assessing the physical traits of fetuses obtained from swim-trained pregnant rats

Exploring Maternal Exercise for the Well-Being of Rat Offspring

The Developmental Origins of Health and Disease (DOHaD) concept emerged over the last two decades, which has shown that environmental influences during early development affect the risk of later pathophysiological processes associated with chronic non-communicable disease (NCD), especially diabetes, cardiovascular disease, and some types of cancer1. During the most plastic phase of fetal development, where offspring are exposed to the intrauterine environment, the gene and environment interaction and uteroplacental perfusion are crucial factors of fetal reprogramming2. Previous studies have predominantly utilized animal models to investigate the detrimental effects, such as maternal undernutrition, overnutrition, or obesity during pregnancy, and prenatal exposure to chemicals or hypoxia, on fetal development and long-term phenotypic effects in the offspring3. This produced low birth weight and later growth and produced adverse effects on offspring, including elevated blood pressure, dyslipidemia, and insulin resistance4. Since the rate of overweight and obesity is rapidly increasing among women of reproductive age, establishing effective interventions to prevent the intergenerational transmission of these deleterious maternal disorders is urgently needed, which has an important impact on population health5,6.
Exercise has long been recognized as an important preventive therapeutic for type 2 diabetes, hypertension, and several other diseases7. Exercise during pregnancy has beneficial effects for the mother and confers beneficial effects on offspring, thus reducing the maternal transmission of disease to offspring8. Several years of research have demonstrated exercise&#39;s safety and profound benefits, including substantial reductions in common pregnancy conditions such as gestational diabetes mellitus9,10. Regarding maternal and fetal safety, conducting exercise training and post-nursing protocols is challenging.
David11 et al. described animal exercise models applicable to cardiovascular health research. The three commonly used exercise models, voluntary wheel running, motorized treadmills, and swimming, have advantages and disadvantages. The voluntary wheel running closely mimics the locomotor behavior of rats, enabling them to move according to their circadian rhythm. However, this sort of exercise needs more precise regulation of intensity and duration. The motorized treadmill can control exercise intensity, volume, and duration, but sometimes it needs electric stimulation, which may trigger physical and psychological stress in the animals. Swimming is widely used in rodent studies due to the inherent swimming ability of rats, which can also avoid electric stimulation or mechanical damage to their feet and tails12. In studies on prenatal exercise models13,14, swimming is a commonly used exercise modality. As pregnancy progresses and the abdomen of the rat swells, treadmill and wheel running exercises may cause repeated contact of the abdomen with hard surfaces. In contrast, the water environment in swimming provides buoyancy, reducing the risk of exercise-related injuries for pregnant animals.
This protocol presents the rat breeding methods, how to perform the swimming training during pregnancy, and the post-breeding nursing protocols for pregnant rats after training. This pregnant swimming training model can be applied to a wide range of rat and mouse species, which may thus provide a useful rodent model for future investigation using animal-based models to study the mechanisms regulating the beneficial effects of maternal exercise on offspring health and the benefits of exercise across generations.

Author Spotlight: Enhancing the Offspring Health in Rats with Maternal Exercise During Pregnancy

Swimming Exercise Protocol and Care Methods for Pregnant Rats

Our research delineates rat-breeding methods. Prenatal swimming training produces, and the post-breeding nursing protocols for rats, which will be of good help to the researchers of exercise physiology and the perinatal biology. As pregnancy progresses and the abdomen of the rat swells, treatment and the regularly exercises may cause repeated contact of the abdomen with hard surfaces.In contrast, the water environment in swimming exercise protocol provides buoyancy, reducing the risk of exercise-related injuries for pregnant animals. Maternal obesity can lead to an increase in incidents of cardiovascular and metabolic diseases in offspring. In the future, when we apply this swimming exercise protocol to a high-fat diet, induce the obese, pregnant mice to explore the apt in a tic mag design.and find a new way to curb the intergenerational inheritance of obesity-related diseases.

Assessing the Physical Traits of Fetuses Obtained from Swim-Trained Pregnant Rats

To begin, obtain a swim-trained euthanized pregnant rat. Using a surgical knife, make an incision in the lower abdomen to expose the uterus completely. With forceps and scissors, carefully open the uterus to reveal the fetuses and placentas.Gently peel away the surrounding amnion, preventing any harm to the fetuses. Sequentially, separate fetuses and placentas by their anatomical positions. Using sterile gauze, clean the fetus to eliminate any blood and mucous.Then, weigh the fetus and the placenta. Next, observe the distance between the anus and genitalia. And document the gender, as well as the total number of male and female fetuses.Unfold the curled up fetus. And using a caliper, measure the length while the fetus is lying flat.

assessing-physical-traits-fetuses-obtained-from-swim-trained-pregnant

Research

JoVE Journal

Developmental Biology

36 Views. To begin, obtain a swim-trained euthanized pregnant rat. Using a surgical knife, make an incision in the lower abdomen to expose the uterus completely. With forceps and scissors, carefully open the uterus to reveal the fetuses and placentas.Gently peel away the surrounding amnion, preventing any harm to the fetuses. Sequentially, separate fetuses and placentas by their anatomical positions. Using sterile gauze, clean the fetus to eliminate any blood and mucous.Then, weigh the fe...

Video: Assessing the Physical Traits of Fetuses Obtained from Swim-Trained Pregnant Rats

The developmental origins of health and disease concept highlights the impact of early environments on chronic non-communicable diseases like diabetes, cardiovascular disease, and cancer. Studies using animal models have investigated how maternal factors such as undernutrition, overnutrition, obesity, and exposure to chemicals or hypoxia affect fetal development and offspring health, leading to issues like low birth weight, high blood pressure, dyslipidemia, and insulin resistance. Given the increasing prevalence of overweight and obesity among reproductive-age women, effective interventions are critical. Maternal exercise during pregnancy has emerged as a key intervention, benefiting both mother and offspring and reducing the risk of disease. This study compares the differences of three exercise models on pregnant rats: voluntary wheel running, motorized treadmills, and swimming. Swimming is the most beneficial option due to its safe and controlled intensity levels. This protocol details the rat breeding methods, swimming training during pregnancy, and post-breeding nursing protocols. This model, suitable for various rat and mouse species, is useful for studying the benefits of maternal exercise on offspring health and intergenerational wellness.

Here, we present a protocol to delineate rat breeding methods, swimming training procedures, and post-breeding nursing protocols for pregnant rats after training. This protocol provides an animal model for studying the effects of maternal exercise during pregnancy on offspring and its underlying mechanisms.

The developmental origins of health and disease concept highlights the impact of early environments on chronic non-communicable diseases like diabetes, ...

Mating and Feeding Rats for Maternal Exercise Training to Study Offspring Health

To begin, label the microscope slides with the date and identification details of the rat. Between 6:00 and 7:00 p.m. grasp the base of the female rat's tail with the thumb and forefinger while applying pressure from the other fingers onto the lumbar vertebra of the rat.To collect vaginal secretions, moisten the cotton swab with saline solution. After lifting the rat tail, insert the tip of the swab gently into the vagina and roll it. Then, roll the swab tip across the slide.And locate the cells under the microscope using the 10X objective. After recording the estrus cycle stage, place the female rat along with a male rat in the mating cage between 7:00 to 8:00 p.m. On the second day between 7:00 and 8:00 a.m.if a copulatory plug is found at the base of the mating cage, examine the vaginal secretion smear of the female rat, as demonstrated earlier. If pregnancy is confirmed, isolate the female rat in a separate cage. On gestation day 20, replace the pregnant rat's cage with a clean one.And place medical absorbent cotton in the cage. Supply sufficient water and food for seven days. And position the cage in a quiet location.On the 21st day postpartum, distinguish the gender of the offspring rats. In females, the distance between the anus and the external genitalia is shorter than it is for males. Place the male and female offspring in two separate cages.

Prenatal Rat Swimming to Explore Offspring Health Benefits

To begin, obtain female rats for adaptation training. Then, grasp the tip of the rat's tail, lift it, and place the rat in a circular bucket filled with water. Throughout the 15 minute adaptation training, monitor the water temperature every five minutes, and add warm water to maintain the temperature.After the training, wash the rat fur in clean water, tempered at approximately 34 degrees Celsius, and transfer the rat to a cage with towels. Using a hand dryer, dry its fur thoroughly. Weigh the pregnant rat every day before training.For swimming training sessions, place the rat in water, taken in a circular bucket, and let it swim while maintaining the water temperature at about 34 degrees Celsius. Following the exercise, dry the rat, and provide it with five grams of rodent sunflower seeds as a nutritional supplement. Thoroughly clean and disinfect all equipment with ultraviolet light, including water buckets and towels.