced a significant increase of the Bmax values in the hypothalamus and the amygdala and the Kd value of the α2-agonist binding sites in the NTS of these rats also was selectively and significantly increased. These results suggest that a postnatal, oxytocin-induced increase of regional α2-adrenoceptor function can be seen in adulthood by a persistent, regionally selective increase in the density of central α2-adrenoceptor agonist binding sites, in the absence of an affinity change in the NTS. Such a regional increase of α2-adrenoceptor signalling in adulthood may contribute to the anti-stress action of postnatal oxytocin. By contrast, after prenatal stress, the potential increase in α2-adrenoceptor signalling takes place via selective increases of density with no changes of affinity of the α2-agonist binding sites in the hypothalamus and the amygdala.
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| 2. |
- Löf, Marie, 1971-, et al.
(author)
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Changes in basal metabolic rate during pregnancy in relation to changes in body weight and composition, cardiac output, insulin-like growth factor I, and thyroid hormones and in relation to fetal growth
- 2005
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In: American Journal of Clinical Nutrition. - 0002-9165 .- 1938-3207. ; 81:3, s. 678-685
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Journal article (peer-reviewed)abstract
- Background: The total energy cost of pregnancy is largely due to an elevated basal metabolic rate (BMR). Large variations in the BMR response to pregnancy have been reported, but the factors associated with this variability are incompletely known.Objective: The objective was to identify factors associated with variability in the BMR response to pregnancy.Design: In 22 healthy women, BMR, body weight (BW), total body fat (TBF), fat-free mass (FFM), circulatory variables, serum concentrations of insulin-like growth factor I (IGF-I), and thyroid hormones were measured before pregnancy and in gestational weeks 14 and 32. BMR and BW were also measured in gestational weeks 8, 20, and 35. Fetal weight was estimated in gestational week 31.Results: In gestational week 14, the increase in BMR correlated significantly with the corresponding increase in BW and with the prepregnancy percentage of TBF. Together these variables explained ≈40% of the variability in the BMR response. In gestational week 32, the increase in BMR correlated significantly with the corresponding changes in BW, TBF, FFM, IGF-I, cardiac output, and free triiodothyronine. The increase in BW in combination with fetal weight or with the elevated concentration of IGF-I in serum explained ≈60% of the variability in the increase in BMR.Conclusions: Weight gain and the prepregnancy percentage of TBF—ie, factors related to the maternal nutritional situation—are important factors with regard to the variability in the BMR response to pregnancy. Thus, it is important to consider the nutritional situation before and during gestation when assessing pregnancy energy requirements.
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| 3. |
- Olausson, Hanna, 1975-, et al.
(author)
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Effects of food restriction and pregnancy on the expression of insulin-like growth factors-I and -II in tissues from guinea pigs
- 2003
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In: Journal of Endocrinology. - : Bioscientifica. - 0022-0795 .- 1479-6805. ; 179:3, s. 437-445
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Journal article (peer-reviewed)abstract
- The insulin-like growth factor (IGF) system is subjected to pregnancy-associated changes in the circulation and is suggested to be of importance for partitioning of nutrients between the mother and the foetus. Interestingly, maternal undernutrition alters the pregnancy-associated changes, with possible adverse consequences for the mother and the foetus. However, it is not known how malnutrition and pregnancy alter the expression of mRNA for IGFs locally in different tIssues. The aims of this study were to investigate where IGF-I and IGF-II are expressed in guinea pigs and how this expression is altered during food restriction and pregnancy. Ad libitum-fed and food-restricted (fed 70% of the ad libitum-fed intake four weeks before pregnancy and throughout the study) guinea pigs were mated. On day 40 of pregnancy and on the corresponding day for virginal females the animals were killed. mRNA for IGF-I and IGF-II was analysed in various organs/tIssues by solution hybridisation. mRNA for IGF-I was expressed in high amounts in uterus, liver and adipose tIssues. The expression was not affected by food restriction, but was increased in liver and adipose tIssue and decreased in uterus by pregnancy. mRNA for IGF-II was expressed in high amounts in the placenta and liver. In the placenta the expression was decreased by food restriction. Pregnancy increased the levels of mRNA for IGF-II in the liver. Food-restricted dams had smaller foetuses and placentas. In conclusion, this study indicates an important role for the adipose tIssue during gestation, not only as an energy store but also as an endocrine tIssue expressing IGF-I. The decreased expression of IGF-II in the placenta due to food restriction is suggested to have adverse effects on placental structure and function.
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| 4. |
- Olausson, Hanna, 1975-, et al.
(author)
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Longitudinal study of the maternal insulin-like growth factor system before, during and after pregnancy in relation to fetal and infant weight
- 2008
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In: Hormone Research. - : S. Karger AG. - 0301-0163 .- 1423-0046. ; 69:2, s. 99-106
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Journal article (peer-reviewed)abstract
- Background: The maternal insulin-like growth factor (IGF) system is considered to be involved in fetal growth regulation. However, available data linking this system to fetal growth are contradictory and incomplete.Aims: To measure components of the IGF system before, during and after pregnancy in healthy women and to relate these results, and their changes during pregnancy, to fetal weight (gestational week 31) and birth weight.Methods: Serum concentrations of IGF-I, IGF-II, IGF-binding protein (IGFBP)-1, IGFBP-3 and IGFBP-3 protease activity were assessed in 23 women before conception, at weeks 8, 14, 20, 32 and 35 of pregnancy and 2 weeks postpartum. The data were analyzed using simple and multiple linear regression.Results: One third of the variability in fetal weight was explained by IGF-I in combination with IGFBP-3 protease activity, both assessed at gestational week 32 (p = 0.013). Birth weight was negatively correlated (r = –0.43 to –0.59) with IGFBP-1 at gestational week 20 (p = 0.041), 32 (p = 0.012) and 35 (p = 0.003).Conclusion: We propose there is a finely tuned balance among the components of the IGF system, providing a means for fetal growth regulation.
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| 5. |
- Sohlström, Annica, 1959-, et al.
(author)
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Oxytocin treatment during early life influences reproductive performance in ad libitum fed and food-restricted female rats
- 2002
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In: Biology of the Neonate. - : S. Karger AG. - 0006-3126 .- 1421-9727. ; 81:2, s. 132-138
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Journal article (peer-reviewed)abstract
- Oxytocin treatment may permanently alter endocrine axes resulting in anti-stress and anabolic effects. However, the nutritional status influences the effects of oxytocin. The specific aims of this study were to investigate the effects of postnatal oxytocin treatment on reproductive performance in adult life, by studying maternal weight gain, adiposity, plasma levels of IGF-I as well as fetal and placental weights in the following groups of animals: (1) Ad libitum fed dams coming from ad libitum fed mothers. (2) Ad libitum fed dams coming from food-restricted mothers. (3) Food-restricted dams coming from ad libitum fed mothers. (4) Food-restricted dams coming from food-restricted mothers. Oxytocin treatment postnatally had long-term effects and increased adiposity in pregnant dams and stimulated placental and fetal growth relative to saline-treated dams. However, if the dams themselves had been exposed to food restriction during fetal life, the effect of postnatal oxytocin treatment changed. The oxytocin-treated mothers were still fatter but had smaller fetuses. In conclusion, postnatal oxytocin treatment influences reproductive performance in later life but is dependent on the mother’s previous and current nutritional experience.
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