Effect of chronic protein-energy malnutrition on fecundability, fecundity and fertility in rats

Kallikrein-kinin system and oxidative stress in cisplatin-induced ovarian toxicity

Kallikrein-kinin system (KKS) is involved in vascular reactivity and inflammatory response to cytotoxic drugs. Since cisplatin is a widely used chemotherapy and its cytotoxic mechanism can trigger inflammation and oxidative damage, in this work we evaluated the role of KKS in an animal model of cisplatin-induced ovarian toxicity. Biomarkers of ovarian stem cells, activity of KKS, inflammation and oxidative damage were measured in ovarian tissue of C57BL/6 female mice treated with vehicle or cisplatin (2.5 mg/kg). Cisplatin group presented greater number of atretic follicles, and lower numbers of antral and total viable follicles. Ki67, DDX4 and OCT-4 markers were similar between groups. Cisplatin triggered plasma and ovarian tissue kallikrein generation; and increased expression of bradykinin receptors B1 and B2. Neutrophil and macrophage infiltration markers increased. Superoxide anion generation also increased, while reduced glutathione levels decreased. These results suggest that KKS is activated and contributes to ovarian injury during cisplatin treatment.

Does ischemia reperfusion affect fecundability in a rat model?

BACKGROUND

Adnexal torsion constitutes 2.7% of all gynecological emergencies. Because normal follicular growth has been demonstrated after examination of surgical specimens retrieved from oophorectomies, organ-sparing strategy has gained more popularity irrespective of the appearance of the ovary. However, the functionality of the remaining follicles has not been known. The aim of the study was to evaluate the effect of ischemia-reperfusion on fecundability in a rat model with adnexal torsion.

METHODS

A total of 30 female adult Wistar albino rats were assessed. In the first laparotomy, right ovaries were twisted for 8 (Group I, n = 10) or 24 (Group II, n = 10) hours. Second laparotomy was performed to untwist the torsion side and oophorectomy to the other side. In the control group (Group III, n = 10), left ovaries were removed and right ovaries were kept without any intervention. After 30 days from the last operation, female rats were mated for 10 days and euthanized 4 days later. Fecundability was calculated using beta-human chorionic gonadotropin (hCG) levels for detection of pregnancy rates.

RESULTS

The mean beta-hCG values in control, 8-hour, and 24-hour groups between pregnant rats were 19.8 ± 26.02, 11.7 ± 0.17, and 22.97 ± 11.87 mIU/mL, respectively. Whereas two out of 10 rats (20%) conceived in the 8-hour group, three out of 10 rats (30%) got pregnant in the 24-hour group. In total, whereas five out of the 20 rats got pregnant in the experimental groups, in the control group, seven out of 10 subjects conceived (25% vs 70 %, p = 0.018).

CONCLUSION

Although there was a statistical difference between experimental and control groups, statistical significance was not reached among 8-hour and 24-hour torsion subgroups. In this context, patients with torsion but treated with detorsion should be further investigated for their fecundability potency and be informed accordingly.

Hypercaloric diet prevents sexual impairment induced by maternal food restriction

Prenatal undernutrition impairs copulatory behavior and increases the tendency to become obese/overweight, which also reduces sexual behavior. Re-feeding rats prenatally undernourished with a normocaloric diet can restore their physiological conditions and copulatory behavior. Thus, the present study investigated whether a hypercaloric diet that is administered in rats during the juvenile period prevents sexual impairments that are caused by maternal food restriction and the tendency to become overweight/obese. Female rats were prenatally fed a 40% restricted diet from gestational day 2 to 18. The pups received a hypercaloric diet from postnatal day (PND) 23 to PND65 (food restricted hypercaloric [FRH] group) or laboratory chow (food restricted control [FRC] group). Pups from non-food-restricted dams received laboratory chow during the entire experiment (non-food-restricted [NFR] group). During the juvenile period and adulthood, body weight gain was evaluated weekly. The day of balanopreputial separation, sexual behavior, sexual organ weight, hypodermal adiposity, striatal dopamine and serotonin, serum testosterone, and tumor necrosis factor α (TNF-α) were evaluated. The FRH group exhibited an increase in body weight on PND58 and PND65. The FRC group exhibited an increase in the latency to the first mount and intromission and an increase in serum TNF-α levels but a reduction of dopaminergic activity. The hypercaloric diet reversed all of these effects but increased adiposity. We concluded that the hypercaloric diet administered during the juvenile period attenuated reproductive impairments that were induced by maternal food restriction through increases in the energy expenditure but not the tendency to become overweight/obese.

Early protein malnutrition negatively impacts physical growth and neurological reflexes and evokes anxiety and depressive-like behaviors

Malnutrition is a worldwide problem affecting millions of unborn and young children during the most vulnerable stages of their development. In humans, poor maternal nutrition is a major cause of intrauterine growth restriction which is associated with an increased risk of perinatal mortality and long-term morbidity. In addition, intrauterine growth restriction correlates with neurodevelopmental delays and alterations of brain structure and neurochemistry. While there is no doubt that maternal malnutrition is a principal cause of perturbed development of the fetal brain and that all nutrients have certain influence on brain maturation, proteins appear to be the most critical for the development of neurological functions. In the present study we assessed male and female mouse offspring, born to dams protein restricted during pregnancy and lactation, in physical growth and neurobehavioral development and also in social interaction, motivation, anxiety and depressive behaviors. Moreover, we evaluate the impact of the low protein diet on dams in relation to their maternal care and anxiety-related behavior given that these clearly affect pups development. We observed that maternal protein restriction during pregnancy and lactation delayed the physical growth and neurodevelopment of the offspring in a sex-independent manner. In addition, maternal undernutrition negatively affected offspring's juvenile social play, motivation, exploratory activity and risk assessment behaviors. These findings show that protein restriction during critical periods of development detrimentally program progeny behavior.

Effect of increased dietary salinity on the reproductive status and energy intake of xeric and mesic populations of the spiny mouse, Acomys

The possible role of increased dietary salinity as a proximate regulator of reproduction in xeric population of golden spiny mice (Acomys russatus) and mesic population of common spiny mice (A. cahirinus) was tested. In the wild, as the dry season progresses, evaporative water loss in the vegetation increases. This leads to increase in particle concentration of plant tissues. Thus, species consuming a plant diet are exposed to increased dietary salinity. Both male and female individuals of A. russatus were subjected to gradually increasing dietary salinity (0.9%, 2.5%, 3.5%, and 5%) while those of A. cahirinus only up to 3.5% for a total period of 8 and 6 weeks, respectively. Urine osmolarity showed a significant increase under 3.5% and 5% salinity in A. russatus and 2.5% and 3.5% in A. cahirinus. Testis mass and spermatogenesis were significantly reduced while uterine mass and vaginal estrus cycles were not affected in A. russatus. None of the parameters was significantly affected in A. cahirinus. Increase in salinity also significantly reduced body mass in A. russatus but not in A. cahirinus. Mass-specific daily digestible energy intake was not significantly affected by increased salinity in both species. Recovery individuals regained body mass quickly and surpassed initial values after four weeks. However, testis mass and spermatogenesis did not show recovery. The results suggest that increase in dietary salinity could be used as a proximate signal to regulate reproduction in A. russatus by halting it in males, as the dry season progresses while such role in the mesic population of A. cahirinus is unlikely.

Two low protein diets differentially affect food consumption and reproductive performance in pregnant and lactating rats and long-term growth in their offspring

We fed 2 low protein diets (LPD) to rats during pregnancy and lactation, and compared food intake and reproductive performance in the dams, and long-term growth in their offspring. The L93 and LM76 LPDs were derived from the American Society of Nutrition's recommended AIN93G and a modified version of the AIN76A purified control diets, respectively. The LPDs contained 8% crude protein in the form of casein and differed in their fat and carbohydrate sources. The purified control diets contained 19% crude protein. A regular cereal-based diet was also included, therefore, a total of 5 groups were tested. Blood urea nitrogen concentrations in dams of both LPD groups were lower than their respective controls, confirming decreased protein intake. The LM76 diet lowered food consumption of dams and produced energy malnourishment during pregnancy that persisted throughout lactation. In contrast, the L93 diet produced energy malnourishment only during lactation. Offspring of both LPD groups exhibited lower birth weights than their respective controls. Despite initiating nutritional rehabilitation at weaning (d 28), perinatal administration of both low protein diets produced long-term reductions in the body weight of male offspring. Interestingly, in the female offspring, the LM76 diet reduced birth weight for the entire duration of the study (180 d), whereas the L93 diet produced a relatively short-term (up to 58 d) reduction in body weight. This suggests that the imprinting effect of the perinatal nutritional environment on body weight is diet and gender dependent. The performance of the purified control diet groups were similar to the nonpurified diet group in most measured biochemical indices, with the notable exception of a decrease in the body-weight normalized kidney weight of the dams.

Effects of soybean fortification on protein quality of tortilla-based diets produced from regular and quality protein maize

The physiological development of laboratory rats fed with a typical indigenous tortilla diet was studied for two generations. The experiment compared casein control diet and five different types of diets: (1) a diet of tortillas obtained from fresh masa (FM); (2) regular tortillas produced from enriched dry masa flour containing vitamins B1, B2, niacin, folic acid, and the microminerals iron and zinc (REDMF); (3) tortillas produced from enriched dry masa flour fortified with 6% defatted soybean meal (FEDMF); (4) tortillas produced from enriched quality protein maize flour (EQPM); and (5) and, tortillas produced from enriched quality protein maize flour fortified with 3% defatted soybean meal (FEQPM). The growth of rats fed FEDMF and FEQPM diets was significantly higher (P < 0.05) in both generations than their counterparts fed EQPM, REDMF, or FM diet. Animals fed quality protein maize (QPM) tortilla had the highest protein digestibility, but the FEQPM and FEDMF diets had the highest biological value (BV), net protein utilization (NPU), and protein-digestibility-corrected EAA scores (PDCEAAS). The difference among treatments was more evident in the second-generation rats. The pregnancy rate, number of newborns/litter, litter weight, and newborn survival rate was also higher for rats fed FEDMF, EQPM, and FEQPM diets than their counterparts fed REDMF and FM.

Effects of under- and overnutrition on lactation in laboratory rats

To study the effects of maternal nutritional status on lactational performance, the diets of laboratory rats were manipulated with food restriction or increases in fat concentration. Compared with rats fed control diets ad libitum, conception rate, milk production and litter growth decreased and milk fat concentration increased in both chronically food restricted and obese animals. Chronically food restricted rats mobilized body fat and reduced their energy expenditure for maintenance and activity. Differences in suckling pattern between control and food-restricted rats affected hormone concentrations important for successful lactation. Obese rats experienced greater difficulty than controls in delivering their pups and more of their pups died in the first days of life. Milk production among obese rats may be constrained by poor appetite and the high heat production that characterizes lactation in litter-bearing species. There are many parallels as well as important differences between results obtained from these models and findings in nursing women. Nevertheless, these models provide useful information about the possible mechanisms by which maternal nutritional status affects lactational performance.

Female reproductive profile in a fertile, genetically obese line of rats

The female reproductive profile of a fertile genetically obese line of rats, named beta, is characterized. Hypophysis, ovaries, oviducts, and uteri weights do not differ from those of nonobese controls. Histological features in ovary, uterus, and vagina in beta line and alpha controls are similar, in agreement with classical descriptions in the subject. Vaginal opening, number of estrus, number of corpora lutea at ovulation time, and pregnancy patterns (i.e., ovary weight, number of corpora lutea, sites of implantation, and living fetuses, as well as productivity, fertility, litter size, and preweaning mortality) show no significant differences between obese and nonobese animals. From a reproductive standpoint, obese beta line would behave as nonobese. Up to now beta would represent the only fertile genetically obese line of rats, appearing as a profitable biological model to widen and deepen reproductive analysis on obesity.