Pups Of Dams Research Articles

Sex‐Specific Alterations on Muscle Plasticity and Myogenesis in Offspring Rats from Vitamin D Deficient Mothers

ObjectiveTo analyze the impact of maternal Vitamin D deficiency (VDD) on offspring muscle development in adulthood of male and female rats.MethodsTwelve 5‐week‐old female Wistar Hannover rats were fed either a Vit. D3+ diet (AIN93G with 1000 IU vitamin D3/kg diet) or Vit. D3− diet (AIN93G without vitamin D3) for six weeks and then bred to male rats. Mothers were maintained on the diets throughout gestation and lactation. At weaning, male and female offsprings were separated in four groups: male and female offspring control (M‐CTRL and F‐CTRL, respectively) pups of dams with Vit. D3+ diet; male and female offspring VDD (M‐VDD and F‐VDD, respectively) pups of dams with Vit. D3− diet. Offspring received a standard diet (Nuvilab) until 180 days of age, at which point tissues were harvested for analysis. *P≤0,05 (CEUA 052/2018).ResultsBoth male and female VDD groups showed a reduction in the calcidiol serum concentration (23±1 vs 40±2 ng/ml in M‐CTRL and 23±2.2 ng/ml vs 36.6±0.9 ng/ml in F‐CTRL) without affecting Ca+2 serum. At weaning, M‐VDD weighed less than M‐CTRL rats but recovered weight in the 60 days post weaning and acquired a greater body weight accompanied by a higher mass of white and brown adipose tissue at 180 days. Extensor digitorum longus (EDL) muscles from the M‐VDD showed a decrease (20 %; p<0.05) in the number of total fibers and an increase in the cross sectional area of IIB (17 %), IIA (19 %) and IIAX (21%; p<0.05) fibers. VDD also deregulated myogenesis as indicated by the higher levels of MyoD (43%; p<0.05) and Myogenin (160%; p<0.05) and in the number of satellite cells (128.8±14 vs 91±7.6 nuclei Pax7+ in the MO‐CTRL). To further investigate the signaling pathways involved in the muscle hypertrophy effect in the M‐VDD group, p‐IGF‐1/insulin receptor levels, and different insulin downstream targets related to protein synthesis including Ser 473p‐Akt, Ser 21/9 p‐GSK‐3β and Ser 209p‐eIF4e were measured. VDD increased all these parameters and in parallel increased plasma insulin and muscle IGF‐1 mRNA levels, but did not affect mTOR signaling. These changes were not found in Soleus from the M‐VDD group and in both EDL and Soleus from the female offspring.ConclusionMaternal VDD selectively affect the development of glycolytic muscle in male offspring characterized by hypoplasia, hypertrophy and deregulated myogenesis. The muscle hypertrophy is a compensatory mechanism probably due to the greater insulin sensitivity and activation of the Akt pathway. Muscles from female offspring seem to be protected from this metabolic disturbance showing a clear sex‐specific effect induced by maternal VDD.Support or Funding InformationFAPESP (19/06517‐1; 18/10089‐2)

A single immunization with inactivated H1N1 influenza vaccine formulated with delta inulin adjuvant (Advax™) overcomes pregnancy-associated immune suppression and enhances passive neonatal protection

Pregnant women and neonates represent high-risk groups for influenza infection, and in general have suppressed responses to standard influenza vaccines due to pregnancy-associated immune suppression and immune system immaturity, respectively. We therefore wished to test whether addition of Advax™, a polysaccharide adjuvant based on delta inulin, to an inactivated influenza vaccine (A/H1N1/PR8) administered during pregnancy would safely enhance vaccine immunogenicity and thereby provide improved protection of pregnant mothers and their newborns. Pregnant mice received a single intramuscular injection of β-propiolactone-inactivated H1N1 antigen alone or with Advax adjuvant. Pregnant dams receiving Advax-adjuvanted vaccine exhibited significantly increased serum and breast milk anti-influenza IgG titers. This translated into higher serum anti-influenza IgG titers in the pups of these dams. Complete protection was seen in pups of dams that received Advax-adjuvanted vaccine whereas no survival was seen in pups of control mothers or mothers immunized with unadjuvanted influenza vaccine. Cross-fostering studies confirmed that enhanced protection of pups of dams that received Advax-adjuvanted vaccine was mediated by enhanced transfer of maternal IgG to the pups via breast-feeding. The delta inulin adjuvant was not associated with any reproductive or developmental adverse effects. This study shows that Advax adjuvant was safe when administered with influenza vaccine during pregnancy and provided protection of pups via enhanced breast milk transfer of anti-influenza antibodies, not seen with administration of unadjuvanted vaccine.

授乳期間に食事制限をした母親の仔ラットは最適な成長を成し遂げるために大量の脂質を摂取する

授乳期間に食事制限をした母親の仔ラットは最適な成長を成し遂げるために大量の脂質を摂取する

The role of oxidative stress in renal injury induced in rats by losartan exposure during lactation

Rats exposed to angiotensin II (AII) receptor antagonists during lactation present progressive disturbances in renal development that lead to progressive alterations in renal function and structure. This study evaluates the role of oxidative stress in the renal changes induced by exposure to losartan, a type 1 AII receptor antagonist, in rats during lactation. Male Wistar pups were divided into: Control, pups of dams that received 2% sucrose solution; Control-tempol, pups of dams that received tempol (0.34 g/l), a superoxide dismutase mimetic compound; Losartan, pups of dams that received losartan (100 mg/kg/day), and Losartan-tempol, pups of dams that received losartan and tempol. Losartan and/or tempol were administered during lactation. Blood and urine samples were collected at 21 or 60 days, and the kidneys were removed. Losartan-treated pups exhibited disturbances in renal function and structure that persisted into adulthood. Tempol treatment reduced oxidative stress and attenuated the changes induced by losartan in the glomerular filtration rate, desmin expression at the glomerular edge, vimentin in tubular cells, as well as apoptosis and inflammatory infiltration in the renal cortex. Oxidative stress contributes at least in part to the renal injury observed in pups exposed to losartan during lactation.

Effects of diet and handling on initiation of independent ingestion in rats.

The present study examined the effects of dietary manipulation on the age of onset of weaning in rat pups. In Experiment 1, female rats were placed on a standard chow (SC) or high-fat (HF) diet 1 week following mating. Pups were weighed daily from birth to Day 12, then animals were placed into specialized cages for separate recording of food intake of pups and dams. Pups were offered the same diet as their dam, and food intake and body weight were determined twice daily until Day 25. The results demonstrated that pups reared by dams fed the HF diet initiated independent ingestion on Day 16, approximately 24 hr before pups reared by dams fed the SC diet. There were no differences in body weight in pups across the two diets. While few differences were noted across diets in pups' or dams' behavior, HF pups appeared to demonstrate a delay in the establishment of circadian patterns of food intake. In Experiment 2, all dams were maintained on an SC diet until the day after parturition. At that time, dams and litters were placed into specialized cages and divided into four groups: HF/HF, HF/SC, SC/SC, and SC/HF (dam's diet/pup's diet, respectively). The results demonstrated that dams given the HF diet had pups that initiated food intake approximately 2 days before the pups of dams given the SC diet. In addition, pups offered the HF diet, independent of the dam's diet, initiated food intake approximately 0.8 days prior to pups offered the SC diet. Further, by Day 12, HF dams had pups that were heavier than SC dams. The results suggest that the onset of weaning in rats is affected by maternal diet and the weaning diet available to the pup.

The Effects of <I>In Utero</I> and Lactational Exposure to Chloroform on Postnatal Growth and Glucose Tolerance in Male Wistar Rats

Water chlorination results in the formation of trihalomethanes (THMs) including chloroform. In human stud-ies, fetal growth restriction has been associated with exposure to THMs during pregnancy and impaired fetal growth has been associated with an increased risk of type 2 diabetes. Therefore, the objective of this study was to determine the effect of in utero and lactational exposure to chloroform on birthweight and postnatal indicators of type 2 diabetes. Female Wistar rats were given chloroform (0 microg/L, 75 microg/L) in their drinking water for 2 wk prior to mating until parturition (in utero exposure only) or until weaning (in utero+lactational exposure). At postnatal d 1 (PND1) pups of dams exposed to chloroform had significantly higher serum glucose levels and lower insulin levels, but this effect was not due to b<FONT "Optima">-cell depletion in the neonatal pancreas. Glucose homeostasis in response to a glucose challenge was not changed by chloroform treatment. Chloroform exposure did not affect birthweight; however, offspring of dams exposed to chloroform had significantly impaired postnatal growth. Although fetal and neonatal exposure to chloroform did not elicit physiological changes associated with the onset of type 2 diabetes, there were physiological changes resulting in impaired postnatal growth.

Lack of evidence for intergenerational reproductive effects due to prenatal and postnatal undernutrition in the female CD-1 mouse

The impacts of adverse environments during the prenatal and/or early postnatal periods may be manifested as functional deficits that occur later in life. Epidemiological studies have shown an association of sub-optimal pregnancy outcomes in one generation with similar events in the following one, a phenomenon termed the “intergenerational effect”. Data indicate that the incidence of adverse pregnancy outcomes and/or low birth weight infants is more closely correlated with the mother’s perinatal environment than with that during her pregnancy. However, epidemiological studies are inherently limited given the variability of lifestyles, ethnicity, nutritional status, and exposures to environmental factors. An appropriate animal model would permit control of parameters that may be impossible to evaluate in human populations. The current studies investigated the mouse as a possible animal model. Pregnant CD-1 mice were placed on an ad libitum or food-restricted diet (50% normal) throughout gestation to generate control (CON) and intrauterine growth retarded (IUGR) litters. At birth (postnatal day (PD) 1) pups (F1) were cross-fostered to control dams in litters of either 8 (CON) or 16 (postnatal food restriction (FR)). The experimental groups thus generated represented adequate nutrition (CON-CON) and undernutrition during the prenatal (IUGR-CON), or postnatal periods (CON-FR), or both (IUGR-FR). Pups of dams on a restricted diet during gestation had significant IUGR ( P<0.001) as compared to controls (birth weights of 1.32 g versus 1.63 g). At weaning, the average weight of the pups was dependent on postnatal litter size and the difference in birth weights between IUGR and CON animals was not a significant factor. CON-CON pup weight was 24.1 g and IUGR-CON was 22.2 g as compared to the CON-FR (17.0 g) and IUGR-FR (17.3 g) groups. The difference in weaning pup weights between the FR and CON groups was significant ( P<0.01). The F1 FR females did not reach CON female weights at any time point through 11 months after weaning. At PD60, a single breeding period for all groups of females with CON males began and continued for 75 days with 17 opportunities for breeding. Animals that became pregnant during this time were removed and allowed to litter. No significant differences were noted in average F2 litter size or average pup weight at birth: (CON-CON 12.2/1.62 g; IUGR-CON 11.9/1.62 g; CON-FR 10.9/1.70 g; IUGR-FR 11.3/1.61 g). We conclude that body weight at birth in the CD-1 mouse is not correlated with growth through the period of weaning (PD28). We did not find any evidence for an intergenerational reproductive effect after developmental undernutrition.

Nutritionally-Directed Compensatory Growth Enhances Mammary Development and Lactation Potential in Rats

A nutritionally-regulated compensatory growth regimen imposed during a growing period from prepuberty to gestation can significantly affect mammary development and subsequent lactation performance. The objectives of this study were as follows: 1) to determine whether a compensatory nutrition regimen enhances lactation potential for the first and second lactation cycles and 2) to determine the extent to which a compensatory nutrition regimen modulates cell proliferation, differentiation, and apoptosis and expression of genes in mammary tissues of female rats. Female Sprague-Dawley rats (n = 122, 35 d of age) were randomly assigned either to the control group, with free access to diet, or to a stair-step compensatory nutrition feeding regimen, with an alternating 2–2-3–3-wk schedule. The regimen began with an energy-restricted diet (40% restriction) for 2 wk, followed by the control diet for 2 wk; this step was then repeated at 3-wk intervals. Pups of dams from the compensatory nutrition regimen group gained more during mid-lactation than did control group pups. Mammary tissues were obtained from early (d 2) and late (d 19) lactating rats. Mammary tissue from the compensatory nutrition group exhibited increased cell proliferation and greater γ-glutamyltranspeptidase and ornithine decarboxylase gene expressions than did tissue from the control group during early lactation of both cycles. Mammary tissue from the compensatory nutrition group also had fewer apoptotic cells than tissue from the control group during late lactation of the first lactation cycle. These results suggest that the compensatory nutrition regimen imposed during the peripubertal developmental phase stimulated mammary growth and enhanced lactation performance by affecting the expression of genes that regulate the cell cycle.

Lactational Exposure and Neonatal Kinetics of Methylmercury and Inorganic Mercury in Mice

The concentration of mercury in milk and the distribution pattern in the sucking pup was followed over time after administration of a single iv injection of 0.5 mg/kg body wt of203Hg-labeled methylmercuric chloride or mercuric chloride to lactating mice on Day 10 of lactation. Mercury concentrations in milk of the dams and in whole body, blood, plasma, GI-tract, liver, kidneys, and brain of the offspring were followed up to 11 days after dosing (until lactational Day 21). Following the inorganic mercury dose to the dams, most of the mercury in milk was delivered to the pups during the first 24 h, but the maximum mercury concentration in plasma and tissues of pups was not reached until 7 days after dosing, indicating a prolonged absorption of inorganic mercury in the sucking pup. Pups of dams given methylmercury were exposed to a much lower and constant mercury concentration in milk. The estimated accumulated mercury dose via milk per pup of dams given methylmercury was less than half of that estimated after the inorganic mercury dose. When the accumulated dose via milk from methylmercury-exposed dams was compared to the amount of mercury in pup's carcass (whole body minus GI-tract including content), it was revealed that almost all mercury delivered via milk was absorbed, and that the suckling pups had a very low elimination of mercury until lactational Day 17. Lactational exposure following a maternal methylmercury or inorganic mercury dose resulted in almost similar mercury concentrations in liver, kidneys, and plasma of the suckling, but higher concentrations in brain (as most 14 times) and also twice as high mercury body burden in the methylmercury group. Thus, differences in kinetics indicate that lactational exposure of methylmercury is a greater hazard for the breast-fed infant than inorganic mercury.

Effects of maternal ethanol consumption on the subsequent development of immunity to Trichinella spiralis in rat neonates.

The immune response of rat pups to the intestinal parasite Trichinella spiralis was studied to determine if maternal pre- and/or postnatal ethanol consumption affected neonatal immune responses. Female rats were fed ethanol-containing (36% of calories) or pair-fed control liquid diets and include groups that were maintained on ethanol as follows: group 1, from day 1 of pregnancy through weaning and whose pups were then placed on ethanol to sacrifice; group 2, from day 1 of pregnancy through lactation; group 3, from day 1 of pregnancy through pup delivery; and group 4, from day 1 of lactation through weaning. A parallel group of animals was pair-fed isocaloric control diet until sacrifice. The pups of all litters were immunized orally with 500 L1 (T. spiralis) larva 5 days after weaning. To examine the effects of maternal ethanol on primary immune responses, one-fourth of the pups from each litter were sacrificed on days 10 and 20 after immunization. To examine the effects on neonatal secondary immune responses, the remaining pups were challenged with 1,000 larva 30 days after the initial immunization and sacrificed either 3 or 8 days after challenge. At the time of sacrifice, blood samples were collected, the intestine removed to determine T. spiralis worm burdens, and suspensions of mesenteric lymph node (MLN) cells prepared. Intestinal worm counts and serum levels of anti-T. spiralis IgM and IgG antibodies, interleukin-2 (IL-2), and tumor necrosis factor (TNF) were determined. In vitro proliferation responses of MLN cells to T. spiralis antigen and to the mitogen concanavalin A (Con A) were also examined. Pups from groups 1 to 3 demonstrated significantly higher intestinal worm counts (decreased immunity) than the pair-fed controls at the day 20 primary immune response sacrifice, and pups from group 1 had significantly higher worm counts at day 3 after a secondary immune challenge. Pups of dams from groups 1, 3, and 4 had significantly lower IgM antibody titers at the day 20 primary immune response sacrifice. All experimental ethanol groups (1 to 4) demonstrated significantly lower IgG antibody titers than that observed in pair-fed control pups at the 20-day sacrifice. IgM antibody titers showed significant reductions for ethanol-treated groups at 3 and 8 days after T. spiralis secondary challenge. In addition, IgG antibody titers were also significantly reduced for all alcohol groups at 3 and 8 days during the secondary immune response. Serum IL-2 and TNF levels were significantly lower in all experimental ethanol groups (1 to 4) relative to pair-fed controls at day 20 during a primary immune response, and IL-2 levels at 3 days postchallenge were lower in groups 2 to 4 after a secondary immune challenge. MLN proliferation responses to antigen and Con A were significantly reduced in ethanol groups 1 to 3 and to Con A in group 4 at day 10 after a primary immune challenge. Ethanol group 3 pups also demonstrated a reduced response to antigen at day 20. For animals undergoing a secondary immune response, ethanol group 2 demonstrated a reduced response to antigen at day 3, whereas groups 2 and 4 showed increased reactivity to antigen at days 3 and 8 postchallenge. These results show that maternal ethanol consumption diminishes the capacity of neonates to respond to T. spiralis antigen and that the depressed immune response involves T- and B-cell-mediated reactions and also affects the production of certain cytokines. These results also suggest that the diminished immune responses are increased with longer periods of maternal and neonatal exposure to ethanol.

Modulation of hepatic glutathione system of enzymes in suckling mouse pups exposed translactationally to malathion.

The present study examines the transmammary modulation of the glutathione system of enzymes in the F1 generation of mouse pups postnatally exposed to malathion. Lactating Swiss albino mice received either 30 or 100 mg malathion kg-1 body wt. (98% pure) for 14 or 21 days postpartum. The acid-soluble sulphydryl content was significantly increased (P < 0.001) in the liver of 14-day-old pups of dams that had received the higher malathion dose. A similar significant increase was seen in the 21-day-old male pups of dams that had received 30 mg (P < 0.05) or 100 mg (P < 0.01) malathion kg-1 body wt. Dams showed an enhanced hepatic glutathione S-transferase activity following treatment with 100 mg malathion kg-1 body wt. for 14 days (P < 0.02) and 21 days (P < 0.001). Pups of either age groups also showed enhanced hepatic glutathione S-transferase activity (P < 0.001). A significant enhancement in glutathione reductase activity was observed with malathion treatment in livers of dams and pups (P < 0.001). However, dams that had received 30 mg malathion kg-1 body wt. daily for 21 days or 100 mg malathion kg-1 body wt. for either 14 or 21 days showed significantly reduced hepatic glutathione peroxidase activity (P < 0.01, P < 0.001). A significant decrease in glutathione peroxidase activity was also observed in the liver of the 21-day-old male (P < 0.01) and female (P < 0.02) pups of dams that were treated with the higher dose of malathion.

The effects of maternal ethanol consumption on lactational transfer of immunity to Trichinella spiralis in rats.

Transient immunity to the intestinal parasite Trichinella spiralis can be transferred from the mother to the neonate during lactation. The goal of this study was to determine whether maternal ingestion of ethanol during pregnancy and lactation inhibited expression of anti- T. spiralis immunity in nursing pups. Groups of female rats were infected with 1000 T. spiralis L1 larva, mated, and fed either ethanol-containing or isocaloric liquid diets and maintained on diets through pregnancy and lactation or were fed the liquid diets for 30 days before T. spiralis infection, mated, and maintained on diets through pregnancy and lactation. Pups were challenged orally with 200 T. spiralis larva at 14 days postdelivery (preweaning period) or 21 days postdelivery (postweaning period) and were sacrificed either 3 or 8 days after respective challenge. Intestinal worm counts and serum titers of anti-T. spiralis IgG antibodies were determined for each pup. No difference in the number of intestinal worms between pups of ethanol-treated and pair-fed dams that received ethanol diet after T. spiralis infection was observed in the preweaning period. This was also true of pups from the dams sacrificed at 3 days after challenge in the postweaning period. However, similar pups sacrificed at 8 days after challenge showed significantly higher worm counts (decreased immunity) relative to their pair-fed controls. Pups of dams that received ethanol containing diet 30 days prior to T. spiralis-infection showed significantly higher numbers of intestinal worms relative to pair-fed pups at both the preweaning and postweaning periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Neonatal modulation of hepatic acid soluble sulfhydryls and xenobiotic metabolizing enzymes in suckling mice exposed translactationally to butylated hydroxyanisole.

The present study examines the effect of butylated hydroxyanisole (BHA) exposure through mother's milk on some of the hepatic xenobiotic metabolizing enzymes in the F1 offspring. Lactating Swiss albino mice received either a 0.5 or 1% BHA diet during the lactation period. The acid-soluble sulfhydryl content and activities of glutathione S-transferase and glutathione reductase increased significantly (p < 0.01) whereas the activity of glutathione peroxidase decreased significantly (p < 0.01) in the liver of pups exposed to BHA via milk. The hepatic content of cytochrome b5 increased (p < 0.01) while that of cytochrome P-450 decreased (p < 0.01) in the pups of dams which received a 1% BHA diet during lactation.

Pre- and Neonatal Exposure to a High Salt Diet and the Susceptibility to Hypertension in the Dahl Rat

The effects of a low or high salt diet (0.4% or 8.0% NaCI w/w) on pregnant or lactating inbred Dahl hypertension-sensitive (S/JR) and hypertension-resistant (R/JR) rats were examined. Offspring from these groups were weaned to a high or low salt diet and their susceptibility to salt-induced hypertension (HT) was investigated. Pregnancy attenuated the development of salt-induced HT in S/JR dams and reduced blood pressure (BP) in R/JR dams. In the S/JR strain, HT during pregnancy had little effect on infant mortality but did suppress the growth rate. Pre-weaning RP was greater in the S/JR offspring of dams maintained on a high salt diet during pregnancy. At maturity, rats in this group displayed a significantly greater degree of cardiac hypertrophy than rats prenatally exposed to a low salt diet. S/JR pups of dams maintained on a high salt diet while nursing also displayed a greater than normal increase in BP during the pre-weaning period, Prenatal exposure of the S/JR strain to a high salt diet also facili...

Postnatal development of the bronchiolar Clara cell in rats.

We studied aspects of perinatal rat bronchiolar Clara cell development. We found that the volume density (Vv) of glycogen areas decreased 10-fold between postnatal days 1 and 2 and that the Vv of secretory granules, rough endoplasmic reticulum (RER), and mitochondria increased markedly during the 1st postnatal wk. Compared with pups of dams allowed food ad libitum during gestation, pups from dams underfed during gestation had a higher Vv of glycogen areas for the first 2 postnatal days but a lower Vv of secretory granules and RER for the time studied (to age 7 days). Glucagon injected, in utero, into fetal rats at 21.5 days of gestation resulted in a 40% decrease in the Vv of the glycogen areas within 4 h. We conclude that 1) bronchiolar Clara cells are immature at birth and undergo marked early postnatal maturation, 2) prenatal events (maternal undernutrition) affect postnatal maturation of the Clara cells, and 3) exogenous glucagon leads to glycogen depletion in Clara cells of fetal rats of 21.5 days gestation.