The early life environment has long-term implications for the risk of developing cardiovascular (CV) disease in adulthood. Fetal responses to changes in maternal nutrition may be of immediate benefit to the fetus, but the long-term effects of these adaptations may prove detrimental if nutrition in postnatal life does not match that predicted by the fetus on the basis of its prenatal environment. We tested this predictive adaptive response hypothesis with respect to CV function in sheep. We observed that a mismatch between pre-and postnatal nutrient environments induced an altered CV function in adult male sheep that was not seen when environments were similar. Sheep that received postnatal undernutrition alone had altered growth, CV function, and basal hypothalamo-pituitary-adrenal axis activity in adulthood. Prenatal undernutrition induced greater weight gain by weaning compared with the prenatal control diet, which may provide a reserve in the face of a predicted poor diet in later life. In an adequate postnatal nutrient environment (i.e., relatively mismatched), these offspring exhibited cardiac hypertrophy and altered CV function in adulthood. These data support the concept that adult CV function can be determined by developmental responses to intrauterine nutrition made in expectation of the postnatal nutritional environment, and that if these predictions are not met, the adult may be maladapted and at greater risk of CV disease. Our findings have substantial implications for devising strategies to reduce the impact of a mismatch in nutrition levels in humans undergoing rapid socio-economic transitions in both developing and developed societies.fetal development ͉ postnatal development ͉ predictive adaptive response
This book focuses on the role of education in relation to music and gender. Invoking a concept of musical patriarchy and a theory of the social construction musical meanings, Lucy Green shows how women's musical practices and gendered musical meanings have been reproduced, hand in hand, through history. Covering a wide range of music, including classical, jazz and popular styles, Dr Green uses ethnographic methods to convey the everyday interactions and experiences of girls, boys, and their teachers. She views the contemporary school music classroom as a microcosm of the wider society, and reveals the participation of music education in the continued production and reproduction of gendered musical practices and meanings.
Poor prenatal nutrition is associated with a greater risk of adult glucose intolerance and insulin insensitivity in the offspring. Skeletal muscle is the primary tissue for glucose utilization, and insulin resistance in muscle is the earliest identifiable abnormality in the pre-diabetic patient. We investigated the effect of early and late gestation undernutrition on structure and markers of growth and glucose metabolism regulation in the fetal triceps brachii (TB, slow-and fast-twitch myofibres) and soleus (slow-twitch myofibres) muscles. Pregnant sheep were fed 100% nutrient requirements (C, n = 8) or a restricted diet peri-implantation (PI, n = 9; 40%, 1-31 days gestation (dGA) (term ∼147)) or in late gestation (L, n = 6; 50%, 104-127 dGA). At 127 ± 1 dGA we measured myofibre and capillary density in the fetal TB and soleus muscles, and mRNA levels in the TB of insulin receptor (InsR), glucose transporter-4 (GLUT-4) and type 1 insulin-like growth factor receptor (IGF-1R). Total myofibre and capillary densities were lower in the TB, but not the soleus, of PI and L fetuses. The predominant effect in the L group was on slow-twitch myofibres. In TB, InsR, GLUT-4 and IGF-1R mRNA levels were greater in L group fetuses. Our finding of reduced myofibre density is consistent with a redistribution of resources at the expense of specific peripheral tissues by early and late gestation undernutrition which may be mediated by a decrease in capillary density. The increase in key regulatory components of glucose uptake following late gestation undernutrition may constitute a short-term compensation to maintain glucose homeostasis in the face of fewer type I (insulin-sensitive) myofibres. However, together these adaptations may influence the risk of later metabolic disease and thus our findings have implications for future strategies aimed at improving maternal diet.
1. In fetal sheep (123-129 days gestation) we investigated the effect of acute isocapnic hypoxia (Pa02) 12 + 0-6 mmHg) on the fetal heart rate (FHR), mean systemic arterial blood pressure (MAP), carotid blood flow (CBF), femoral blood flow (FBF), carotid vascular resistance (CVR) and femoral vascular resistance (FVR) with the infusion of either the nitric oxide synthase (NOS) inhibitor NG-nitro-L-arginine methyl ester (L-NAME) or saline vehicle.2. During normoxia, CBF was lower (P < 0 05) and MAP, FVR and CVR were higher with L-NAME than with vehicle infusion (P < 0 01, P < 0 05 and P < 0 01, respectively). FHR fell 15 min after the onset of L-NAME infusion (P < 0 05). During hypoxia in both groups, FHR showed an initial rapid fall (P < 0 05) and subsequent return to prehypoxic levels, and there was a fall in FBF (P < 0-01). MAP increased during hypoxia with vehicle (P < 0 05) but not L-NAME infusion: thus MAP was similar during hypoxia in the two groups. The rebound tachycardia seen during recovery in the vehicle group (P < 0-01) was not evident in the L-NAME group. The rise in CBF and fall in CVR during hypoxia with vehicle (P < 0.01 and P < 0 05, respectively) was absent with L-NAME infusion. FVR rose during hypoxia in both groups (P < 0 05). 3. Thus NOS inhibition alters basal systemic vascular tone in the late gestation fetus. The rise in CBF and fall in CVR during hypoxia is absent with NOS inhibition.
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