Effect of Diabetes on Circulating Pancreatic Hormones in Pregnant Rats and Their Offspring.

The aim of the study was to investigate the role of diabetic intrauterine environment on circulating insulin, glucagon, and somatostatin levels in pregnant rats, fetuses, and offspring. Diabetes was induced in female Wistar rats by streptozotocin at birth or as adult and the animals were assigned into: control (C); mildly diabetic (MD); and severely diabetic (SD). The rats were mated and distributed into 2 subgroups: euthanasia at day 21 of pregnancy and at day 10 postpartum. Both MD and SD dams showed impaired oral glucose tolerance. SD dams had lower body weight and insulin levels compared to C and MD dams. SD fetuses presented hyperglycemia and reduction of insulin and glucagon levels compared to C and MD fetuses. SD newborns had diminished total pancreatic insulin and plasma somatostatin compared to the other groups. MD dams and fetuses had lower glucagon and somatostatin levels compared to C dams. MD offspring had maintained lower somatostatin levels to neonatal period. Diabetes causes alterations in circulating levels of pancreatic hormones in the mother and offspring.

Diabetes induced immunological and biochemical changes in human colostrum.

AIM: This article describes the changes and relationships between biochemical and immunological parameters in the colostrum and serum of diabetic women. METHODS: Colostrum and blood samples were collected from 30 diabetic and 15 normoglycaemic women. Glucose, total protein, antibody, complement proteins (C3 and C4), fat and calorie content, amylase, lipase and superoxide dismutase (SOD) were determined. RESULTS: Glucose was higher in both the colostrum and serum of diabetic mothers compared to that of their normoglycaemic counterparts. In both groups, total protein was higher in colostrum than in serum. IgA and IgG were lower in the colostrum of hyperglycaemic mothers, whereas IgM did not vary between the groups. Colostral C3 protein was significantly lower in diabetic mothers, but colostral C4 protein was similar between normoglycaemic and hyperglycaemic mothers. Fat content was lower in the colostrum of the diabetic mothers, although calorie content did not vary between the groups. Amylase was lower in colostrum than in serum in both groups. Lipase was higher in the colostrum and serum of diabetic mothers. Colostral SOD was similar between the groups. CONCLUSIONS: Our results support the hypothesis that the colostrum of diabetic mothers suffers biochemical and immunological alterations that affect the levels of its components.

Effect of exercise on the reproductive outcome and fetal development of diabetic rats.

The aim of this study was to evaluate the effect of exercise on pregnancy outcome in streptozotocin-induced diabetic Wistar rats (n = 11 animals/group). These animals were randomly assigned to sedentary (G1) and exercised groups, beginning from day 0 (G2) or 7 (G3) to day 20 of pregnancy. The moderate exercise was a swimming programme. At day 21 of pregnancy, all rats were anaesthetized and killed to obtain pregnancy outcome data. All rats presented glycaemia higher than 300 mg/dl, regardless of the exercise training. The G3 group showed higher live fetus number per implantation site and lower resorption number per implantation site compared with the G1 group. The fetal and placental mean weights per litter and the total number of ossification sites were significantly lower in the exercised groups (P < 0.05). Placental index was lower in the G2 and G3 groups compared with the G1 group. The occurrence of skeletal anomalies indicated that exercise increased the number of altered fetuses. Thus, moderate exercise achieved better outcomes by increasing the number of live births and decreasing resorption. However, exercise increased skeletal anomalies and decreased fetal and placental weights.

Effect of Bauhinia forficata aqueous extract on the maternal-fetal outcome and oxidative stress biomarkers of streptozotocin-induced diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Bauhinia forficata Link, commonly known as "paw-of-cow", is widely used in Brazilian folk medicine for the treatment of diabetes. AIM OF THIS STUDY: To evaluate the effect of Bauhinia forficata treatment on maternal-fetal outcome and antioxidant systems of streptozotocin-induced diabetic rats. MATERIALS AND METHODS: Virgin female Wistar rats were injected with 40 mg/kg streptozotocin before mating. Oral administration of an aqueous extract of Bauhinia forficata leaves was given to non-diabetic and diabetic pregnant rats at increasing doses: 500 mg/kg from 0 to 4th day of pregnancy, 600 mg/kg from 5th to 14th day and 1000 mg/kg from 15th to 20th day. At day 21 of pregnancy the rats were anaesthetized with ether and a maternal blood sample was collected for the determination superoxide dismutase (SOD) and reduced glutathione (GSH). The gravid uterus was weighed with its contents and fetuses were analyzed. RESULTS AND CONCLUSION: The data showed that the diabetic dams presented an increased glycemic level, resorption, placental weight, placental index, and fetal anomalies, and reduced GSH and SOD determinations, live fetuses, maternal weight gain, gravid uterine weight, and fetal weight. It was also verified that Bauhinia forficata treatment had no hypoglycemic effect, did not improve maternal outcomes in diabetic rats, but it contributed to maintain GSH concentration similarly to non-diabetic groups, suggesting relation with the decreased incidence of visceral anomalies.

Morphological changes in rat rectus abdominis muscle induced by diabetes and pregnancy.

The urethral muscle of diabetic pregnant rats is affected by long-term mild diabetes and short-term severe diabetes, which plays a crucial role in the pathogenesis of pelvic floor disorders. We hypothesized that muscles outside the pelvis are subject to similar changes. The current study aimed at analyzing the effects of long-term mild and short-term severe diabetes on the structure and ultrastructure of fiber muscles and collagen in rats' rectus abdominis (RA) muscle. Therefore, the RA muscle of virgin, pregnant, long-term mild diabetic, short-term severe diabetic, long-term mild diabetic pregnant and short-term severe diabetic pregnant 3-month-old Wistar rats were collected. The structure was analyzed by picrosirius red staining, immunohistochemistry for fast and slow muscle fibers and transmission electron microscopy. We investigated two levels of STZ- induced diabetes: long-term mild diabetes (blood glucose level: 120-200 mg/dL) and short-term severe diabetes (blood glucose level >300 mg/dL). Long-term mild diabetic pregnant and short-term severe diabetic pregnant rats had decreased fast fibers and increased slow fibers, disrupted areas of sarcomere, intermyofibrillar mitochondria and myelin figures in the RA muscle. Both groups enabled us to analyze the specific influence of pregnancy, separately from diabetes. The current study demonstrated that diabetes and pregnancy induced intramuscular transformation and reorganization of RA muscle with a switch of fiber type adjusting their architecture according to intensity and duration of hyperglycemic insult within pregnancy.

Small-for-pregnancy-age rats submitted to exercise: DNA damage in mothers and newborns, measured by the comet assay.

BACKGROUND: Fetal impairment caused by a deleterious intrauterine environment may have long-term consequences, such as oxidative stress and genetic damage. Rats born as small-for-gestational-age (SPA) were submitted to exercise (swimming) before and during pregnancy. The animals exhibited glucose intolerance, reduced general adiposity, and increased maternal and offspring organ weight, showing the benefit of exercise for these rats. We hypothesised that regular exercise in SPA during gestation could prevent DNA damage in these animals and in their offspring, contributing to altered fetal programming of metabolism in the offspring. Severe diabetes was induced by streptozotocin treatment, to obtain SPA newborns. At adulthood, pregnant SPA rats were randomly distributed into two groups: exercised (SPAex - submitted to swimming program) or not-exercised (SPA - sedentary rats). Post-partum, blood was collected for analysis of DNA damage (comet assay) and oxidative stress. SPAex rats presented lower DNA damage levels, decreased lipid peroxidation, and a lower rate of newborns classified as large-for-pregnancy-age. DNA damage was also lower in SPAex newborns. We conclude that swimming applied to SPA pregnant rats contributes to decreased DNA damage and lipid peroxidation in the dams, and decreased DNA damage and macrosomia in their offspring.

Effect of Ginkgo biloba on the reproductive outcome and oxidative stress biomarkers of streptozotocin-induced diabetic rats.

The aim of the present study was to evaluate the effect of Ginkgo biloba treatment (EGb 761, 200 mg kg-1 day-1) administered from day 0 to 20 of pregnancy on maternal reproductive performance and on the maternal and fetal liver antioxidant systems of streptozotocin-induced diabetic Wistar rats. On day 21 of pregnancy, the adult rats (weighing approximately 250 +/- 50 g, minimum number = 13/group) were anesthetized to obtain maternal and fetal liver samples for superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and total glutathione (GSH-t) determinations. The uterus was weighed with its contents. The diabetic (G3) and treated diabetic (G4) groups of rats presented significant maternal hyperglycemia, reduced term pregnancy rate, impaired maternal reproductive outcome and fetal-placental development, decreased GSH-Px (G3 = G4 = 0.6 +/- 0.2) and SOD (G3 = 223.0 +/- 84.7; G4 = 146.1 +/- 40.8), and decreased fetal CAT activity (G3 = 22.4 +/- 10.6; G4 = 34.4 +/- 14.1) and GSH-t (G3 = G4 = 0.3 +/- 0.2), compared to the non-diabetic groups (G1, untreated control; G2, treated). For G1, maternal GSH-Px = 0.9 +/- 0.2 and SOD = 274.1 +/- 80.3; fetal CAT = 92.6 +/- 82.7 and GSH-t = 0.6 +/- 0.5. For G2, G. biloba treatment caused no toxicity and did not modify maternal or fetal-placental data. EGb 761 at the nontoxic dose used (200 mg kg-1 day-1), failed to modify the diabetes-associated increase in maternal glycemia, decrease in pregnancy rate, decrease in antioxidant enzymes, and impaired fetal development when the rats were treated throughout pregnancy (21 days).

Intrauterine Growth Restricted Rats Exercised before and during Pregnancy: Maternal and Perinatal Repercussions.

This study aimed at evaluating the effect of swimming before and during pregnancy on rats born with intrauterine growth restriction (IUGR) and their offspring. For this, nondiabetic and streptozotocin-induced severely diabetic (SD) pregnant rats were mated and generated offspring with appropriate (control, C) and small (IUGR) for pregnancy age, respectively. Following that, C and IUGR groups were further distributed into nonexercised control (C), exercised control (Cex), nonexercised IUGR (IUGR), and exercised IUGR (IUGRex). IUGR rats presented lower mating rate than control rats. Regardless of physical exercise IUGR rats presented decreased body weight from birth to lactation. At 90 days of life, IUGR rats presented glucose intolerance. Maternal organ weights were increased and relative adiposity of IUGRex rats was lower than Cex. IUGR and IUGRex offspring presented reduced body weight than C and Cex, respectively. IUGRex dams presented an increased rate of appropriate for pregnancy age newborns. IUGEex male and female offspring relative brain weight was increased compared with Cex. Therefore, swimming before and during pregnancy prevented glucose intolerance, reduced general adiposity, and increased maternal and offspring organ weight in rats, showing the benefit of physical exercise for IUGR rats.

Extracellular HSP70 levels in diabetic environment in rats.

The expression of HSP70 in embryonic cells of mammals and its role for their normal development and protection is an important aspect to be investigated in pregnancy and/or mild diabetes. In this sense, the present study evaluated the effects of mild diabetes on maternal reproductive parameters and HSP70 levels in Wistar rats at different stages of life and in their offspring. Mild diabetes was induced by a beta-cytotoxic drug (streptozotocin) at birth. Four experimental groups were evaluated: at 90 days of age: nonpregnant nondiabetic (ND90) and nonpregnant mild diabetic (D90) female rats, and at term pregnancy: pregnant female rats of both glycemic status were examined (NDP and DP, respectively). The rats were submitted to oral glucose tolerance test, and blood samples were collected for determination of HSP70 levels. In addition, the reproductive performance of pregnant rats was assessed and HSP70 levels determined in their offspring blood samples. The HSP70 levels and maternal reproductive performance presented no difference between ND and D rats, regardless of the life stage. The HSP70 levels were increased in D90 rats and lower in offspring from D rats. Maternal HSP70 levels were positively correlated to the number of dead embryos. In conclusion, mild diabetes did not affect maternal reproductive performance, but high maternal HSP70 levels compromised embryo development. In addition, offspring from D rats exhibited lower HSP70 levels, showing that this protein can be used as an indicator of metabolic consequences of diabetes and predictor of related disorders in adulthood.

Intrauterine Growth Restricted Rats Exercised at Pregnancy: Maternal-Fetal Repercussions.

To evaluate the effect of swimming in pregnant rats born with intrauterine growth restriction (IUGR) and their offspring, IUGR rats were obtained using the streptozotocin-induced severe diabetic (SD) rats. In this study, the nondiabetic parental generation presented 10 rats and diabetic parental generation presented 116 rats. Of these, the mated nondiabetic female rats were 10 and the number of diabetic rats was 45. In relation to term pregnancy, there were 10 animals in the nondiabetic group and 15 rats in the diabetic group. In the offspring of SD rats (IUGR group), 43 females were classified as small for pregnancy age, 19 rats were classified as appropriate for pregnancy age, and 0 female was classified as large for pregnancy age. The nondiabetic and SD pregnant rats generated offspring with appropriate (control [C]) and small (IUGR) weight for pregnancy age, respectively. At adult life, the C group was maintained as nonexercised C group and IUGR rats were distributed into 2 subgroups, namely, nonexercised (IUGR) and exercised (IUGRex). The rate of mated rats in the IUGR group was reduced compared to the C group. During pregnancy, the IUGR rats presented hyperinsulinemia, impaired reproductive outcomes, decreased body weight, hypertriglyceridemia, and hyperlactacidemia. The IUGRex presented reduced insulin and triglyceride levels. Thus, swimming improved lipid metabolism and increased insulin sensitivity. However, the offspring showed retarded growth, reinforcing the need to stimulate the exercise practice in women under supervision with different professional expertise to promote appropriate gestational conditions and improve perinatal outcomes.

Study of the embryotoxic effects of an extract of rosemary (Rosmarinus officinalis L.).

Extracts of rosemary, Rosmarinus officinalis L., have been used in folk medicine as a diuretic, an emenagogue, an antispasmodic and its aqueous extract does not present toxicity to man, presenting, however, abortive effects. In order to evaluate if this plant induces abortion and/or interferes with the normal development of the concepts, doses of 26 mg of a 30% (w/v) R. officinalis aqueous extract (13 mg solids/ml) made with leaves, flowers and stem were administered daily by gavage during two different periods of Wistar rat pregnancy. One group of animals (N = 12) received the extract from days 1 to 6 of pregnancy (preimplantation period) and another group (N = 14) received the same extract from days 6 to 15 of pregnancy (organogenic period). Control groups (N = 12) received saline in the same volume and during the same periods as their respective experimental groups. The animals were sacrificed at term. The treatment of the dams during either the preimplantation or the organogenic period did not cause significant changes in the postimplantation loss or in the number of anomalies or malformations of the term fetuses, which also showed a similar degree of development when compared with the respective controls. The percent of preimplantation loss in the group treated before embryo implantation increased, although the difference was not significant compared to the control. This result suggests that rosemary extract may present an anti-implantation effect without interfering with the normal development of the concept after implantation.

Streptozotocin-induced diabetes models: pathophysiological mechanisms and fetal outcomes.

Glucose homeostasis is controlled by endocrine pancreatic cells, and any pancreatic disturbance can result in diabetes. Because 8% to 12% of diabetic pregnant women present with malformed fetuses, there is great interest in understanding the etiology, pathophysiological mechanisms, and treatment of gestational diabetes. Hyperglycemia enhances the production of reactive oxygen species, leading to oxidative stress, which is involved in diabetic teratogenesis. It has also been suggested that maternal diabetes alters embryonic gene expression, which might cause malformations. Due to ethical issues involving human studies that sometimes have invasive aspects and the multiplicity of uncontrolled variables that can alter the uterine environment during clinical studies, it is necessary to use animal models to better understand diabetic pathophysiology. This review aimed to gather information about pathophysiological mechanisms and fetal outcomes in streptozotocin-induced diabetic rats. To understand the pathophysiological mechanisms and factors involved in diabetes, the use of pancreatic regeneration studies is increasing in an attempt to understand the behavior of pancreatic beta cells. In addition, these studies suggest a new preventive concept as a treatment basis for diabetes, introducing therapeutic efforts to minimize or prevent diabetes-induced oxidative stress, DNA damage, and teratogenesis.

Mild diabetes models and their maternal-fetal repercussions.

The presence of diabetes in pregnancy leads to hormonal and metabolic changes making inappropriate intrauterine environment, favoring the onset of maternal and fetal complications. Human studies that explore mechanisms responsible for changes caused by diabetes are limited not only for ethical reasons but also by the many uncontrollable variables. Thus, there is a need to develop appropriate experimental models. The diabetes induced in laboratory animals can be performed by different methods depending on dose, route of administration, and the strain and age of animal used. Many of these studies are carried out in neonatal period or during pregnancy, but the results presented are controversial. So this paper, addresses the review about the different models of mild diabetes induction using streptozotocin in pregnant rats and their repercussions on the maternal and fetal organisms to propose an adequate model for each approached issue.

Genotoxicity evaluation in severe or mild diabetic pregnancy in laboratory animals.

This study aimed to evaluate the genotoxicity (DNA damage levels) in lymphocyte samples from pregnant Wistar rats with severe or mild diabetes and in whole blood samples from their newborns. Wistar female rats (1 and 90 days of age) and male rats (approximately 90 days of age) were used. The experiment consisted of 2 experimental groups (n=8 animals/group): 1) rats with severe diabetes, 2) rats with mild diabetes. For mild diabetes induction, the rats received streptozotocin (STZ) subcutaneously (100 mg/kg body weight) at day of birth, and those showing glycemia from 120 to 300 mg/dL in their adult life were included. For induction of severe diabetes, adult rats received 40 mg/kg STZ (intravenous route), and those showing glycemia > 300 mg/dL were included. At day 21 of pregnancy, the rats were anesthetized and euthanized for removal of maternal and fetal blood samples for determination of the oxidative DNA damage by applying Endo III and Fpg using the comet assay. Thus, the rats with mild diabetes and their offspring showed higher Fpg-sensitive sites, reflecting the damage resulting from hyperglycemia. The rats with severe diabetes and their offspring showed higher oxidative DNA damage detected by Fpg and Endo III-sensitive sites, showing general repercussions related to diabetes. The enzymatic treatment for DNA damage evidenced that the maternal repercussions of diabetes are associated with oxidative DNA damage of their newborn, which was not reflected using only the analysis of DNA damage free of the enzymes.

Effect of Morus nigra aqueous extract treatment on the maternal-fetal outcome, oxidative stress status and lipid profile of streptozotocin-induced diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Morus nigra, commonly known as black mulberry, is widely used in Brazilian folk medicine for the diabetes treatment. AIM OF THIS STUDY: To evaluate the effect of Morus nigra aqueous extract treatment on maternal lipid and oxidative stress profile, reproductive outcomes, and also fetal anomaly incidence from diabetic and non-diabetic rats. MATERIALS AND METHODS: Diabetes was induced by streptozotocin (40 mg/kg) in virgin female Wistar rats. Morus nigra leaf aqueous extract (400 mg/kg) was administered from day 0 to 20 of pregnancy. At day 21 of pregnancy, all rats were anesthetized and killed to obtain blood samples and maternal-fetal data. RESULTS AND CONCLUSION: After treatment with Morus nigra extract, non-diabetic and diabetic rats presented no glycemic changes. Fetuses from diabetic dams, regardless of Morus nigra treatment, were small for pregnancy age. In diabetic dams, plant treatment caused reduced MDA, cholesterol, triglycerides and VLDL levels, and decreased placental index and weight as compared to diabetic group. The fetuses from diabetic rats treated with Morus nigra extract had lower frequency of skeletal and visceral anomalies as compared to diabetic group. Thus, Morus nigra leaf aqueous extract failed to control hyperglycemia in diabetic rats. However, Morus nigra treatment had antioxidant effect, contributing to reduce incidence of internal anomalies in offspring from diabetic dams.

Maternal-fetal outcome, lipid profile and oxidative stress of diabetic rats neonatally exposed to streptozotocin.

BACKGROUND: There is no evidence about the integrated issue on glycemia, lipid profile, oxidative stress, and anomaly frequency of pregnant diabetic rats neonatally exposed to streptozotocin. OBJECTIVE: Evaluating the impact of hyperglycemia in diabetic rats neonatally exposed to streptozotocin on maternal reproductive and fetal outcomes and the relationship with lipid profile and maternal oxidative stress. MATERIAL AND METHODS: Ten 90-day-old female Wistar rats were mated to obtain offspring. Some of these newborns received streptozotocin (70 mg/kg, i. p. - n5-STZ group) and the remainder given only citrate buffer (control group) on their day 5 of life. At adult life, these rats (n=13 animals/group) were mated and, at day 21 of pregnancy, they were killed to obtain a maternal blood samples for biochemical determinations. The gravid uterus was weighed with its contents and fetuses were analyzed. RESULTS: At day 0 of pregnancy, glycemic means of n5-STZ rats were significantly greater compared to those of control rats, but presented fetuses classified as small for pregnancy age. The n5-STZ rats showed increased total cholesterol, triglycerides, MDA concentrations, lower SOD activity and increased frequency fetal visceral anomalies as compared to the control group. CONCLUSION: This study showed that the experimental model used led to mild hyperglycemia during pregnancy, although it did not lead to increased macrosomic fetus rates. The hyperglycemic maternal environment caused metabolic alterations, including increased triglyceride and total cholesterol concentrations, and elevated oxidative stress, contributing to increase fetal visceral anomalies.

Plasma concentrations and placental immunostaining of interleukin-10 and tumor necrosis factor-α as predictors of alterations in the embryo-fetal organism and the placental development of diabetic rats.

Interleukin-10 (IL-10) appears to be the key cytokine for the maintenance of pregnancy and inhibits the secretion of inflammatory cytokines such as tumor necrosis factor-α (TNF-α). However, there are no studies evaluating the profile of these cytokines in diabetic rat models. Thus, our aim was to analyze IL-10 and TNF-α immunostaining in placental tissue and their respective concentrations in maternal plasma during pregnancy in diabetic rats in order to determine whether these cytokines can be used as predictors of alterations in the embryo-fetal organism and in placental development. These parameters were evaluated in non-diabetic (control; N = 15) and Wistar rats with streptozotocin (STZ)-induced diabetes (N = 15). At term, the dams (100 days of life) were killed under anesthesia and plasma and placental samples were collected for IL-10 and TNF-α determinations by ELISA and immunohistochemistry, respectively. The reproductive performance was analyzed. Plasma IL-10 concentrations were reduced in STZ rats compared to controls (7.6 ± 4.5 vs 20.9 ± 8.1 pg/mL). The placental scores of immunostaining intensity did not differ between groups (P > 0.05). Prevalence analysis showed that the IL-10 expression followed TNF-α expression, showing a balance between them. STZ rats also presented impaired reproductive performance and reduced plasma IL-10 levels related to damage during early embryonic development. However, the increased placental IL-10 as a compensatory mechanism for the deficit of maternal regulation permitted embryo development. Therefore, the data suggest that IL-10 can be used as a predictor of changes in the embryo-fetal organism and in placental development in pregnant diabetic rats.

Genotoxicity and fetal abnormality in streptozotocin-induced diabetic rats exposed to cigarette smoke prior to and during pregnancy.

BACKGROUND: Maternal hyperglycemia during early pregnancy is associated with increased risk of abnormalities in the offspring. Malformation rates among the offspring of diabetic mothers are 2-5-fold higher than that of the normal population, and congenital malformations are the major cause of mortality and morbidity in the offspring of diabetic mothers. Metabolic changes, such as hyperglycemia and the metabolites obtained from cigarettes both increase the production of reactive oxygen species (ROS) in the embryo or fetus, causing DNA damage. OBJECTIVE: To evaluate the maternal and fetal genotoxicity, and to assess the incidence of fetal anomaly in diabetic female rats exposed to cigarette smoke at different stages of pregnancy in rats. MATERIAL AND METHOD: Diabetes was induced by streptozotocin administration and cigarette smoke exposure was produced by a mechanical smoking device that generated mainstream smoke that was delivered into a chamber. Female Wistar rats were randomly assigned to: non-diabetic (ND) and diabetic (D) groups exposed to filtered air; a diabetic group exposed to cigarette smoke prior to and during pregnancy (DS) and a diabetic group only exposed to cigarette smoke prior to pregnancy (DSPP). On pregnancy day 21, blood samples were obtained for DNA damage analysis and fetuses were collected for congenital anomaly assessment. Statistical significance was set at p<0.05 for all analysis. RESULTS AND CONCLUSION: Exposure of diabetic rats to tobacco smoke prior to pregnancy increased fetal DNA damage, but failed to induce teratogenicity. Thus, these results reinforce the importance for women to avoid exposure to cigarette smoke long before they become pregnant.

Vascular endothelial growth factor (VEGF) and VEGF-receptor expression in placenta of hyperglycemic pregnant women.

Hyperglycemia occurs in a variety of conditions such as overt diabetes, gestational diabetes and mild hyperglycemia, all of which are generally defined based on the oral glucose tolerance test and glucose profiles. Whereas diabetes has received considerable attention in recent decades, few studies have examined the mechanisms of mild hyperglycemia and its associated disturbances. Mild gestational hyperglycemia is associated with macrosomia and a high risk of perinatal mortality. Morphologically, the placenta of these women is characterized by an increase in the number of terminal villi and capillaries, presumably as part of a compensatory mechanism to maintain homeostasis at the maternal-fetal interface. In this study, we analised the expression of VEGF and its receptors VEGFR-1 (Flt-1) and VEGFR-2 (KDR) in placentas from mildly hyperglycemic women. This expression was compared with that of normoglycemic women and women with gestational and overt diabetes. Immunohistochemistry revealed strong staining for VEGF and VEGFR-2 in vascular and trophoblastic cells of mildly hyperglycemic women, whereas the staining for VEGFR-1 was discrete and limited to the trophoblast. The pattern of VEGF and VEGF-receptor reactivity in placentas from women with overt diabetes was similar to that of normoglycemic women. In women with gestational diabetes, strong staining for VEGFR-1 was observed in vascular and trophoblastic cells whereas VEGF and VEGFR-2 were detected only in the trophoblast. The expression of these proteins was confirmed by western blotting, which revealed the presence of an additional band of 75 kDa. In the decidual compartment, only extravillous trophoblast reacted with all antibodies. Morphological analysis revealed collagen deposition around large arteries in all groups with altered glycemia. These findings indicate a placental response to altered glycemia that could have important consequences for the fetus. The change in the placental VEGF/VEGFR expression ratio in mild hyperglycemia may favor angiogenesis in placental tissue and could explain the hypercapillarization of villi seen in this gestational disturbance.

Effect of obesity on rat reproduction and on the development of their adult offspring.

The aim of the present study was to assess the reproductive parameters of obese Wistar rats and to determine the frequency of their obese adult offspring. Neonatal rats were divided into two groups: F1 generation, induced to obesity by monosodium glutamate (MSG; F1MSG, N = 30), and rats given saline (F1CON, N = 13). At 90 days of age all animals were mated, producing the F2 offspring (F2CON, N = 28; F2MSG, N = 15). Reproductive parameters (fertility, pregnancy, and delivery indexes) were evaluated in F1 rats. F2 newborns were weighed, and the obesity parameter for F1 and F2 generations was determined from months 5 to 7 of life. At month 7, periovarian fat was weighed and no differences were found. Mean newborn weight also did not differ. The F1 and F2MSG groups presented approximately 90% of obese rats since month 5 of life, whereas F1 and F2CON groups presented only 33%. There was no difference in periovarian weight among groups. Although obesity did not affect reproductive parameters, obese dams (F1MSG) were responsible for the appearance of obesity in the subsequent generation. Thus, obesity induced by neonatal MSG administration did not interfere with reproduction, but did provide a viable model for obesity in second-generation adult Wistar rats. This model might contribute to a better understanding of the pathophysiological mechanisms involved in transgenerational obesity.