Relation of polysome structure to ribonuclease and ribonuclease inhibitor activities in livers of magnesium-deficient guinea pigs

1970 ◽  
Vol 48 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Neville D. Grace ◽  
Boyd L. O'Dell
Keyword(s):  
Food Intake ◽  
Guinea Pigs ◽  
Magnesium Deficiency ◽  
Control Diet ◽  
Nitrogen Concentration ◽  
Dietary Treatment ◽  
Ribonuclease Activity ◽  
Ribonuclease Inhibitor ◽  
Adequate Diet ◽  
Ad Libitum

The hepatic polysomes isolated from magnesium-deficient guinea pigs did not contain the 131 S ribosomal unit found in the polysomes of control animals that consumed an adequate magnesium diet ad libitum. A 64 S particle not present in the controls appeared in the deficient polysomes. Restriction of the adequate diet to the quantity consumed by the deficient animals (pair-fed) had no effect on the polysome pattern, but restriction so as to maintain the same body weight (pair-weighted) caused dissociation similar to that of magnesium deficiency. Alkaline ribonuclease activity determined on total homogenates and expressed on the basis of nitrogen concentration was significantly higher in the livers of the magnesium-deficient and pair-weighted animals than in animals pair-fed or ad libitum fed the control diet. Acid ribonuclease activity in the magnesium-deficient animals was also significantly higher than in the pair-fed and ad libitum fed controls. Dietary treatment had no significant effect on the concentration of ribonuclease inhibitor in the liver. It was concluded that the effect of dietary magnesium deficiency in decreasing polysome stability is indirect and may be induced as well by severely reduced food intake. However, restricting food intake to the level consumed by magnesium-deficient animals did not decrease polysome size. It is postulated that this difference is due to an effect of low extracellular magnesium on nutrient transport.

P0919CALORIC RESTRICTION DOES NOT PROTECT AGAINST THE DEVELOPMENT OF VASCULAR CALCIFICATION

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Rafael Ríos-Varo ◽  
Ángela Vidal ◽  
Ana Isabel Raya ◽  
Carmen Pineda ◽  
Ignacio López ◽  
...  
Keyword(s):  
Food Intake ◽  
Vascular Calcification ◽  
Control Diet ◽  
Plasma Concentrations ◽  
Caloric Intake ◽  
Metabolizable Energy ◽  
High Rate ◽  
Caloric Content ◽  
Ad Libitum ◽  
Group 1

Abstract Background and Aims Vascular calcification (VC) is an important contributor to the high rate of cardiovascular mortality associated to chronic kidney disease. The inability to eliminate phosphorus (P) and the subsequent P retention promotes CV. P metabolism and uremic VC are influenced by obesity and by the caloric content of the diet. Caloric restriction (CR) has been shown to have multiple beneficial effects on health, for example, CR has been reported to improve vascular health and retard vascular ageing. However, to our knowledge the effect of CR on the development of uremic VC has not been explored. We hypothesize that CR may be beneficial to prevent the development of uremic VCs. Thus, the objective of the present study was to determine if rats subjected to CR were protected against VC. Method 48 Wistar rats were divided in four groups. The control diet provided Metabolizable Energy = 3.528 kcal/g and contained 0.6% Calcium (Ca) and 0.6% P. Additional diets of identical composition to the control diet but containing varying levels of Ca and P: 0.9% Ca, 0.9% P; 0.6% Ca, 1.2% P; and 0.9% Ca, 1.8% P, were also used in the experiments. Rats in Group 1 and 3 were fed 15 g/day of the control diet. Rats in Group 2 and 4 were calorie restricted and fed 10 g/day of diet with Ca/P = 0.9%/0.9%. Thus the daily P intake should be identical in the four groups. Uremia was induced by 5/6 nephrectomy (Nx). After Nx rats in Group 1 and 2 were fed ad libitum a diet with 0.6% Ca and 1.2% P. While rats in Group 3 and 4 were fed ad libitum a diet with 0.9% Ca and 1.8% P. Rats were supplemented with calcitriol. At the end of the experiment, rats were sacrificed to obtain blood samples and tissue samples (thoracic and abdominal aortas). After blood collection, plasma was separated by centrifugation and stored at –20° C until assayed. Plasma creatinine, Ca and P were measured by spectrophotometry. Energy intake was calculated based on food intake. VC was studied by histology and by measuring the tissue Ca content. Values are expressed as mean ± standard error (SE), the difference between groups was assessed by ANOVA. Fisher LSD test was used as a post-hoc procedure. p<0.05 was considered significant. Results Before Nx, caloric intake was significantly lower in calorie restricted rats (35.4 ± 0.1 and 35.8 ± 0.1 kcal/day) than in rats eating normal calories (52.7 ± 0.1 and 52.8 ± 0.2 kcal/day); however, P intake was almost identical in the four groups and ranged between 89.8 and 91.6 mg/day. After Nx, rats in all groups reduced food intake and, consequently, caloric intake. Thus, although the P content of the diet was increased after Nx, daily P intake was not increased in Groups 1 and 2; however, P intake was significantly increased in Groups 3 and 4 (120.9 ± 4.6 and 122.2 ± 6.2 mg/day, respectively). In all groups, rats had high plasma concentrations of creatinine and P, and low plasma concentrations of Ca. Also, all rats had elevated Ca content in the aorta. No significant differences between the study groups were found in any of these parameters (Table 1). Von Kossa staining of the aortas showed abundant mineral deposition in the four groups. Conclusion This study shows that, contrary to what was expected, CR did not prevent or ameliorate uremic calcifications.

scholarly journals Rapamycin induced hyperglycemia is associated with exacerbated age-related osteoarthritis

2021 ◽  
Author(s):  
Dennis M Minton ◽  
Christian J Elliehausen ◽  
Martin A M Javors ◽  
Kelly S Santangelo ◽  
Adam R Konopka
Keyword(s):  
Body Weight ◽  
Articular Cartilage ◽  
Plasma Glucose ◽  
Guinea Pigs ◽  
Structural Damage ◽  
Control Diet ◽  
Dietary Treatment ◽  
Micro Computed Tomography ◽  
Mtor Inhibition ◽  
Age Related

Objective: Determine if mechanistic target of rapamycin (mTOR) inhibition and/or AMP-activated protein kinase (AMPK) activation can modify primary osteoarthritis (OA). Design: Dunkin-Hartley guinea pigs develop mild primary OA pathology by 5-months of age that progresses to moderate OA by 8-months of age. At 5-months, guinea pigs were fed either a control diet (n=8) or a diet enriched with the mTOR-inhibitor rapamycin (Rap, 14ppm, n=8), the AMPK-activator metformin (Met, 1000ppm, n=8), or the combination of rapamycin plus metformin (Rap+Met, 14+1000ppm, n=7) for 12 weeks. Knee joints were evaluated by OARSI scoring, micro-computed tomography, and immunohistochemistry. Glenohumeral articular cartilage was collected for western blotting. Results: Dietary treatment with Rap and Rap+Met decreased body weight compared to control. Rap and Rap+Met inhibited articular cartilage mTORC1 but not mTORC2 signaling. Rap+Met, but not Rap or Met alone, stimulated AMPK. Despite lower body weight and articular cartilage mTORC1 inhibition, Rap and Rap+Met treated guinea pigs had greater OA severity in the medial tibial plateau due to articular cartilage structural damage and/or proteoglycan loss. Rap and Rap+Met increased plasma glucose compared to control. Plasma glucose concentration was positively correlated with OA pathology. Conclusions: This is the first study to show that Rap induced increase in plasma glucose was associated with greater OA severity. Further, articular cartilage mTORC1 inhibition and bodyweight reduction by dietary Rap were insufficient to protect against primary OA during the prevailing hyperglycemia.

Food intake, eating rate, weight gains, metabolic rate and efficiency of feed utilization in Bos taurus and Bos indicus crossbred cattle

1977 ◽  
Vol 25 (3) ◽  
pp. 343-358 ◽  
Author(s):  
J. E. Frisch ◽  
J. E. Vercoe
Keyword(s):  
Food Intake ◽  
Metabolic Rate ◽  
Bos Taurus ◽  
Bos Indicus ◽  
Live Weight ◽  
Dietary Treatment ◽  
Eating Rate ◽  
Ad Libitum ◽  
The Difference ◽  
Voluntary Food Intake

SUMMARYFood intake, eating rate, weight change and fasting metabolic rate were measured on 12 animals of each of the following breed-types: Hereford × Shorthorn (HS), Brahman × HS (BX) and Africander × HS (AX). Measurements were made on ad libitum and fixed levels of lucerne and ad libitum and fixed levels of low-quality tropical pasture hay (approx. 1·2% N) during feeding periods of about 100 days' duration.The BX and AX were heavier and either gained more weight or lost less weight than the HS on all diets. At feeding levels close to maintenance, which included the ad libitum pasture hay diet, adjustment for differences in either live weight or intake did not alter the unadjusted ranking of the breeds. On ad libitum lucerne, however, adjustment for either weight or intake showed higher gain in the HS than in the BX. The voluntary food intake per kg live weight was consistently and significantly highest for the HS and lowest for the BX. Rates of eating were not significantly different for the different breed-types but they were higher for high-quality lucerne and for the lower level of feeding. Fasting metabolic rate per kg live weight was highest for the HS and lowest for the BX; the difference between the breeds varied with the previous dietary treatment. The ratio of voluntary food intake to fasting metabolism was practically constant between breeds and animals within breeds, though different between diets.Correlations for animals within breeds and years between the various parameters within diets and between diets are presented.

Physical and Chemical Characteristics of Meats of the Indonesian Indigenous Crossbred Chickens Fed Fermented Mixture of Papaya (Carica papaya L.) Leaf and Seed Meal

2020 ◽  
Keyword(s):  
Crude Protein ◽  
Control Diet ◽  
Dietary Treatment ◽  
Seed Meal ◽  
Chemical Characteristics ◽  
Breast Meat ◽  
Ph Values ◽  
Physical And Chemical Characteristics ◽  
Dietary Treatments ◽  
Physical And Chemical

The objective of this present study was to investigate the effect of feeding fermented mixture of papaya leaf and seed meal (FERM) on the physical and chemical characteristics of meats of the Indonesian indigenous crossbred chicken (IICC). The study was carried out with 300 day-old IICC. The chicks were randomly distributed to five treatment groups, i.e., CONT (control diet based on corn-soybean- diet), FERMA (diet containing 1% FERM), FERMB (2.5% FERM), FERMC (5% FERM) and FERMD (7.5% FERM). Each treatment group consisted of 6 replicates with 10 IICC in each. At week 8, one chick from each replicate was randomly taken and slaughtered. After being de-feathered and eviscerated, samples from breast and thigh meats were obtained. Results showed that the increased levels of FERM was followed by the increased (P<0.05) pH values, moisture and crude protein content of breast meats of the IICC. Dietary incorporation of FERM especially at the level of 2.5% increased (P<0.05) the content of fat in the breast meat of IICC, while further increased levels of FERM did not alter (P>0.05) the fat content of the IICC breast meat. Dietary treatment did not have any effect (P>0.05) on the lightness (L*) values of breast meat of the IICC. The redness (a*) values were higher (P<0.05) in FERMD breast meat than other. FERM diet resulted in lower (P<0.05) yellowness (b*) values in the IICC breast meat. The pH values and moisture content of thigh meat increased (P<0.05) with the increased level of FERM. The WHC decreased (P<0.05) with the elevated levels of FERM in the diets. There was an increase (P<0.05) in crude protein concentration in FERMA as compared to the other meats. Crude fat and ash concentrations in thigh meat were affected (P<0.05) by the treatments. Dietary treatments had no impact (P>0.05) on L* values of thigh meats. Feeding FERM at 7.5% from diets increased (P<0.05) and decreased (P<0.05) the redness and yellowness of meats. In conclusion, dietary inclusion of FERM especially at the level of 7.5% from diets improved the physical and chemical characteristics of the IICC meats.

ACCELERATION OF ANNUAL HIBERNATING CYCLE TO 6 WEEKS IN CAPTIVE DORMICE

1966 ◽  
Vol 44 (5) ◽  
pp. 903-910 ◽  
Author(s):  
N. Mrosovsky
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Sunflower Seed ◽  
Body Temperatures ◽  
Glis Glis ◽  
Ad Libitum

Cycles of food intake and body weight lasting a few weeks occurred in dormice, Glis glis, kept in the laboratory in relatively constant conditions of temperature (about 25 °C) and photoperiod (about 12 hours light–dark schedule). These fluctuations appeared to be more marked in the winter months. Periods of reduced eating were associated with low body temperatures and lethargy. The frequent disturbance and arousal of the animals was probably an important factor in these short hibernating cycles. The influence of variation of the diet on body weight of dormice is described. Animals kept on ad libitum supplies of sunflower seed became obese and remained so for many months.

scholarly journals Impaired branched chain amino acid metabolism alters feeding behavior and increases orexigenic neuropeptide expression in the hypothalamus

2011 ◽  
Vol 212 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Megan N Purpera ◽  
Li Shen ◽  
Marzieh Taghavi ◽  
Heike Münzberg ◽  
Roy J Martin ◽  
...  
Keyword(s):  
Amino Acid ◽  
Food Intake ◽  
Feeding Behavior ◽  
Control Diet ◽  
Peripheral Tissues ◽  
Protein Status ◽  
Branched Chain Amino Acid ◽  
Branched Chain ◽  
Branched Chain Aminotransferase ◽  
Deficient Mice

Elevation of dietary or brain leucine appears to suppress food intake via a mechanism involving mechanistic target of rapamycin, AMPK, and/or branched chain amino acid (BCAA) metabolism. Mice bearing a deletion of mitochondrial branched chain aminotransferase (BCATm), which is expressed in peripheral tissues (muscle) and brain glia, exhibit marked increases in circulating BCAAs. Here, we test whether this increase alters feeding behavior and brain neuropeptide expression. Circulating and brain levels of BCAAs were increased two- to four-fold in BCATm-deficient mice (KO). KO mice weighed less than controls (25.9 vs 20.4 g,P<0.01), but absolute food intake was relatively unchanged. In contrast to wild-type mice, KO mice preferred a low-BCAA diet to a control diet (P<0.05) but exhibited no change in preference for low- vs high-protein (HP) diets. KO mice also exhibited low leptin levels and increased hypothalamicNpyandAgrpmRNA. Normalization of circulating leptin levels had no effect on either food preference or the increasedNpyandAgrpmRNA expression. If BCAAs act as signals of protein status, one would expect reduced food intake, avoidance of dietary protein, and reduction in neuropeptide expression in BCATm-KO mice. Instead, these mice exhibit an increased expression of orexigenic neuropeptides and an avoidance of BCAAs but not HP. These data thus suggest that either BCAAs do not act as physiological signals of protein status or the loss of BCAA metabolism within brain glia impairs the detection of protein balance.

scholarly journals Neuropeptide Y1 and Y5 Receptors Mediate the Effects of Neuropeptide Y on the Hypothalamic-Pituitary-Thyroid Axis

Endocrinology ◽  
2002 ◽  
Vol 143 (12) ◽  
pp. 4513-4519 ◽  
Author(s):  
Csaba Fekete ◽  
Sumit Sarkar ◽  
William M. Rand ◽  
John W. Harney ◽  
Charles H. Emerson ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Food Intake ◽  
Neuropeptide Y ◽  
Paraventricular Nucleus ◽  
Receptor Agonist ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
Ad Libitum ◽  
Thyroid Hormone Levels ◽  
Hpt Axis

Abstract Neuropeptide Y (NPY) is one of the most important hypothalamic-derived neuropeptides mediating the effects of leptin on energy homeostasis. Central administration of NPY not only markedly stimulates food intake, but simultaneously inhibits the hypothalamic-pituitary-thyroid axis (HPT axis), replicating the central hypothyroid state associated with fasting. To identify the specific NPY receptor subtypes involved in the action of NPY on the HPT axis, we studied the effects of the highly selective Y1 ([Phe7,Pro34]pNPY) and Y5 ([chicken pancreatic polypeptide1–7, NPY19–23, Ala31, Aib32 (aminoisobutyric acid), Q34]human pancreatic polypeptide) receptor agonists on circulating thyroid hormone levels and proTRH mRNA in hypophysiotropic neurons of the hypothalamic paraventricular nucleus. The peptides were administered continuously by osmotic minipump into the cerebrospinal fluid (CSF) over 3 d in ad libitum-fed animals and animals pair-fed to artificial CSF (aCSF)-infused controls. Both Y1 and Y5 receptor agonists nearly doubled food intake compared with that of control animals receiving aCSF, similar to the effect observed for NPY. NPY, Y1, and Y5 receptor agonist administration suppressed circulating levels of thyroid hormones (T3 and T4) and resulted in inappropriately normal or low TSH levels. These alterations were also associated with significant suppression of proTRH mRNA in the paraventricular nucleus, particularly in the Y1 receptor agonist-infused group [aCSF, NPY, Y1, and Y5 (density units ± sem), 97.2 ± 8.6, 39.6 ± 8.4, 19.9 ± 1.9, and 44.6 ± 8.4]. No significant differences in thyroid hormone levels, TSH, or proTRH mRNA were observed between the agonist-infused FSanimals eating ad libitum and the agonist-infused animals pair-fed with vehicle-treated controls. These data confirm the importance of both Y1 and Y5 receptors in the NPY-mediated increase in food consumption and demonstrate that both Y1 and Y5 receptors can mediate the inhibitory effects of NPY on the HPT axis.

scholarly journals Dietary sodium requirement determined for juvenile hybrid tilapia (Oreochromis niloticus × O. aureus) reared in fresh water and seawater

2004 ◽  
Vol 91 (4) ◽  
pp. 585-590 ◽  
Author(s):  
Shi-Yen Shiau ◽  
Li-Shan Lu
Keyword(s):  
Weight Gain ◽  
Atpase Activity ◽  
Fresh Water ◽  
Oreochromis Niloticus ◽  
Polynomial Regression ◽  
Control Diet ◽  
Dietary Treatment ◽  
Basal Diet ◽  
Dietary Sodium ◽  
Whole Body

Two 8-week feeding trials were conducted to determine the dietary Na requirement for juvenile hybrid tilapia (Oreochromis niloticus × O. aureus) reared in fresh water and seawater. In each experiment, NaCl was added to the basal diet at 0, 0·5, 1, 2, 3, 5, or 7g Na/kg diet (fresh water) and at 0, 0·2, 0·5, 0·8, 1·2, 1·5, 2, or 3g Na/kg diet (seawater). Each diet was fed to three replicate groups of fish, individual fish initially weighing 0·69 (se 0·01) g, in a closed, recirculating rearing system. In fresh water, the tilapia fed the diet supplemented with 2g Na/kg diet had significantly (P<0·05) greater weight gain than the fish fed the diets supplemented with ≥3 and ≤0·5g Na/kg diet. Feed efficiency (FE) in fish generally followed the weight-gain pattern. Gill Na+–K+ ATPase activity was highest in the fish fed the diets supplemented with 1–3g Na/kg diet, followed by the fish fed the diet with 7g Na/kg diet and lowest in the fish fed the unsupplemented control diet. In seawater, the weight gain, FE and gill Na+–K+ ATPase activity in fish were not affected by the dietary treatment. Analysis by polynomial regression of weight gain, by broken-line regression of gill Na+–K+ ATPase activity and by linear regression of whole-body Na retention of the fish reared in fresh water, indicated that the adequate dietary Na concentration for tilapia is about 1·5g/kg diet. The present study also suggests that no dietary Na is required for tilapia reared in seawater.

scholarly journals On the origin of the increased tissue iron content in graded magnesium deficiency states in the rat

1997 ◽  
Vol 77 (3) ◽  
pp. 475-490 ◽  
Author(s):  
Klaus Schumann ◽  
Annette Lebeau ◽  
Ursula Gresser ◽  
Theodor Gunther ◽  
Jürgen Vormann
Keyword(s):  
Haemolytic Anaemia ◽  
Rapid Growth ◽  
Magnesium Deficiency ◽  
Erythropoietic Activity ◽  
Mg Deficiency ◽  
Adequate Diet ◽  
Fe Content ◽  
High Degree

To investigate the mechanism of tissue Fe accumulation in graded Mg deficiency rats were fed on diets of different Mg contents (70, 110, 208, 330, and 850 mg Mg/kg) for 10, 20, and 30 d during rapid growth. There was no significant impact of Mg deficiency or high luminal Mg concentrations on intestinal59Fe transferin vitroorin vivo. Plasma Mg concentrations and body weight started to decrease after 10 d. Significant haemolytic anaemia was observed after 20 d with siderosis in liver and spleen developing in parallel. Anaemia showed no features of Fe deficiency or infiammation. Comparison between the 70 mg Mg/kg group and animals that received the same quantity of a Mg-adequate diet (850 mg Mg/kg) permitted estimation of quantities of Fe liberated by haemolysis and the increased Fe content in liver and spleen. Both variables showed a high degree of correlation, indicating that the excess of liberated haemoglobin Fe was stored in the tissue. The erythropoietic activity was high during rapid growth, i.e. at days 10 and 20 and decreased significantly after 30 d in all except the most Mg-deficient groups. However, haemolytic anaemia developed because even the high erythropoietic activity in the 70 and 110 mg Mg/kg groups was not sutlicient to recycle all haemoglobin Fe liberated by haemolysis. After 30 d of Mg-deficient feeding the erythrocyte Mg content had decreased to 40% of control values. According to the literature Mg-deficient erythrocytes have a decreased survival time which is likely to be the cause of the observed haemolysis.

Feeding performance of juvenile marble goby (Oxyeleotris marmorata Bleeker, 1852) fed acidified diets

2018 ◽  
Vol 26 (4) ◽  
pp. 211-216
Author(s):  
Leong-Seng Lim ◽  
Chui-Fen Teoh ◽  
Gunzo Kawamura ◽  
Annita Seok-Kian Yong ◽  
Rossita Shapawi
Keyword(s):  
Body Length ◽  
Fish Meal ◽  
Control Diet ◽  
Dietary Treatment ◽  
Feeding Trial ◽  
Feeding Performance ◽  
Daily Ingestion ◽  
Ph Level ◽  
Ingestion Ratio ◽  
And Control

Abstract The present study aimed to evaluate the feeding performance of juvenile marble goby (Oxyeleotris marmorata) on acidified diets. Five fish meal-based diets at various pH levels (2.5, 3.2, 4.3, 5.3, and 6.0 (control)) were prepared, and each of them was fed to 10 wild-caught O. marmorata juveniles (body length 7.7–9.3 cm; each fish was placed in an aquarium, hence each dietary treatment was in 10 replicates) for 20 days. Throughout the feeding trial, O. marmorata juveniles showed clear increments in the daily ingestion ratio (IR) values of AD 2.5, AD 3.2, and AD 4.3. The control diet and AD 5.3 were almost totally rejected by the fish. On day 20, the IR of AD 2.5 (0.46) and AD 3.2 (0.36) were significantly higher (P < 0.05) than those of AD 5.3 (0.1) and the control diet (0.02). In addition, 70% of fish fed AD 2.5 achieved a high IR value (0.6 – 1.0), and this was the best result among all the treatments (AD 3.2, 60%; AD 4.3 50%; AD 5.3 and control, 10%). These results suggested that acidified diets can be used to wean O. marmorata juveniles, and the recommended pH level was 2.5.

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