Nanochitosan Effect on Biomolecular, Hypolipidemic in Rats and Incorporation in Functional Yogurt.

<b>Background and Objective:</b> Chitosan has many functional properties and biological activities. This work aimed to prepare and characterize Chitosan Nanoparticles (CN). Then, evaluate the hypolipidemic and antioxidant effect of CN in rats. Incorporate CN in camel yogurt and evaluation of yogurt properties. <b>Materials and Methods:</b> Chitosan Nanoparticles (CN) were prepared and analyzed for the size, zeta potential and poly Polydispersity Index (PDI). Total 24 rats were divided into 4 groups, the negative control group was fed on the basal diet and the positive control group was fed on a High-Fat Diet (HFD), the group I and II were fed on the HFD+(CC) or (CN). The feeding period was 6 weeks. Prepared and Characterization stirred camel yogurt fortified by CN. <b>Results:</b> CN the size was 27.20 nm, ζ-potential+38.78. After the feeding period for CN and CC groups were a decrease in body weight, serum lipid profile and liver function in both tested groups and an increase in HDL-cholesterol and an increase in antioxidants in the CN group more than that in the CC group was observed. mRNA expression with qPCR for hepatic PPARγ, HL, GSS and CYP2E1 genes was performed to investigate the alterations in their levels after CN treatment on the liver of rats fed with HFD. <b>Conclusion:</b> CN possesses the ability to improve the impairment of lipid metabolism as strongly associated with gene expressions related to lipogenesis and oxidative stress. Also, the addition of 2% CN to camel yogurt gave sensory acceptable and microbiological quality.

Simulated gastric hydrolysis and developmental toxicity of dibutyltin bis(2-ethylhexyl thioglycolate) in rats.

Previously, dibutyltin dichloride (DBTC) was the putative toxophore for dibutyltin bis-alkyl and bis-thio esters. Recent chemical and toxicological data on dioctyltin bis(2-ethylhexyl thioglycolate) suggest the thioglycolate esters of alkyltins do not generate the dichloride toxophore. Our results, using 119 Sn-nuclear magnetic resonance (NMR) spectroscopy, demonstrated that dibutyltin bis(2-ethylhexyl thioglycolate) (DBTE) is hydrolyzed to dibutyltin chloro-(2-ethylhexyl thioglycolate) (DBTEC) under simulated gastric conditions. No DBTC was detected. DBTE was administered orally to presumed-pregnant Sprague-Dawley rats in a corn oil vehicle at 2.5, 8.5, and 25.0 mg/kg/day (Gestation Day 5 [GD5] through GD19). There were no maternal deaths, no treatment-related statistically significant reductions in feed consumption, maternal body weight or weight gain, or adverse gestational outcomes. Maternal thymus weight was significantly reduced in rats at 25 mg/kg. There were no effects on fetal growth, no dose-dependent pattern of external, visceral, or skeletal malformations, and no increase in anatomical variations. Based on the obtained experimental data, it is concluded here that DBTE forms DBTEC, not DBTC, in the stomach, and DBTE was not teratogenic nor fetotoxic in rats, a species sensitive to DBTC. The maternal no-observed-adverse-effect level (NOAEL) was 8.5 mg/kg/day, and the developmental NOAEL was 25 mg/kg/day, the high dose. The maternal LOAEL was 25 mg/kg/day based on reduced maternal thymus weight.

Chronic developmental lead exposure increases µ-opiate receptor levels in the adolescent rat brain.

Childhood lead (Pb2+) intoxication is a global public health problem best known for producing deficits in learning and poor school performance. Human and preclinical studies have suggested an association between childhood Pb2+ intoxication and proclivity to substance abuse and delinquent behavior. While environmental factors have been implicated in opioid addiction, less is known about the role of exposure to environmental pollutants on the brain opioid system. Opioid receptors are involved in the biological effects of opioids and other drugs of abuse. In this study, we examine the effect of chronic developmental Pb2+ exposure (1500 ppm in the diet) on µ-opioid receptor (MOR) levels in the rat brain using [3H]-d-Ala2-MePhe4-Gly-ol5 enkephalin ([3H]-DAMGO) quantitative receptor autoradiography at different developmental stages (juvenile, early-adolescent, late adolescent and adult) in male and female rats. Our results indicate that chronic developmental Pb2+ exposure increases the levels of [3H]-DAMGO specific binding to MOR in juvenile and early adolescent Pb2+-exposed male and female rat brain with no changes in late-adolescent (PN50) and minor changes in Pb2+-exposed adult male rats (PN120). Specifically, at PN14, Pb2+-exposed males had an increase in MOR binding in the lateral posthalamic nuclei (LPTN), and Pb2+-exposed females had increased MOR binding in LPTN, medial thalamus, and hypothalamus. At PN28, Pb2+-exposed males had increased MOR levels in the striatum, stria medullaris of the thalamus, LPTN, medial thalamus, and basolateral amygdala, while Pb2+-exposed females showed an increase in nucleus accumbens core, LPTN, and medial thalamus. No changes were detected in any brain region of male and female rats at PN50, and at PN120 there was a decrease in MOR binding of Pb2+-exposed males in the medial thalamus. Our findings demonstrate age and gender specific effects of MOR levels in the rat brain as a result of chronic developmental Pb2+ exposure. These results indicate that the major changes in brain MOR levels were during pre-adolescence and early adolescence, a developmental period in which there is higher engagement in reward and drug-seeking behaviors in humans. In summary, we show that chronic exposure to Pb2+, an ubiquitous and well-known environmental contaminant and neurotoxicant, alters MOR levels in brain regions associated with addiction circuits in the adolescent period, these findings have important implications for opioid drug use and abuse.

Cholinergic- rather than adrenergic-induced sweating play a role in developing and developed rat eccrine sweat glands.

Both cholinergic and adrenergic stimulation can induce sweat secretion in human eccrine sweat glands, but whether cholinergic and adrenergic stimulation play same roles in rat eccrine sweat glands is still controversial. To explore the innervations, and adrenergic- and cholinergic-induced secretory response in developing and developed rat eccrine sweat glands, rat hind footpads from embryonic day (E) 15.5-20.5, postanal day (P) 1-14, P21 and adult were fixed, embedded, sectioned and subjected to immunofluorescence staining for general fiber marker protein gene product 9.5 (PGP 9.5), adrenergic fiber marker tyrosine hydroxylase (TH) and cholinergic fiber marker vasoactive intestinal peptide (VIP), and cholinergic- and adrenergic-induced sweat secretion was detected at P1-P21 and adult rats by starch-iodine test. The results showed that eccrine sweat gland placodes of SD rats were first appeared at E19.5, and the expression of PGP 9.5 was detected surrounding the sweat gland placodes at E19.5, TH at P7, and VIP at P11. Pilocarpine-induced sweat secretion was first detected at P16 in hind footpads by starch-iodine test. There was no measurable sweating when stimulated by alpha- or beta-adrenergic agonists at all the examined time points. We conclude that rat eccrine sweat glands, just as human eccrine sweat glands, co-express adrenergic and cholinergic fibers, but different from human eccrine sweat glands, cholinergic- rather than adrenergic-induced sweating plays a role in the developing and developed rat eccrine sweat glands.

Variation in lysine, threonine, and tryptophan availability in meat and bone meal as estimated by the slope-ratio growth assay technique in growing rats.

Meat and bone meal (MBM) is an important protein source used in animal feeds. However, as the composition and availability of amino acids (AAs) in MBM fluctuate markedly, it is important to verify the magnitude of these parameters in different MBMs. In this study, the AA compositions of 19 MBMs were analyzed to confirm variations in lysine (Lys), threonine (Thr), and tryptophan (Trp), then which were compared with those of soybean meal (SBM) and fish meal (FM). Instability in Lys, Thr, and Trp availabilities in six MBMs were also considered after estimation using the slope-ratio growth assay technique in rats. Variations in AA composition were evaluated using the coefficient of variance (CV: Standard deviation/Mean). CVs for Lys, Thr, and Trp content were 9.40, 11.83, and 18.12 in MBM, 2.71, 2.48, and 3.19 in SBM, and 10.09, 10.44, and 13.47 in FM. Furthermore, means and SDs for Lys, Thr, and Trp availabilities in MBM were 53.3 ± 10.4% (CV: 19.5), 65.9 ± 17.6% (CV: 26.6), and 83.2 ± 11.2% (CV: 13.5), respectively. These results provide the first evidence that variations in MBM AA compositions were 3.5 to 5.7 times higher than those in SBM, but similar to FM, and that the large variation in availability substantially existed.

Disruption of insulin receptor substrate-2 impairs growth but not insulin function in rats.

Insulin receptor substrate (IRS)-2, along with IRS-1, is a key signaling molecule that mediates the action of insulin and insulin-like growth factor (IGF)-I. The activated insulin and IGF-I receptors phosphorylate IRSs on tyrosine residues, leading to the activation of downstream signaling pathways and the induction of various physiological functions of insulin and IGF-I. Studies using IRS-2 knockout (KO) mice showed that the deletion of IRS-2 causes type 2 diabetes due to peripheral insulin resistance and impaired ß-cell function. However, little is known about the roles of IRS-2 in other animal models. Here, we created IRS-2 KO rats to elucidate the physiological functions of IRS-2 in rats. The body weights of IRS-2 KO rats at birth were lower compared with those of their WT littermates. The postnatal growth of both male and female IRS-2 KO rats was also suppressed. Compared with male WT rats, the glucose and insulin tolerance of male IRS-2 KO rats were slightly enhanced, whereas a similar difference was not observed between female WT and IRS-2 KO rats. Besides the modestly increased insulin sensitivity, male IRS-2 KO rats displayed the enhanced insulin-induced activation of the mTOR complex 1 pathway in the liver compared with WT rats. Taken together, these results indicate that in rats, IRS-2 plays important roles in the regulation of growth but is not essential for the glucose-lowering effects of insulin.

Effects of extruded whole-grain sorghum (Sorghum bicolor (L.) Moench) based diets on calcium absorption and bone health of growing Wistar rats.

Apparent calcium absorption, total bone mineral content and density, and mineral contents of the right femur were studied using a growing rat model. Twenty-four male Wistar rats were fed with diets based on extruded whole grain red (RSD) or white sorghum (WSD), and control diet (CD) up to 60 days. The animals fed with sorghum diets consumed less and gained less weight compared to those fed with CD, but the efficiency of all diets was similar. Calcium intake was lower in animals fed with sorghum diets, related to the lower total intake of these animals. Apparent calcium absorption in animals fed with RSD was lower than in those fed with CD (CD: 72.7%, RSD: 51.0%, WSD: 64.8%). No significant differences in bone mineral density of total body, spin, femur, distal femur, tibia and proximal tibia were observed among the groups. However, Ca and P contents in the right femur of the rats consuming RSD were lower, indicating a certain imbalance in the metabolism of these minerals.

Transitional Hybrid Skeletal Muscle Fibers in Rat Soleus Development.

Skeletal muscles comprise hundreds of individual muscle fibers, with each possessing specialized contractile properties. Skeletal muscles are recognized as being highly plastic, meaning that the physiological properties of single muscle fibers can change with appropriate use. During fiber type transitions, one myosin heavy chain isoform is exchanged for another and over time the fundamental nature of the fiber adapts to become a different fiber type. Within the rat triceps surae complex, the soleus muscle starts out as a muscle comprised of a mixture type IIA and type I fibers. As neonatal rats grow and mature, the soleus undergoes a near complete transition into a muscle with close to 100% type I fibers at maturity. We used immunohistochemistry and single fiber SDS-PAGE to track the transformation of type IIA into type I fibers. We found that transitioning fibers progressively incorporate new myofibrils containing type I myosin into existing type IIA fibers. During this exchange, distinct type I-containing myofibrils are segregated among IIA myofibrils. The individual myofibrils within existing muscle fibers thus appear to represent the functional unit that is exchanged during fiber type transitions that occur as part of normal muscle development.

Evaluation of copper metabolism in neonatal rats by speciation analysis using liquid chromatography hyphenated to ICP mass spectrometry.

It is known that copper (Cu) is highly accumulated in several organs in the perinatal period, suggesting changes in Cu metabolism with development, although the precise mechanisms are still unclear. To elucidate the mechanisms underlying Cu accumulation in the organs of neonatal rats, we performed speciation analysis using high-performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry. In the neonatal rat liver immediately after birth, the Cu concentration was elevated 10-fold compared to that in the juvenile rat liver. Most of the accumulated Cu was bound to metallothionein, although Cu in Cu, zinc-superoxide dismutase (SOD) was reduced. Contrary to the hepatic Cu accumulation, the serum Cu concentrations in the neonatal rats were low due to the decreased amount of Cu bound to ceruloplasmin. The mRNA expression of antioxidant protein 1 (Atox1), a Cu chaperone that transports Cu to Atp7b, remained low up to two weeks after birth. These results suggest that Cu accumulation in the neonatal rat liver is caused by the low expression of Atox1, and the accumulation is useful to distribute Cu to Cu-containing anti-oxidative enzymes (e.g., SOD and Atox1) after respiration starts.

A preliminary study of fonio-moringa seed meal-based complementary food in Wistar rats.

Effect of fonio-moringa seed meal (FMSM)-based complementary food in Wistar rats was assessed in a 28 days balanced study. Seventy, 21-day-old Wistar rats were allotted to seven groups in a completely randomized design. Infant weaning foods (IWFs) 1, 2, 3, 4, and 5 had 0%, 5%, 10%, 15%, and 20% FMSM inclusion levels, respectively, while two commercial IWFs purchased were coded CFT and CFC. The water absorption capacity, swelling power, and the pasting properties, except peak time varied (p < .05) among the IWFs. Rats fed on IWFs 3 and 4 had comparable weight gain with those fed on the commercial foods. The heart and kidney relative weights were influenced (p < .05), while villus length (duodenum) of the rats were significant (p < .05). The blood indices were not significant, but the alanine aminotransferase and cholesterol levels ranged 15.65-32.25 µ/dl and 75.75-94.55 mg/100 ml, respectively. Incorporation of 10% FMSM is recommended in IWFs. PRACTICAL APPLICATIONS: The need to reduce hunger and starvation among the less-privileged people in society is becoming increasingly important. Specifically, many infants, preschool and school children are often not having access to nutritive foods that will enhance their mental alertness. The commercial IWFs on sale in Nigeria are in most cases high in prices and consequently out of the reach of the populace. Fonio is a starchy grain with an important potential not only as a survival food but as a compliment for standard diets. Also, moringa seed is known to be of nutritional value. Most infant formulae are based on maize and soybean and it is hoped that the incorporation of FMSM in the infant weaning formula will help to increase the nutritive value and stem the cost of IWFs.

Nutritional performance and antioxidant activities of roasted and unroasted sprouted sorghum-based weaning diets in Wistar rats.

The nutritional performance and antioxidant profile of sprouted sorghum-based weaning diets were evaluated in weaning wistar rats. Rats were fed basal diet, unroasted germinated sorghum-based diet, roasted germinated sorghum-based diet, or a commercial weaning feed (nutrend) for 28 days. Energy, carbohydrate, crude protein, lipids, crude fiber, and ash contents of the sorghum-based diets compared significantly with FAO/WHO recommendations. Contrastingly, moisture content of the germinated sorghum-based diet was higher than the recommendation. Weight gain, feed efficiency ratio, protein efficiency ratio, net protein utilization, biological value, and digestibility of unroasted germinated sorghum-based diet-fed rats compared significantly with Nutrend. Roasted germinated sorghum-based diet produced differential effects on these indices. The unroasted germinated sorghum-based diet significantly raised the antioxidant enzymes in the rat liver and kidney. Overall, evidence from the study indicates that unroasted germinated sorghum-based diet improves the nutritional performance and the antioxidants of weaning rats compared to the roasted germinated sorghum-based diet. PRACTICAL APPLICATIONS: The provision of nutritionally adequate food from local sources during the weaning period of infants continues to be a major source of concern in developing countries. The formulated unroasted sprouted sorghum-based diet can be adapted and used as weaning food. Furthermore, the diet can be processed and developed into a weaning food.

Impacts of Subchronic, High-Level Noise Exposure on Sleep and Metabolic Parameters: A Juvenile Rodent Model.

BACKGROUND: Noise is an environmental factor that has been associated with metabolic and sleep disorders. Sleep is a vital function, since it underpins physiologic processes and cognitive recovery and development. However, the effects of chronic noise exposure on the developing organism are still subject to debate. OBJECTIVE: The objective of the present study was to assess the effects of subchronic, high-level noise exposure on sleep, apnea, and homeostasis in juvenile rats. METHODS: Twenty-four 3-wk-old male Wistar rats were exposed to noise [[Formula: see text], [Formula: see text]] for 5 wk and 2 d during the 12-h rest period. Data on sleep stages, food and water intake, apnea, and body and organ weight were recorded. RESULTS: Five weeks of high-level noise exposure were associated with hyperphagia ([Formula: see text]), body weight gain ([Formula: see text]), a heavier thymus ([Formula: see text]), and heavier adrenal glands ([Formula: see text]). A sleep analysis highlighted microstructural differences in the active period: in particular, the mean daily amount of rapid eye movement (REM) sleep as a proportion of total sleep time (TST) was higher. The mean daily amount of non-REM (NREM) sleep was lower in the exposed group, meaning that the intergroup difference in the TST was not significant. During a 1-h, noise-free plethysmographic recording during the rest period, the mean total amount of active wakefulness (AW) was lower in the exposed group (by 9.1 min), whereas the mean duration of an episode of REM sleep was higher (by 1.8 min), and the TST was higher (by 10.7 min). DISCUSSION: Subchronic exposure of juvenile rats to high-intensity noise during the rest period was associated with some small but significant sleep disturbances, greater food and water intakes, greater body weight gain, and greater thymus and adrenal gland weights. The main effects of noise exposure on sleep were also observed in the 1-h plethysmography session after 5 wk of exposure. https://doi.org/10.1289/EHP4045.

Effects of exposure to ethanolic extract from Achyrocline satureioides (Lam.) D.C. flowers on reproductive and developmental parameters in Wistar rats.

Achyrocline satureioides (LAM) D.C. is a species plant used in folk medicine with several medicinal properties; however, few studies have focused on its potential adverse effects. The aim of this study was to examine the effects of ethanolic extract of A. satureioides flowers administered during pre-mating, mating, pregnancy and postpartum period on reproductive and developmental parameters in rats. Male and female rats received by gavage 0, 250, 500 or 750 mg/kg of extract. The animals were treated from pre-mating until 13 days post-partum. Phytochemical analysis revealed the presence of important flavonoids (quercetin, luteolin, caffeic acid, rutin, and ferulic acid). In females, biochemical, hematological or gestational parameters were not markedly altered by the extract. However, an increase in calcium and thyroid stimulating hormone (TSH) levels was found in treated-dams. Although TSH and T4 levels were not significantly altered in pups, there was a rise in body weight of pups whose mothers were treated with the extract. All males treated were able to successfully copulate with treated-females. However, rats exposed to 500 and 750 mg/kg of extract exhibited a significant decrease in daily testicular sperm production and delay in sperm transit time in the epididymis. The ethanolic extract of A. satureioides flowers produced adverse effects in the male reproductive system as evidenced by diminished sperm production and transport. In addition, the extract elevated TSH levels of exposed mothers which may consequently affect the development of pups but this requires further evaluation.

l-Methionine activates Nrf2-ARE pathway to induce endogenous antioxidant activity for depressing ROS-derived oxidative stress in growing rats.

BACKGROUND: Methionine is an essential sulfur-containing amino acid. To elucidate the influence of l-methionine on activation of the nuclear factor erythroid 2-related factor 2-antioxidant responsive element (Nrf2-ARE) antioxidant pathway to stimulate the endogenous antioxidant activity for depressing reactive oxygen species (ROS)-derived oxidative stress, male Wistar rats were orally administered l-methionine daily for 14 days. RESULTS: With the intake of l-methionine, Nrf2 was activated by l-methionine through depressing Keap1 and Cul3, resulting in upregulation of ARE-driven antioxidant expression (glutamate cysteine ligase catalytic subunit, glutamate cysteine ligase modulatory subunit, glutathione synthase (GS), catalase (CAT), superoxide dismutase (SOD), heme oxygenase 1, NAD(P)H:quinone oxidoreductase 1, glutathione reductase (GR), glutathione S-transferase (GST), glutathione peroxidase (GPx)) with increasing l-methionine availability. Upon activation of Nrf2, glutathione synthesis was increased through upregulated expression of methionine adenosyltransferase, S-adenosylhomocysteine hydrolase, cystathionine ß-synthase, cystathionine γ-lyse, glutamate cysteine ligase (GCL) and GS, while hepatic expressions of methionine sulfoxide reductases (MsrA, MsrB2, MsrB3) and hepatic enzyme activities (CAT, SOD, GCL, GR, GST, GPx) were uniformly stimulated with increasing consumption of l-methionine. As a result, hepatic content of ROS and MDA were effectively reduced by l-methionine intake. CONCLUSION: The present study demonstrates that methionine availability plays a critical role in activation of the Nrf2-ARE pathway to induce an endogenous antioxidant response for depressing ROS-derived oxidative stress, which is primarily attributed to the stimulation of methionine sulfoxide reductase expression and glutathione synthesis. © 2019 Society of Chemical Industry.

Purified Dietary Red and White Meat Proteins Show Beneficial Effects on Growth and Metabolism of Young Rats Compared to Casein and Soy Protein.

This study compared the effects of casein, soy protein (SP), red (RMP), and white meat (WMP) proteins on growth and metabolism of young rats. Compared to casein, the ratio of daily feed intake to daily body weight gain of rats was not changed by meat protein but reduced by SP by 93.3% ( P < 0.05). Feeding RMP and WMP reduced the liver total cholesterol (TC) contents by 24.3% and 17.8%, respectively ( P < 0.05). Only RMP increased plasma HDL-cholesterol concentrations (by 12.7%, P < 0.05), whereas SP increased plasma triacylglycerol, TC, and LDL-cholesterol concentrations by 23.7%, 19.5%, and 61.5%, respectively ( P < 0.05). Plasma essential and total amino acid concentrations were increased by WMP (by 18.8% and 12.4%, P < 0.05) but reduced by SP (by 28.3% and 37.7%, P < 0.05). Twenty-five liver proteins were differentially expressed in response to different protein sources. Therefore, meat proteins were beneficial for growth and metabolism of young rats compared to casein and SP.

Pleiotropic Impacts of Macrophage and Microglial Deficiency on Development in Rats with Targeted Mutation of the Csf1r Locus.

We have produced Csf1r-deficient rats by homologous recombination in embryonic stem cells. Consistent with the role of Csf1r in macrophage differentiation, there was a loss of peripheral blood monocytes, microglia in the brain, epidermal Langerhans cells, splenic marginal zone macrophages, bone-associated macrophages and osteoclasts, and peritoneal macrophages. Macrophages of splenic red pulp, liver, lung, and gut were less affected. The pleiotropic impacts of the loss of macrophages on development of multiple organ systems in rats were distinct from those reported in mice. Csf1r-/- rats survived well into adulthood with postnatal growth retardation, distinct skeletal and bone marrow abnormalities, infertility, and loss of visceral adipose tissue. Gene expression analysis in spleen revealed selective loss of transcripts associated with the marginal zone and, in brain regions, the loss of known and candidate novel microglia-associated transcripts. Despite the complete absence of microglia, there was little overt phenotype in brain, aside from reduced myelination and increased expression of dopamine receptor-associated transcripts in striatum. The results highlight the redundant and nonredundant functions of CSF1R signaling and of macrophages in development, organogenesis, and homeostasis.

Non-linear spatial modeling of rat sightings in relation to urban multi-source foci.

The brown rat has been living with humans in a wide variety of environmental contexts; it adversely affects public health by transmission of pathogens that can cause human diseases and allergies. Understanding behavioral aspects and environmental factors of pest species can contribute to their effective management and control. This aim of this study was to investigate the spatial distribution of rats in Latina district of Madrid (Spain), and its relationship with several potential multi-source foci. A focus is any particular social and environmental urban scenario that favors the clustering and proliferation of rats. We have developed a statistical framework to provide valid information on the spatial distribution and behavior of the rats around identified potential foci that favor the concentration of rats in urban environments. We extended the standard Poisson regression model by the inclusion of a multiplicative non-linear function of the distance, an unstructured random effect, and a spatial random effect to account for the spatial structure of socio-demographic and environmental covariates were also considered in the model to control for potential confusion. We found evidence of an association between the spatial distribution of rats aggregated by census tracts and distance to foci, and this association was controlled by the covariates considered in this study.

The effect of probiotics and polysaccharides on the gut microbiota composition and function of weaned rats.

Weaning is an essential and important event for infants and rodent animals, and the dietary supplementation plays a crucial role in regulating the composition and function of gut microbiota in the initial period after weaning. In this study, we investigated the potential effects of two probiotics along with three polysaccharides (PP) in weaned rats. Male SD rats, 21 days of age, were divided into two groups: one group was administered with PP for four weeks and the other was not. Body weight, food intake, gut epithelial barrier function, digestive enzyme activities, and the composition and function of gut microbiota were analyzed. The dietary PP increased the body weight and food intake, promoted gut epithelial barrier integrity, and elevated the activities of digestive enzymes. Moreover, the microbial community structure was different between the two groups. At the genus level, Bifidobacterium, Lactobacillus, and Allobaculum were significantly increased, whereas Anaerostipes, Enterococcus, and Parabacteroides were observably reduced. Furthermore, PP significantly increased amino acid metabolism, energy metabolism, and SCFA-related metabolism. This study shows that synbiotics containing probiotics (L. acidophilus NCFM and B. lactis Bi-07) in combination with polysaccharides (LBP, PCPs, and Lentinan) can modulate the composition of gut microbiota, stimulate the maturation of gut microbiota biological function, and promote the growth performance in weaned rats.

The effects of whey and soy proteins on growth performance, gastrointestinal digestion, and selected physiological responses in rats.

The objective of this work was to identify the nutritional and physiological effects of commercial soy and whey protein preparations. Wistar rats were fed with soy (S), whey (W), or casein (C) preparations as the sole dietary protein source. The nitrogen balance, body composition, changes in caecal microbiota, mucosal and bacterial enzyme activities, and allergenic potential of the preparations were analysed. The whey diet elicited greater skeletal muscle anabolism than the soy diet. Rats from the S group had the lowest values of body weight, fat, and lean mass gain. Compared to casein, soy and whey preparations decreased the protein efficiency ratio, increased N in the urine, and triggered the reduction of ammonia levels in the caecum. Changes in ß-glucuronidase and ß-galactosidase activities in the small intestine, caecum, and colon between experimental groups were observed. Significant differences were noted in the total counts of anaerobic bacteria and sulphite reducing bacteria during soy and whey treatments. This probably affected the short chain fatty acid level in caecal digesta resulting in the lowest propionic acid and total putrefactive short chain fatty acid levels during S treatment. Generally, whey preparations are a good choice for rapid bodybuilding (skeletal muscles), whereas soy preparations are more helpful during mass reduction.

Path integration in place cells of developing rats.

Place cells in the hippocampus and grid cells in the medial entorhinal cortex rely on self-motion information and path integration for spatially confined firing. Place cells can be observed in young rats as soon as they leave their nest at around 2.5 wk of postnatal life. In contrast, the regularly spaced firing of grid cells develops only after weaning, during the fourth week. In the present study, we sought to determine whether place cells are able to integrate self-motion information before maturation of the grid-cell system. Place cells were recorded on a 200-cm linear track while preweaning, postweaning, and adult rats ran on successive trials from a start wall to a box at the end of a linear track. The position of the start wall was altered in the middle of the trial sequence. When recordings were made in complete darkness, place cells maintained fields at a fixed distance from the start wall regardless of the age of the animal. When lights were on, place fields were determined primarily by external landmarks, except at the very beginning of the track. This shift was observed in both young and adult animals. The results suggest that preweaning rats are able to calculate distances based on information from self-motion before the grid-cell system has matured to its full extent.