Thiamin status of the offspring of diabetic rats

Erythrocyte transketolase activity and thiamin pyrophosphate effect were examined in the offspring of streptozotocin-diabetic rats. Thiamin reserve was found to be significantly reduced in litters of untreated diabetic rats as compared to control and to insulin-treated diabetic rats. Supplementation of the untreated diabetic dams throughout pregnancy with oral thiamin was associated with a significantly improved thiamin status of the litters. We conclude that, due to enhanced fetal glucose turnover during diabetic gestation, a fetal thiamin deficiency state may evolve; this condition can be remedied with maternal thiamin supplementation.     

Plasma amino acids in diabetic pregnant rats and in their fetal and adult offspring

Amino acid profiles and total amino-acid concentrations are established in nonfasting plasma of pregnant control, mildly diabetic and severely diabetic rats, and of their fetal and adult offspring. In pregnant rats at day 20 of gestation plasma amino acids can be regarded as normal in mildly diabetic mothers, but are significantly decreased in severely diabetic mothers. In fetuses of control rats, amino acid levels are twice as high as in the mother (fetomaternal ratio 2.0); in the fetuses of mildly diabetic mothers they are significantly lower than normal (fetomaternal ratio 1.3); in the fetuses of severely diabetic mothers they are also significantly lower than normal but with a normal fetomaternal ratio (fetomaternal ratio 2.0). In adult offspring of mildly diabetic mothers the concentration of almost all amino acids as well as that of total amino acid pool is significantly lower than in the controls; in the offspring of severely diabetic mothers they can be regarded as normal. No specific amino acid or group of amino acids can be held responsible for any of these changes, since all differences with control values display an overall effect, involving all or almost all amino acids.     

Evaluation of insulin sensitivity in obese offspring of diabetic rats by hyperinsulinemic-euglycemic clamp technique

Young adult macrosomic offspring of streptozotocin-induced mildly hyperglycemic rats exhibit accelerated growth through the first 10 wk of age. At 10 wk, oral glucose loading resulted in elevated plasma insulin and glucose concentrations compared to controls. To assess the mechanism of the abnormal glucose tolerance in vivo, hyperinsulinemic-euglycemic clamp studies were performed. Ten-wk-old rats were fasted overnight, and porcine insulin was infused (2.4 mU.kg-1.min-1). Glucose was infused concurrently at varying rates to maintain euglycemia for 40-60 min. Insulin levels were raised from a baseline value of 163 +/- 57 pmol/L (23 +/- 8 microU/mL) (SD) to 476 +/- 57 pmol/L (67 +/- 8 microU/mL) at steady state for males and from 178 +/- 43 pmol/L (25 +/- 6 microU/mL) to 454 +/- 43 pmol/L (64 +/- 6 microU/mL) for females. The results showed that the macrosomic male and female animals were significantly less sensitive to the effects of insulin than were their respective controls; this was evident by a lower increment in glucose disposal rate per unit increase in insulin (0.04 +/- 0.01 versus 0.11 +/- 0.03 for males and 0.05 +/- 0.03 versus 0.18 +/- 0.07 mg.kg-1 per microU/mL for females). The endogenous glucose production by the liver in the basal (fasted) state in the macrosomic group compared to controls was higher, suggesting possible hepatic insulin resistance. However, endogenous glucose production was suppressed to the same degree between the experimental and control groups during the hyperinsulinemic period, suggesting that the hepatic insulin resistance can be overcome by high insulin levels.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intellectual development of offspring of diabetic mothers

We prospectively evaluated the intellectual development of 33 children who were born to 33 diabetic Japanese mothers and compared them to 34 children born to non-diabetic mothers (controls) during the same period at Kurume University Hospital between 1987 and 1989. Birthweight, maternal age and the infant's age at the time of intelligence testing did not differ significantly between the offspring of diabetic mothers (ODMs) and controls. Tanaka-Binet intelligence scores were significantly lower in the ODMs at 3 years of age than in controls (98.4 ± 17.4 versus 113.4 ± 15.3) (p = 0.0005). No correlation was found between IQ and maternal haemoglobin A_1c levels during pregnancy. Maternal age and infant IQ were inversely correlated in ODMs (p = 0.0298, r = ?0.3984), but no such correlation was demonstrated in the controls. The results indicated that the ODMs may show a poorer intellectual development than those of non-diabetic mothers.     

Congenital malformations in offspring of diabetic rats: experimental study on the influence of the diet composition and magnesium intake

In spite of improvements in the treatment of diabetes, the risk of congenital malformations in diabetic pregnancy is three to four times higher than in normal pregnancy. This might be due to the metabolic abnormalities of diabetic pregnancy that also affect mineral metabolism. Since diabetes can lower both maternal and fetal blood Mg levels, and Mg deficiency has been shown to be teratogenic in laboratory animals, we decided to investigate which effects Mg deficiency would have in inducing embryopathy in diabetic animals. Female CD rats were divided into six groups. Groups 1 and 2 were fed a standard diet (Mg content 4,200 ppm), groups 3-6 a purified diet (Mg contents 4,200, 500, 250, or 125 ppm). Groups 2-6 had been made diabetic by an intravenous injection of 50 mg/kg streptozocin 1 week before mating. The rats were killed on day 21 of pregnancy, and the live fetuses were examined for external, skeletal, and visceral malformations. The maternal and fetal blood glucose levels were the same in all diabetic groups. The maternal Mg levels in groups 2 and 3 were the same as in controls, but definitely lower in groups 4-6. Embryotoxicity (embryonic deaths, delayed development, congenital malformations) was higher in the groups fed the purified diet than in group 2, but without a clear relation to the dietary Mg levels. We cannot draw any conclusions about the effects of Mg deficiency in diabetic pregnancy from our results, but they show that the quality of the diet is of major importance in the manifestation of embryotoxicity in diabetes.     

Developmental outcome of offspring of pregestational diabetic mothers

The aim of this study was to investigate the one-year developmental outcome of offspring of mothers with pregestational diabetes mellitus (PGDM). We prospectively evaluated 31 women with PGDM (21 with type 1 DM and 10 with type 2 DM) and 41 nondiabetic controls during pregnancy and for one year follow-up. Data showed that offspring of mothers with PGDM scored lower than controls in all aspects of development--mental, psychomotor, and exploration/orientation. Despite the good metabolic control of the mothers with PGDM, their offpsring showed a less favorable developmental outcome at one year than infants of nondiabetic mothers. MDI score and PDI score were significantly lower in the diabetic group than in the controls (91.04 vs 98.15, p<0.05 and 85.15 vs 95.54, p<0.05, respectively). In addition, the orientation/engagement score was lower in the diabetic group as compared with the nondiabetic group (41.04 vs 45.50, p<0.05). Whereas no significant difference was found between the type 1 and type 2 groups with regard to the MDI score, type 2 infants scored lower on the PDI than infants in the type 1 group (78.1 vs 89.3) but higher on the motor quality score (34.0 vs 31.3). These preliminary findings support the need for ongoing large scale developmental follow-up studies of offspring born to diabetic mothers in order to elucidate whether they have cognitive impairment later in life.     

Extra pelvic ossification centers in thanatophoric dysplasia and platyspondylic lethal skeletal dysplasia-San Diego type

The platyspondylic lethal skeletal dysplasias (PLSD) are a group of heterogeneous disorders including thanatophoric dysplasia (TD) and the TD variants (San Diego, Torrance, and Luton types). TD is the most common form and has been divided into two subtypes (TD1 and TD2) based on clinical and radiologic criteria and analysis of mutations in the fibroblast growth factor receptor 3 (FGFR3) gene. The variants are distinguished from TD by characteristic radiographic and chondro-osseous morphologic features. We have recently identified FGFR3 mutations in PLSD-San Diego type (PLSD-SD) which are identical to those found in TD1, but the known TD FGFR3 mutations were not found in the other PLSD variants. After reviewing radiographs from 32 cases of PLSD-SD and 47 cases of TD with gestational ages under 24 weeks, we noted novel accessory ossification centers in the ischia of 18 cases of PLSD-SD and 44 of TD, and the ilia in 18 cases of PLSD-SD and 20 of TD. Only three cases of TD and five cases of PLSD-SD did not have extra pelvic ossification centers. At a gestational age greater than 24 weeks, the extra centers are fused with the main bone. The radiographic appearance and chondro-osseous morphology of cases with and without accessory pelvic ossification centers were otherwise indistinguishable. Morphologically, the accessory pelvic ossification centers resulted from membranous ossification. Extra pelvic ossifications are a common radiographic finding in TD and PLSD-SD. Received/accepted: 6 May 1998     

Uteroplacental insufficiency alters liver and skeletal muscle branched-chain amino acid metabolism in intrauterine growth-restricted fetal rats

Uteroplacental insufficiency causes intrauterine growth restriction (IUGR) and decreases plasma levels of the branched-chain amino acids in both humans and rats. Increased fetal oxidation of these amino acids may contribute to their decline in the IUGR fetus. The rate-limiting step of branched-chain amino acid oxidation is performed by the mitochondrial enzyme branched-chain alpha-keto acid dehydrogenase (BCKAD), which is regulated by a deactivating kinase. We therefore hypothesized that uteroplacental insufficiency increases BCKAD activity through altered mRNA and protein levels of BCKAD and/or the BCKAD kinase. In IUGR fetal liver, BCKAD activity was increased 3-fold, though no difference in hepatic BCKAD protein or mRNA levels were noted. Hepatic BCKAD kinase mRNA and protein levels were significantly decreased in association with the increase in BCKAD activity. In IUGR fetal skeletal muscle, BCKAD mRNA levels were significantly increased. IUGR skeletal muscle BCKAD protein levels as well as BCKAD kinase mRNA and protein levels were unchanged. We also quantified mRNA levels of two amino acid transporters: LAT1 (system L) and rBAT (cysteine and dibasic amino acids). Both hepatic and muscle LAT1 mRNA levels were significantly increased in the IUGR fetus. We conclude that uteroplacental insufficiency significantly increases hepatic BCKAD activity in association with significantly decreased mRNA and protein levels of the deactivating kinase. We speculate that these changes contribute to the decreased serum levels of branched-chain amino acids seen in the IUGR fetus and may be an adaptation to the deprived milieu associated with uteroplacental insufficiency.     

Correlations between the intrauterine metabolic environment and blood pressure in adolescent offspring of diabetic mothers

OBJECTIVE: To investigate associations between maternal diabetes and blood pressure (BP), obesity, impaired glucose tolerance, and serum lipids in offspring and whether these parameters correlate with metabolism during pregnancy. STUDY DESIGN: Body mass index, BP, serum glucose, and insulin during an oral glucose tolerance test, and lipid concentrations were measured in 99 offspring of diabetic mothers (ODM) and 80 members of a control group. RESULTS: ODM were more obese (body mass index 22.5 +/- 5.6 vs 20.3 +/- 4.0 kg/m(2)) and had higher systolic (8 mm Hg) and mean arterial BP (4 mm Hg) but similar diastolic BP compared with the control group. ODM had higher 2-hour glucose (6.6 +/- 1.3 vs 5.7 +/- 0.9 mmol/L) and insulin (580 +/- 544 vs 377 +/- 239 pmol/L) concentrations but lower fasting concentrations of low-density lipoprotein (2.54 +/- 0.67 vs 2.82 +/- 0.70 mmol/L) and total cholesterol (4.01 +/- 0.80 vs 4.40 +/- 0.78 mmol/L). In both groups body mass index, triglycerides, and fasting and 2-hour glucose concentrations showed correlations with BP measurements. Fasting insulin was correlated with BP readings only in the ODM. Correlations were found between second- and third-trimester maternal free fatty acid concentrations and diastolic and mean arterial BP. Third-trimester beta-hydroxybutyrate was correlated with mean arterial BP. CONCLUSIONS: In ODM, abnormalities in weight and glucose tolerance are associated with abnormal maternal metabolism. Higher BP is an additional abnormality associated with fetal overnutrition.     

Glucose tolerance of 2- to 5-yr-old offspring of diabetic mothers

The aim of this study was to determine the prevalence of and some risk factors for impaired glucose tolerance (IGT) in 2- to 5-yr-old offspring of diabetic mothers (ODM). The glucose tolerance of 51 offspring born to women with pregnancies complicated by diabetes (type 1) and of 109 children of the control group was analyzed. Our results showed that the fasting glycemia of ODM was similar, when compared to the controls, but 2 h after the glucose loading the glycemia of ODM was significantly higher than that in the control group (5.47 +/- 1.79 mmol/L vs. 4.86 +/- 1.13 mmol/L). Normal glucose tolerance was found in 68.6% of ODM and 86.2% of controls; IGT was found in 17.6% of ODM and 4.6% of controls. Children with macrosomia at birth or overweight at 2-5 yr had IGT at 2-5 yr more often than children with normal weight at birth or normal weight at 2-5 yr. A significant, though relatively low, positive correlation was found between the duration of breastfeeding and fasting glycemia (r=0.241, p <0.01), and positive correlation was found between the duration of breastfeeding and glycemia 2 h after glucose loading (r=0.458, p=0.002) in the offspring of diabetic mothers. In conclusion, the average glycemia of ODM after glucose loading was higher than that in the control group. Macrosomia after birth, overweight, and obesity in childhood had a significant influence on the glucose tolerance of the ODM. The results of the oral glucose tolerance test correlated with the length of breastfeeding.     

Prenatal exposure to IL-1beta results in disturbed skeletal growth in adult rat offspring

Events occurring early in life or prenatally are able to play important roles in the pathogenesis of diseases in adult life. Different sorts of stress or hormonal influences, during particular periods of pregnancy, may result in persistent or transient changes in physiology. IL-1 is a multifunctional cytokine that is involved in bone metabolism. The aim of the present study was to investigate whether exposure to IL-1beta during fetal life has any effect on skeletal growth or bone mineral density in adult rat offspring. Pregnant rats were given intraperitoneal injections of IL-1beta, 1 microg/rat, or saline on days 8, 10, and 12 of gestation. Male IL-1-exposed offspring showed reduced height, areal bone mineral density, and bone mineral content at vertebra L5. Tibial length was reduced in both male and female offspring. Peripheral quantitative computed tomography analyses revealed reduced cortical bone mineral content caused by a decreased cortical cross-sectional area as a result of a decreased cortical thickness, whereas there was no reduction in the amount of trabecular bone in the tibia of male offspring. Our results demonstrate that prenatal exposure to IL-1 can induce specific programming of skeletal tissue. In conclusion, prenatal IL-1 exposure results in decreased skeletal growth and a reduced amount of cortical bone but unchanged trabecular bone mineral density in adult rat offspring.     

Assessment of skeletal age in the first year of life on basis of the caput humeri ossification centres

A new procedure has been worked out to estimate skeletal maturity in infancy. The size of the caput humeri ossification centres was determined with the help of a pattern set from the antero-posterior chest roentgenogram. In each month of the first year of life 100 examinations were carried out and from their data percentile lines were constructed for every month of life.     

Increased renal tubular reabsorption of calcium and magnesium by the offspring of diabetic rat pregnancy

Diabetic pregnancy has a marked influence on offspring calcium and magnesium homeostasis. Urinary excretion of calcium and magnesium is reduced, yet offspring of diabetic pregnancy exhibit hypomagnesemia and hypocalcemia. The aim of this study was to measure renal hemodynamic and tubular function in the offspring of diabetic (OD) and control, nondiabetic (OC) rats at 4 and 8 wk of age to determine the glomerular and tubular mechanisms through which renal calcium and magnesium handling are programmed in utero. The fraction of filtered calcium that was excreted was significantly lower in OD at both 4 and 8 wk of age [8 wk: OC (n = 6), 11.8 +/- 2.9 versus OD (n = 5), 4.3 +/- 0.6%; p < 0.05] and that of magnesium was lower at 8 wk of age [OC (n = 6), 42.4 +/- 7.5 versus OD (n = 5), 13.0 +/- 1.7%; p < 0.01]. This increased reabsorption occurred despite an elevated GFR in OD. These findings clearly indicate that tubular reabsorptive mechanisms for calcium and magnesium are increased markedly in OD. Serum PTH concentration was reduced in 8-wk-old OD [OC (n = 7), 539.4 +/- 142.1 versus OD (n = 9), 174.3 +/- 69.4 pg/ml; p < 0.05], consistent with previous reports in human infants. Taken together, these observations suggest that the basis for the altered renal magnesium and calcium handling in OD involves increased tubular transport activity and possibly increased sensitivity of these mechanisms to PTH.     

Effect of methotrexate and folinic acid on skeletal growth in mice

AIM: To investigate whether chronic administration of medium doses of methotrexate (MTX) causes suppression of skeletal growth in young mice and to determine whether folinic acid supplementation could reverse this effect. METHODS: Four equal groups of Balb/c young male mice (6 animals in each group; mean body weight 11.9 +/- 0.25 g, in their rapid growth phase) were subjected to the following drug treatment for a period of 3 wk. Group 1 was given intraperitoneal MTX (3.5 mg kg(-1) body weight) every second day. Group 2 received folinic acid (7.0 mg kg(-1) body weight) intraperitoneally every second day. Group 3 was given both drugs (MTX every second day and folinic acid 8 h post-MTX injection). Group 4 was injected with physiological saline every other day to serve as a control group. Total body weight of the animals in each group was monitored every second day for the entire study period. The animals were sacrificed, the bilateral femurs and tibias of each animal were harvested and X-rays of the bones were taken. The length of each femur and tibia was measured using a micrometer. Measurements from the radiographs were also recorded using image analysis software. The MTX concentrations in the plasma and the folate levels in erythrocytes were determined. The heights of the distal femoral and the proximal tibial growth plate for each animal were measured on histological tissue sections. RESULTS: Mean lengths of both the tibia and femur of animals were compared in the four treatment groups. A significant decrease in the mean lengths (one-way ANOVA, p < 0.005) was observed in the group receiving MTX alone. Similarly, there was a significant decrease (p < 0.001) in the height of the femoral and tibial growth plate in this group when compared with the other groups. The main effect of MTX seemed to be on the hypertrophic proliferative zone of chondrocytes in the growth plate. Furthermore, animals in this MTX-treated group also showed increased levels of MTX in plasma and low levels of erythrocyte folate. CONCLUSION: These data show that chronic administration of MTX induces suppression of skeletal growth in mice, possibly through the inhibition of the pathway of de novo DNA synthesis. Folinic acid treatment following MTX administration appears to reverse this growth inhibition. Based on these observations, children suffering from juvenile rheumatoid arthritis, osteosarcoma or acute lymphoblastic leukaemia and receiving MTX over long periods of time could be at risk of short-term suppression of skeletal growth. If this is the case, it is possible that they could benefit from dietary supplementation with folinic acid.     

Placental growth and glycogen metabolism in streptozotocin diabetic rats

Placental glycogen metabolism was investigated in rat pregnancies complicated by streptozotocin-induced diabetes mellitus. Both diabetic and control placentas had increasing glycogen concentration from day 14 to day 16, after which glycogen concentration declined rapidly. The diabetic placentas had significantly elevated glycogen concentration when compared to controls from day 16 through term (day 22). Near term, when control glycogen content fell close to zero, the diabetic placentas still had appreciable glycogen levels. Total phosphorylase activity in the diabetic placentas was significantly higher than control values from day 16-22. Phosphorylase A activity, however, was lower in the diabetic placentas late in gestation, corresponding to the increased glycogen concentration seen at that time. Diabetic placentas had increased total synthase activity on the final 3 days of gestation, although synthase A activity was lower than corresponding control values. The placentas in this model are markedly increased in size late in gestation. No difference in protein concentration or protein/DNA ratio was noted. Total DNA content per placenta was significantly increased in the diabetic placentas after day 16 when compared to controls. Placental DNA in the diabetics continued to increase until day 18-19 of gestation, whereas DNA content in control placentas remained constant after day 16. Thus, the diabetic placentas apparently continue the process of DNA replication after DNA synthesis is complete in the controls.