The hypothesized association between disturbance of the in utero environment and disease in later life is based largely on retrospective epidemiological studies which have focused upon the long-term consequences of in utero malnutrition [1]. Some population-based studies also point to prolonged effects of maternal diabetes on the fetus, including an increase in the frequency of gestational diabetes and of insulin resistance in adult offspring [2,3]. Prospective investigation of potential associations between a diabetic intrauterine milieu and disease in later life has been facilitated by animal models of chemically induced diabetes. These provide a means to evaluate responses to the intrauterine environment per se without the influence of hereditary traits [4±9]. Hyperglycaemia during rat gestation causes perturbations of glucose homeostasis in the offspring [4±9]; adult offspring of rats rendered diabetic with streptozotocin exhibit high plasma insulin concentrations during a glucose tolerance test [5], increased renal clearance of insulin [10] and are strongly resistant to the action of insulin as shown by the eugly- Diabetologia (1999) Summary Severe diabetes in pregnant rats produces persistent metabolic consequences in adult offspring. This study investigated whether diabetes in pregnant rats could also lead to cardiovascular abnormalities in the adult offspring. Blood pressure, heart rate and in vitro vascular reactivity of small arteries were evaluated in female adult offspring of control rats and of rats rendered diabetic with streptozotocin. Rise in blood pressures were similar in both groups of offspring but heart rate was lower in the diabetic offspring (p < 0.05). The rise in blood pressure associated with infusion of a nitric oxide synthase inhibitor was similar in both groups, but the associated decrease in heart rate was more pronounced in diabetic offspring (p < 0.01). Small mesenteric arteries from this group showed enhanced sensitivity to noradrenaline (p < 0.05) and abnormal endothelium-dependent relaxation to acetylcholine (p < 0.01) and bradykinin (p < 0.05). Reduction in acetylcholine induced relaxation, reflected reduced synthesis of nitric oxide or a cyclooxygenase product and was not attributable to an endothelium-derived hyperpolarizing factor. Sensitivity to exogenous nitric oxide was normal. A subgroup of pups born to diabetic dams were suckled by control maternal dams and a subgroup of those born to controls by diabetic dams. Suckling was an important determinant of impaired growth; offspring of diabetic rats suckled by their own mother and those of control rats by diabetic dams showed impaired growth rates whereas growth of offspring of diabetic rats suckled by control dams paralleled those of control rats suckled by their own mother. [Diabetologia (1999)
Food restriction during pregnancy in rats induces intrauterine growth retardation with consequences persisting into adulthood. In the present study we have investigated the hypothesis that malnutrition in pregnant rats may lead to altered cardiovascular function in adult female offspring. Perinatal growth retardation was induced by a 50 % reduction of normal dietary intake in rats during the second half of pregnancy. Systolic and diastolic blood pressure values and heart rate were recorded in conscious female offspring (100 d old) using a femoral artery probe. No significant differences in heart rate, or in systolic and diastolic blood pressures were recorded between control offspring and offspring of nutritionally deprived rats. In order to ascertain whether cardiovascular variables in the offspring were influenced by lactation, subgroups of offspring from food-restricted dams were fostered with lactating dams fed on a normal diet. Blood pressure and heart rate were also found to be normal in these offspring. The rise in blood pressure associated with NO inhibition was similar in all groups. Isolated resistance artery function was assessed in vitro in offspring (100-120 d old) of a second group of semistarved dams. Small mesenteric arteries from these animals showed reduced endotheliumdependent relaxation (to acetylcholine and bradykinin), but enhanced sensitivity to exogenous NO (sodium nitroprusside). We conclude that food restriction during the second half of pregnancy and/or lactation does not induce hypertension in adult offspring, but may effect subtle changes in vascular function.
Gene expression profiling in animal models exposed to cigarette mainstream smoke (CS) shapes up as a promising tool for investigating the molecular mechanisms involved in the onset and development of CS-related disease and may aid in the identification of disease candidate genes. Here we report on differential gene expression in lungs of rats exposed for 2, 7, and 13 weeks to 300 and 600 microg total particulate matter/l CS with sacrifice 2, 6, or 20 h after the last exposure. Regarding antioxidant and xenobiotic-metabolizing (phase I/II) enzymes, a stereotypic, mostly transient, expression pattern of differentially expressed genes was observed after each exposure period. The expression patterns were generally dose dependent for antioxidant and phase II genes and not dose dependent for phase I genes at the CS concentrations tested. However, with increasing length of exposure, there was a distinct, mostly sustained and dose-sensitive, expression of genes implicated in innate and adaptive immune responses, clearly pointing to an emerging inflammatory response. Notably, this inflammatory response included the expression of lung disease-related genes not yet linked to CS exposure, such as galectin-3, arginase 1, and chitinase, as well as genes encoding proteolytic enzymes. Finally, our experiments also revealed a CS exposure-dependent shift in the cyclical expression of genes involved in controlling the circadian rhythm. Altogether, these results provide further insight into the molecular mechanisms of CS-dependent disease onset and development and thus may also be useful for defining CS-specific molecular biomarkers of disease.
Previous work in humans and rats has revealed a link between perinatal growth retardation and glucose intolerance in adulthood. Both maternal semistarvation and severe diabetes are accompanied by perinatal growth retardation in rats. In this study, we compared the effect of these conditions on tissue glucose uptake in their female offspring. Glucose uptake was measured as glucose metabolic index (GMI), using 2-deoxy-[1-3H]-glucose, in the postabsorptive state and during euglycemic hyperinsulinemia. The GMI was measured in insulin-sensitive tissues (5 skeletal muscles, diaphragm and white adipose tissue) and in two noninsulin-sensitive tissues (duodenum and brain) of adult offspring of normal dams, dams rendered diabetic with streptozotocin on d 11 of pregnancy, and dams fed half normal rations from d 11 of pregnancy. Whole-body insulin resistance, measured by decreased glucose infusion rate during hyperinsulinemia, was milder in offspring of semistarved rats (O-SR) than in offspring of diabetic rats (O-DR). The basal GMI did not differ among the three groups in any tissue except tibialis anterior; during hyperinsulinemia, GMI was significantly greater in the insulin-sensitive tissues of all three groups. GMI of skeletal muscles and adipose tissue during hyperinsulinemia did not differ between control rats and O-SR; in contrast, the GMI was 25-50% lower in skeletal muscles of O-DR during hyperinsulinemia than in those of control rats or O-SR. Thus, maternal semistarvation and diabetes have dissimilar effects on peripheral insulin sensitivity of the adult female offspring. Because both conditions are associated with perinatal growth retardation and fetal hypoinsulinemia, other mechanisms must be identified to explain impaired glucose uptake by skeletal muscles in the offspring of diabetic rats.
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