Cells Of Obese Rats Research Articles

Вплив наночастинок золота на морфофункціональний стан гіпоталамуса та кори надниркових залоз щурів при ожирінні

The aim of our study was to compare the effects of a gold salt (sodium tetrachloroaurate) and gold nanoparticles colloidal solution on the morphofunctional state of the hypothalamus and adrenal glands of 6-month-old male rats with obesity, which was induced using a diet-induced model of metabolic disorders. The rats, modeled for obesity, were divided into three groups that received a NaCl solution, gold salt solution and colloidal solution of gold nanoparticles for 10 days. Rats of the control group received a standard diet. After the end of the experiment, the hypothalamic nuclei and adrenal glands, prepared according to the appropriate histological methods, were collected from the animals. In the paraventricular nucleus of the hypothalamus, a small-cell area of neurons was examined. In the adrenal glands, cells of three zones of the cortex were examined: glomerular, fascicular, and reticular. The results of the study showed that obesity led to the increase of functional activity in the nuclei of neurons in the small-cell region of the paraventricular nucleus of the rat hypothalamus. Functional activity increased maximally in the cells of the glomerular zone of the adrenal cortex, moderately increased in the fascicular zone, and no significant changes were recorded in the reticular zone. It was shown that the gold salt caused a decrease in the functional activity of neurons of the paraventricular nucleus of the hypothalamus in obese rats. In the glomerular zone of the adrenal cortex, the functional activity of cells significantly decreased; in the fascicular zone, the parameters of cell nuclei decreased to a greater extent; in the reticular zone, there were almost no changes. The introduction of gold nanoparticles colloidal solution caused the intensification of functional activity of the paraventricular hypothalamic nucleus cells in obese rats. In the glomerular zone of the adrenal cortex, cell parameters decreased; in the fascicular zone, cytoplasmic parameters decreased, but nuclear parameters did not change; in the reticular zone, measured values of nuclei increased and cytoplasmic parameters remained unchanged. In general, the administration of gold nanoparticles colloidal solution produced more pronounced effects than gold salt solution on cells of the paraventricular nucleus of the hypothalamus and the adrenal cortex in obese rats.

Role of Goldenberry (Fruits with Husk) Extract in Ameliorating the Architecture and Osmotic Fragility of Red Blood Cells in Obese Rats.

Goldenberry (GB) is a promising fruit that can be a constituent in many possible nourishments. No notifications were obtained regarding the impact of exposure to goldenberry extract in the viewpoint of blood rheological properties as well as erythrocyte osmotic fragility of red blood cells (RBCs) in obese rats. A substantial reduction in plasma triglyceride, total cholesterol, and LDL, with a considerable increment in HDL levels relative to the obese group (p ≤ 0.05), was observed in rats receiving low and high doses of GB, accompanied by restoration of SOD activity and GSH levels. Rheological parameters of rats' blood have been studied over a wide range of shear rates (225-1875 s-1). A significant decrease in blood viscosity in rats who received low and high doses of GB extract was compatible with every shear rate compared to the control group. The shear stress values of the obese rats reduced appreciably (p ≤ 0.05) in all values of shear rate (from 75 to 500 s-1) proportional to the control group, while in the groups that received low and high doses of GB extract, shear stress was restored to the control values. Finally, administration of GB extract significantly decreased yield stress and indices of whole blood aggregation, with an extremely substantial increment in flow rate, in rats given low or high doses of GB compared to obese ones. The result also showed a decrease in both the average raised osmotic fragility and the hemolysis rate in rats after supplementation with low and high doses of GB extract.

PO-204 Effects of hypoxia and/or endurance exercise on autophagy of skeletal muscle in rats with nutritional obesity


 Objective The globalization of obesity has become an important factor threatening human health, and the rational health of the solution has driven the exploration of experts and scholars. For this reason, this experiment uses hypoxia and exercise as interventions for 8 weeks. Changes of autophagy-related factors LC3 mRNA, p62 mRNA and energy regulation factor AMPKα2 mRNA, and cell stress-inducing factor Sestrin2 mRNA after hypoxia and/or combined endurance exercise, and explored the effect of hypoxia endurance exercise on autophagy of skeletal muscle cells To provide a reasonable experimental basis for exploring hypoxic exercise to lose weight and to prevent or reduce autophagy-related diseases.
 Methods First, a nutritional obese rat model fed with high-fat diet for 8 weeks was constructed and randomly divided into 8 groups: the normoxia group (A), the normoxic group (AE), and 16.3%. Oxygen quiet group (B) and 16.3% hypoxic exercise group (BE), 13.3% hypoxic quiet group (C), 13.3% hypoxic exercise group (CE), 11.3% hypoxic quiet group (D), 11.3% low Oxygen exercise group (DE), 10 in each group, and continued to feed with high fat diet. Secondly, establish a hypoxic and/or endurance exercise model, and the experimental experiment is expected. The rat training program is as follows: the normoxia quiet group does not perform any endurance exercise and other interventions under normoxia; the normoxic exercise group is large. The rats underwent a medium-intensity endurance exercise with a running speed of 20 m/min in a normal oxygen environment for 40 min. Similarly, rats in the hypoxic quiet group underwent continuous hypoxia intervention for 12h in the corresponding hypoxic environment; the hypoxic-binding endurance exercise group was based on the intervention of the hypoxic-quiet group, with a time of 40 min and a running speed of 20 m/ Min's medium-intensity endurance exercise. The frequency of exercise is 5 times a week (every Monday to Friday) for 8 weeks. After the last training, fasting for 24 hours, the rats were sacrificed and sampled. Biochemical indicators were used to measure blood lipids and blood glucose concentration; real-time quantitative PCR was used to detect the expression of autophagy regulators Sestrin2, AMPKɑ2 and autophagy Beclin1 and LC3II mRNA.
 Results 
 1.Nutritional obesity rat model: After 8 weeks of high-fat feeding, the body weight, Lee's index, BG, TC, TG and LDL-c concentrations in the high-fat group were significantly increased (P<0.05)
 2.Changes in morphology and blood lipids of rats: Compared with group A, the body weight, BG, TC, TG, LDL-c concentrations in the AE group were significantly decreased (P<0.05), and the HDL-c concentration was significantly increased (P<0.05). LDL-c in group D, TG and BD concentrations in group B, group C and group D were significantly decreased (P<0.05), and HDL-c concentrations in groups C and D were significantly increased (P<0.05); Compared with the group, the LDL-c and TG concentrations in the DE group were significantly lower (P<0.05), the BG concentrations in the CE group and the DE group were significantly lower (P<0.05), and the HDL-c concentration in the DE group was significantly increased (P<0.05). ).
 3.Real-time quantitative PCR showed that compared with group A, the expression of Sestrin2, Beclin1 and LC3II mRNA in skeletal muscle cells of AE group, C group and D group was significantly increased (P<0.05), and the expression of AMPKɑ2 mRNA in group D was significantly increased. Compared with AE group, the expressions of Beclin1, LC3II and AMPKɑ2 mRNA in CE group and DE group were significantly increased (P<0.05), and the expression of Sestrin2 mRNA in DE group was significantly increased (P<0.05).
 Conclusions 
 1.Three different concentrations of hypoxia and / or combined endurance exercise can reduce the body weight of obese rats, improve the blood sugar, blood lipids, hypoxia and exercise in obese rats, the effect of weight loss, blood sugar and blood lipids is more obvious.
 2.Endurance exercise, hypoxic exposure, hypoxia combined with endurance exercise can induce autophagy in skeletal muscle cells; and the cumulative stimulation effect of exercise and hypoxia is more prominent than simple endurance exercise and hypoxia exposure.
 3.Three different concentrations of hypoxia and/or combined endurance exercise can up-regulate the expression of Sestrin2, AMPKɑ2, Beclin1, and LC3II mRNA, thereby effectively activating and enhancing the autophagy level of skeletal muscle cells in obese rats, especially 11.3% hypoxia. The endurance exercise group has a more pronounced effect.

Identifikasi Sifat dan Distribusi Sel Endokrin Ghrelin di Lambung Tikus (Rattus Norvegicus): Studi Immunohis-Tokimia pada Kondisi Obesitas

Obesity is one of major nutritional problems in the world. Obesity is very dangerous, especially when concentrated in the abdomen, because it is closely linked to various diseases such as diabetes, hypertension, heart disease, which can to causing death. This study aims to identify the nature and distribution of ghrelin on gastric endocrine cells in the obese rat (Rattus norvegicus) by using immunohistochemical techniques. The results will strengthen the understanding of the role and function of ghrelin as an alternative therapeutic target on obesity. The research used gastric tissues of ten obese and control rats which were stained with avidin-biotin-peroxidase complex method of immunohistochemistry. The results showed the existence of two types of ghrelin-producing cells (open and closed types) on the gastric mucosa of control rats, and only one type of ghrelin producing cells (open type) in obese rats. The intensity of ghrelin immunoreactive positive cells was detected weak in obese rats, but very strong in control rats. Ghrelin endocrine cells mainly distributed in the basal part of the gastric mucosa of the fundus parts, with a very small number in obese rats, but highly abundant in control rats. This study confirmed the decrease of the ghrelin synthesis and secretion in obese rat (Rattus norvegicus) at the cellular level. The decrease of ghrelin synthesis is characterized by a reduction on the number of ghrelin producing cells, the disappearance of the close type of ghrelin producing cells, and the low activity of protein synthesis in the ghrelin producing cells. Ghrelin endocrine cells distributed mainly in the basal part of the gastric mucosa, especially in the fundus parts.

Functional magnetic resonance imaging and immunohistochemical study of hypothalamic function following oral glucose ingestion in rats

The hypothalamus plays a central role in the regulation of metabolism by sensing metabolic demands and releasing regulatory neurotransmitters. This study investigated the response of the hypothalamus to glucose ingestion in rats by blood oxygen level-dependent functional magnetic resonance imaging (BOLD-fMRI) and immunohistochemical techniques to determine the role of the hypothalamus in glyco-regulation during disturbances in carbohydrate metabolism. The signal intensity of the hypothalamus was monitored by fMRI for 60 minutes after oral glucose intake in 48 healthy rats (age 14 months), which included 24 normal weight rats (weighing (365 +/- 76.5) g) and 24 overweight rats (weighing (714 +/- 83.5) g). Then, 12 rats (6 normal, 6 overweight) underwent a repeat fMRI scan after consuming an equivalent amount of water without glucose on a separate day. The procedure for fMRI with water intake was the same as for glucose ingestion. fMRI data was processed using time cluster analysis and intensity averaging method. After fMRI, the expression of neuropeptide Y (NPY) and 5-hydroxytryptamine (5-HT) in the hypothalamus of all rats was determined by immunohistochemistry. Positive cells for NPY or 5-HT were counted. There was a transient, but significant, decrease in fMRI signal intensity in all rats (mean (3.12 +/- 0.78)%) in the hypothalamus within 19.5 - 25.5 minutes of oral glucose ingestion. In overweight rats, the decrease in signal intensity in response to the glucose ingestion was more markedly attenuated than that observed in normal weight rats ((2.2 +/- 1.5)% vs (4.2 +/- 0.7)% inhibition, t = 2.12, P < 0.05). There was no significant response in the hypothalamus after oral water ingestion. The percentage of NPY positive cells in obese rats were slightly lower than those in control group (21% vs 23%, t = 0.71, P > 0.05); but there was no significant difference between the two groups; the percentage of 5-HT positive cells in obese rats were significantly lower than those in the control group (22% vs 31%, t = 3.25, P < 0.01). There is a transient, but significant, decrease in BOLD signal intensity in the hypothalamus following glucose ingestion, which is similar to that observed in humans. The response of the hypothalamus to glucose ingestion was different in overweight and normal weight rats. The percentage of NPY positive cells in obese rats were lower than those in the control group, although this difference was not statistically significant. The percentage of 5-HT positive cells in obese rats was significantly lower than those in the control group.

Mechanism of Increase in Basal Lipolysis of Enlarged Adipocytes in Obese Animals

Sonication of rat fat cells caused an increase in lipolysis in the absence of lipolytic hormones (basal lipolysis) and loss of epinephrine responsiveness. Sonication of endogenous lipid droplets from fat cells also induced an increase in lipolysis in the presence of HSL. Addition of phosphatidylcholine to the sonicated lipid droplets reduced the hydrolysis of triglyceride by HSL. These results suggest that the active HSL is already present in the fat cell even in the absence of lipolytic hormone, and phosphatidylcholine on the surface of endogenous lipid droplets causes inhibition toward lipolytic action of HSL. The decrease in the surface phosphatidylcholine concentration in endogenous lipid droplets was proved to cause the increase in basal lipolysis. It is demonstrated that basal lipolysis was elevated in the enlarged fat cells of obese rats by reduction of surface phosphatidylcholine concentration of the endogenous lipid droplets.

Characterization of secretory responses in exocrine pancreas of genetically obese Zucker rats

Secretory responses of the exocrine pancreas in the obese Zucker rat with an inherited genetic disorder were compared with those in lean control rats. Amylase concentration in pancreatic acinar cells of obese rats was reduced to 62% of the control value, whereas trypsinogen concentration was increased to 269%. The activity ratio of amylase to trypsinogen in the pancreatic acini of obese rats was about one-fourth of that in controls. The activity ratio of amylase to trypsinogen in pancreatic juice released by stimulation with varying concentrations of CCK8 or carbachol in the obese rats was also reduced to one-fourth of that in control rats. The concentration of the secretagogs inducing half-maximal secretory responses (EC50) in the obese rats was almost identical to that in the controls. The downward shift of the dose-response relation for these secretagogs in the acini of obese rats was analogous to that in streptozotocin-induced diabetic rats, cold-exposed rats, or lactating rats, as demonstrated previously. The present results may be explained by the changes in enzyme content and secretory responses found in pancreatic acini of obese Zucker rats, which would be attributable mainly to congenital disturbance in "insulo-acinar axis."

Abnormal fatty acid utilization by cultured cardiac cells from 7-day-old obese Zucker rats.

Fatty acid utilization by muscle and nonmuscle heart cells in culture has been investigated in the 7-day-old Zucker rat to determine if this tissue could contribute to the lower energy expenditure reported in obese rats at the onset of obesity. The partitioning of oleate to oxidation and esterification products and the effect of genotype on this partitioning according to cell types were studied. Results showed that the fatty acid beta-oxidation and its esterification in neutral lipid was decreased by 30% in beating muscle cells from obese animals when compared with those from lean animals. In contrast, nonmuscle cells exhibited a decreased beta-oxidation alone. A similar fatty acid composition of the phospholipids was found in non-muscle cells of obese animals and their lean litter mates. In muscle cultures, palmitic and oleic acids are lower in cells of obese rats than in those of lean rats. The present study indicates that a defect in energy metabolism could be found in heart cells at the onset of obesity, suggesting that this defect is determined by intrinisic factor(s).

Calcitonin mRNA activity in young obese (fa/fa) Zucker rats

Alterations in both calcitonin (CT) secretion and plasma calcium were recently described in adult obese Zucker rats. We have investigated the CT biosynthetic activity of thyroid glands in 30-day-old obese Zucker rats (fa/fa), and their controls (Lean). Plasma calcium level was significantly increased (+0.6 mg dl ) in obese animals, but plasma phosphate was unchanged. Plasma CT levels measured by radioimmunoassay (RIA) were significantly decreased in fatty (0.50 ± 0.03 vs 0.68 ± 0.03 ng ml in Leans; P < 0.001), but thyroidal hormone content was not different between Lean and fatty rats (68.7 ± 5.1 in Leans vs 60.5 ± 3.6 ng gland in fatty rats). mRNA was extracted from 10 thyroids, and translated in a rabbit reticulocyte lysate (NEN) in the presence of [ 35S]methionine. After polyacrylamide gel electrophoresis, specific immunoprecipitates were autoradiographied and quantified by integration. A 50% decrease in translatable CT mRNA was observed in fatty rats. In basal conditions, the biosynthetic activity of C cells in obese rats correlates with the secretion rate of the hormone in the face of unchanged thyroidal CT contents.

Effect of Dehydroepiandrosterone on Growth in Lean and Obese Zucker Rats

Several studies were undertaken to determine the effect of dehydroepiandrosterone (DHEA) on growth in Zucker rats. In experiment 1, 3 weeks of DHEA treatment in lean rats resulted in decreased body weight gain in comparison to control rats. In experiment 2, both lean and obese rats were treated with DHEA from 6 to 21 weeks of age. Significant decreases in body weight were found for both lean and obese DHEA-treated rats. The food efficiency ratio (FER) was significantly decreased in both DHEA-treated groups. Significant decreases in parametrial and retroperitoneal fat pads were found in both lean and obese DHEA-treated rats. This was primarily attributed to a decrease in fat cell number in lean rats and to decreases in both number and size of fat cells in obese rats. In experiment 3 obese female rats were treated with DHEA from 6 to 21 weeks of age followed by 15 weeks with DHEA removed from the diet. Significantly more weight was gained by the rats previously treated than by the control rats, but body weight remained significantly lower than in the control groups. These data indicate DHEA has an effect on altering body weight and body fat in lean and obese Zucker rats.

Cyclic Adenosine Monophosphate-dependent Phosphorylation of Specific Fat Cell Membrane Proteins by an Endogenous Membrane-bound Protein Kinase: POSSIBLE INVOLVEMENT IN THE REGULATION OF INSULIN-STIMULATED GLUCOSE TRANSPORT

Abstract The phosphorylation of specific membrane proteins by an endogenous protein kinase has been studied in purified membrane fractions from rat adipocytes using trichloroacetic acid precipitation and sodium dodecyl sulfate polyacrylamide disc gel electrophoresis. The endogenous phosphorylation of two specific membrane proteins is completely dependent on the presence of cyclic adenosine 3':5'-monophosphate (cyclic AMP) and magnesium ions. This phosphorylation occurs very rapidly at 24°, reaching maximal levels at 1 min. The number of sites specifically phosphorylated in the presence of cyclic AMP probably does not exceed 50,000 per fat cell, requiring the use of very high specific activity (10 to 50 Ci per mmole) [γ-32P]ATP for these studies. The minimal molecular weights of the two specifically phosphorylated proteins are about 22,000 and 16,000 as determined by gel electrophoresis in the presence of sodium dodecyl sulfate. The same two proteins are phosphorylated when intact fat cells are exposed briefly to low concentrations of exogenous ATP, a process which results in the suppression of the insulin-stimulated rates of d-glucose transport. At least 95 % of the cyclic AMP-dependent 32P incorporated into trichloroacetic acid-precipitable protein is in the form of protein-bound phosphoserine. The concentration of cyclic AMP required for maximal stimulation of phosphorylation is about 1.5 µm. Cyclic guanosine 3':5'-monophosphate has no significant effect unless its concentration is increased to 10-4 m. Phosphorylation is inhibited by calcium ions. The cyclic AMP-stimulated phosphorylation is inhibited by phloretin and by 5'-adenylyl-β, γ-methylene triphosphonate. The specific cyclic AMP-dependent membrane phosphorylation is also found in membranes from cells of obese rats, an insulin-resistant animal. This phosphorylation system, however, cannot be detected in membranes from guinea pig fat cells. The lack of phosphorylation of specific membrane proteins in guinea pig fat cell membranes is correlated with the insulin insensitivity of this tissue to glucose transport (but not lipolysis) and with the inability of ATP to inhibit the slight stimulation which insulin exerts on glucose transport. The possibility is considered that this specific cyclic AMP-dependent phosphorylating system is involved in the hormonal regulation of glucose transport and the modulation of insulin sensitivity.