Comparative analysis of two different models of swimming applied to pregnant rats born small for pregnant age

Iron Supplementation and Exercise During Pregnancy: Effects on Behavior and the Dopaminergic System

Although it is known that regular physical activity is recommended as part of a healthy lifestyle, the number of data concerning efficacy of exercise and your relationship with a demand for iron during pregnancy is limited. The purpose of this study was to evaluate the relationship between iron supplementation and exercise during pregnancy on the behavior of rats. Molecular variables dopamine transporter (DAT) and dopamine receptor (D2) related to the locomotor behavior in response to the exercise and the iron supplemented diet were investigated. Sixty-day-old female Wistar rats were used. The pregnant rats were distributed into the following groups: standard diet (SD, n = 7), iron supplementation (IS, n = 9), exercise (EX, n = 10), and exercise + iron supplementation (EX + IS, n = 9). All rats in both the pregnant and non-pregnant groups were submitted to open-field tests. The iron supplementation diet was shown to reduce locomotor behaviors, with reduced central and peripheral ambulation, reduced rearing, and increased freezing. On the other hand, physical exercise caused an increase in central and peripheral ambulation, and in rearing. The expression of the D2 receptor protein and the dopamine transporter DAT did not show changes with the interventions over 21 days of pregnancy. In this context, the present study demonstrated that both iron supplementation and exercise exerted an influence during pregnancy on the behavior of rats, however, with different effects.

Effect of swimming exercise, insulin-associated or not, on inflammatory cytokines, apoptosis, and collagen in diabetic rat placentas

Physical exercise is an important therapeutic agent for women with diabetes during gestation. However, its histophysiological consequences for the placenta remain unclear. In this study, we evaluated the expression of VEGF-A, IL1ß, TNFα, and type I collagen in the placentas of diabetic rats subjected to a swimming program. Thirty rats were divided into the following groups: CG, pregnant nondiabetic rats; CEG, nondiabetic pregnant rats subjected to swimming; DG, pregnant diabetic rats; DEG, pregnant diabetic rats subjected to swimming; DIG, pregnant diabetic rats treated with insulin; DIEG, pregnant diabetic rats treated with insulin and subjected to swimming. Diabetes was induced using streptozotocin [50 mg/kg intraperitoneally (i.p.)], and insulin was administered at a dose of 5 U/day i.p. (2 U at 10 am and 3 U at 7 pm) in the DIG group; in the DIEG group, insulin was administered at a dose of only 2 U/day at 7 pm. The rats were sacrificed on the 20th day of gestation. There was an increase in the expression of IL-1β, TNF-α, VEGF-A, and type I collagen and a higher apoptotic index in the placentas of the DG and DEG groups, but there was a reduction in glycemia in the latter group. In the DIG and DIEG groups, the levels remained similar to those of the control; however, in these groups the reduction was more significant for all analyzed parameters. Therefore, in rats induced to diabetes during pregnancy, swimming, although reducing glycemic levels, did not prevent immunohistochemical changes in the placenta, suggesting the need for a multidisciplinary protocol associated with traditional pharmacological treatment.

Influence of Swimming Program on the Blood Pressure of Pregnant Hypertensive Rats and Their Fetuses

The hypertension incidence and its complication on pregnant women are growing and can lead to adverse consequences on their fetuses. However, it is known that regular exercise practice can be healthful to hypertensive pregnant women but harmful to fetal growth. So, the objective of this study was to evaluate the effects of exercise beginning before pregnancy or during pregnancy on the maternal blood pressure and reproductive outcome and on the fetal development of spontaneously hypertensive rats (SHR). Pregnant SHR were randomly distributed into three experimental groups: (1) SHR-Control, non-exercised; (2) SHR-Ex0, rats submitted to physical exercise (swimming program) from day zero to 20 of pregnancy; (3) and SHR-ExPr, rats submitted to swimming program before and during pregnancy. At end of pregnancy (day 21), the rats were anesthetized, and reproductive parameters and fetal development were assessed. Blood pressure was reduced at the end of pregnancy in all the groups. Regardless of swimming exposure time, there was reduced maternal weight gain. The exercise decreased fetal weight at term pregnancy, with a higher percentage of small for gestational age (SGA) fetuses and lower number ossification sites, indicating intrauterine growth restriction (IUGR). In conclusion, our findings provide insight to support that swimming exercise in pregnant SHR impairs fetal development, causing IUGR and visceral malformations. Therefore, the indication of physical exercise must be defined very carefully, as it can compromise fetal development.

Swimming Program on Mildly Diabetic Rats in Pregnancy

The present study aims to confirm if the moderate-intensity swimming has successful glycemic control and non-toxic oxidative stress levels and to verify the influence on pancreatic adaptations, embryo implantation, and placental efficiency. Female Wistar rats were randomly distributed to obtain mildly diabetic by streptozotocin induction at birth and the non-diabetic females given vehicle. At adulthood, pregnant rats were put at random into sedentary non-diabetic rats (ND); exercise non-diabetic rats (NDEx); sedentary diabetic rats (D); and exercise diabetic rats (DEx). The rats of the groups submitted to moderate intensity carried loads equivalent to 4% of body weight. On day 17 of gestational day, all rats were submitted to oral glucose tolerance test (OGTT). Next day (GD18), the rats were anesthetized and killed to count implantation sites and to collect placentas, blood, and muscle samples for biochemical biomarkers and pancreas for immunohistochemical analysis. The moderate exercise used was not sufficient to stimulate the aerobic pathway but presented positive results on glucose metabolism, lower embryo postimplantation loss, and pancreatic morphology compared with the sedentary diabetic group. However, the DEx group showed muscular damage, decreased antioxidant defense, and lipid peroxidation. Thus, the moderate-intensity exercise reduces glycemic levels during OGTT and causes no damage to non-diabetic rats related to other analyzed parameters in this study. The exercised diabetic rats present better glycemic metabolism in OGTT, islet pancreatic morphology, and embryofetal development. However, it is necessary an adjustment in this exercise intensity to improve the effectiveness of aerobic training for reduction of maternal muscular and lipid membrane damages.

A treatment with a boiled aqueous extract of Hancornia speciosa Gomes leaves improves the metabolic status of streptozotocin-induced diabetic rats

Abstract

Background

Hancornia speciosa is usually used in Brazilian folk medicine to treat diabetes. The hypothesis of the present study is that this medicinal plant exerts beneficial effects on hyperglycemia, preventing diabetic complications. Therefore, the aim of this study was to evaluate the treatment effect of the aqueous extract of H. speciosa leaves on metabolic parameters of diabetic rats.

Methods

The H. speciosa extract (400 mg/Kg) was administered to both nondiabetic and severely diabetic female Wistar rats by gavage. The Oral Glucose Tolerance Test was performed and the area under the curve (AUC) was estimated on day 17 of pregnancy. After 21 days of treatment, the animals were anesthetized and killed to obtain organ weights. Blood samples were collected for an analysis of serum biochemical parameters.

Results

After treatment with the H. speciosa extract, the parameters of nondiabetic rats remained unchanged. In treated diabetic rats, glycemia, AUC, dyslipidemia parameters, and relative organ weights were decreased compared with nontreated diabetic rats. Severely diabetic rats showed decompensated hyperglycemia, polydipsia, hyperphagia and dyslipidemia. However, the aqueous extract of H. speciosa leaves decreased diabetes complications (indicating a lack of toxicity), reduced blood glucose levels, and exerced lipid-lowering effects.

Conclusion

Based on or findings, the H. speciosa leaf extract may be a safe and promising candidate treatment for diabetes and other diseases.

Is willingness to exercise programmed in utero? Reviewing sedentary behavior and the benefits of physical activity in intrauterine growth restricted individuals

OBJECTIVE

The literature suggests that a fetus will adapt to surrounding adversities by optimizing its use of energy to improve survival, ultimately leading to the programming of the individual's energy intake and expenditure. While recent reviews focused on the fetal programming of energy intake and food preferences, there is also some evidence that fetal adversity is associated with diminished physical activity levels. Therefore, we aimed to review (a) the evidence for an association between being born with intrauterine growth restriction and sedentarism over the life-course and (b) the potential benefits of physical activity over cardiometabolic risk factors for this population.

SOURCES

PubMed, Scielo, Scopus and Embase.

SUMMARY OF FINDINGS

Most clinical studies that used objective measures found no association between intrauterine growth restriction and physical activity levels, while most studies that used self-reported questionnaires revealed such relationships, particularly leisure time physical activity. Experimental studies support the existence of fetal programming of physical activity, and show that exposure to exercise during IUGR individuals' life improves metabolic outcomes but less effect was seen on muscle architecture or function.

CONCLUSIONS

Alterations in muscle strength and metabolism, as well as altered aerobic performance, may predispose IUGR individuals to be spontaneously less physically active, suggesting that this population may be an important target for preventive interventions. Although very heterogeneous, the different studies allow us to infer that physical activity may have beneficial effects especially for individuals that are more vulnerable to metabolic modifications such as those with IUGR.

Experimental diabetes impairs maternal reproductive performance in pregnant Wistar rats and their offspring

The aim of this study was to determine the effect of mild hyperglycemia on metabolism during pregnancy, the maternal reproductive performance, and the characteristics of the offspring in neonatal mild diabetic-induced Wistar rats. The experimental diabetes model was generated by neonatal streptozotocin administration (100 mg of streptozotocin/Kg bw/sc) in female Wistar rats. At adulthood, the control and diabetic group were mated. At the 20th day of gestation, a maternal and fetal blood sample were collected for biochemical measurement. The maternal livers, fetal livers, and placenta were removed for oxidative stress measurements. Maternal reproductive outcomes and fetal and placental morphometric measurements were analyzed. The fetuses were classified as small, appropriate, and large for pregnancy age, and examined for the presence of external anomalies. The diabetic group showed mild hyperglycemia, altered glucose tolerance, increased total cholesterol, triglycerides, and hemoglobin A1c during pregnancy. At the 20th day of gestation the diabetic mothers presented increased reabsorptions and embryonic losses before and after implantation, reduced corpora lutea number, litter size, implantation sites, live fetuses, and decreased efficiency of implantation rate. Similarly, the offspring showed reduced fetal, craniofacial, and placental dimensions, in addition to a higher proportion of small fetuses for pregnancy age. Mild hyperglycemia during pregnancy did not generate marked oxidative stress in the mother, and in fetal liver and placenta decreased antioxidant activity was evident by significant consumption of reduced glutathione. Mild diabetes led to a negative impact on maternal reproductive performance and characteristics of the offspring. This experimental model reproduced maternal and fetal outcomes of pregnant rats presenting controlled diabetes.

ABBREVIATIONS

bw: body weight; sc: subcutaneous; DM: diabetes mellitus; STZ: streptozotocin; OGTT: oral glucose tolerance test; ITT: insulin tolerance test; GSH: glutathione; MDA: malondialdehyde; AOPPs: advanced oxidation protein products; TBARs: thiobarbituric acid reaction; SPA: small for pregancy age; APA: appropriate for pregnancy age; LPG: large for pregnancy age; ROS: reactive oxygen species.