scholarly journals Changes in mineralization and biomechanics of tibial metaphyses in splinted rats

2005 ◽  
Vol 99 (1) ◽  
pp. 173-180 ◽  
Author(s):  
R. G. Lentle ◽  
M. C. Kruger
Keyword(s):  
Local Effect ◽  
Sprague Dawley ◽  
Mineral Density ◽  
Mineral Contents ◽  
Breaking Strain ◽  
Sprague Dawley Rats ◽  
Metaphyseal Bone ◽  
Breaking Energy ◽  
The Relationship ◽  
Femoral Size

The effect of 3 wk of splintage of a single hindlimb on the midarea and mineral content of both tibial metaphyses was assessed immediately after splint removal and after 1 mo of mobilization in 12-wk-old Sprague-Dawley rats. Immobilization reduced tibial metaphyseal bone mineral density (BMD) in immobilized limbs compared with “free” limbs of splinted animals and with controls. These changes persisted and were accentuated by relatively greater increases in tibial metaphyseal BMDs of unsplinted (control) animals after 7 wk. Immediately after splintage, tibial metaphyseal areas and total mineral contents of both hindlimbs of splinted animals were reduced compared with those of unsplinted animals. However, the relationship between mineralization and area differed between the free and immobilized limbs of splinted animals. The breaking strain and the breaking energy of immobilized and free femurs of splinted animals were impaired 4 wk after the removal of the splint. This impairment was correlated with an effect of splintage on femoral size with some additional local effect from immobilization. Thus osteoporotic changes consequent on immobilization include both local effects on mineralization and general effects on growth, which may separately influence the elastic properties of bone.

scholarly journals Prolonged feeding of difructose anhydride III increases strength and mineral concentrations of the femur in ovariectomized rats

2005 ◽  
Vol 94 (2) ◽  
pp. 268-274 ◽  
Author(s):  
Rieko Mitamura ◽  
Hiroshi Hara
Keyword(s):  
Bone Strength ◽  
Ovariectomized Rats ◽  
Control Group ◽  
Sprague Dawley ◽  
Mineral Density ◽  
Ovx Rats ◽  
Sprague Dawley Rats ◽  
Promotive Effect ◽  
Mineral Concentrations ◽  
The Relationship

This study demonstrates that feeding difructose anhydride III (DFAIII) improves bone strength and femoral mineral concentrations in a rat model of oestrogen deficiency. We showed the relationship between Ca, Mg and P absorption and bone characteristics in rats. Two groups of female Sprague-Dawley rats (6 weeks old) underwent bilateral ovariectomy (ovariectomized rats, OVX rats) or bilateral laparotomy (sham rats). At 10 weeks old, OVX and sham rats were divided into three subgroups and fed a control, 1·5 % DFAIII or 3 % DFAIII diet for 8 weeks, respectively. Ca but not Mg absorption rates were lowered by ovariectomy; however, ingestion of the 1·5 % and 3 % DFAIII diets similarly restored the reduced Ca absorption in OVX rats at 4 and 8 weeks after feeding of the test diets. DFAIII increased Mg absorption dose-dependently in sham and OVX rats. The bone strength, femoral Ca and Mg concentrations, and distal bone mineral density in the 3 % DFAIII group were higher than those in the control group in OVX rats. The absorption rates of Ca and Mg were significantly correlated with femoral Ca and Mg concentrations and strength, which suggests that increasing both Ca and Mg absorption improves bone characteristics in OVX rats. There were no differences in any of the variables in the femur between the 1·5 % and 3 % DFAIII groups in OVX rats. In conclusion, feeding of a low dose of DFAIII increased intestinal Ca and Mg absorption, and the promotive effect of DFAIII persisted for over 8 weeks. This effect was associated with prevention of ovariectomy-induced osteopenia.

Time course of airway hyperresponsiveness and remodeling induced by hyperoxia in rats

1995 ◽  
Vol 269 (2) ◽  
pp. L227-L233 ◽  
Author(s):  
J. L. Szarek ◽  
H. L. Ramsay ◽  
A. Andringa ◽  
M. L. Miller
Keyword(s):  
Smooth Muscle ◽  
Airway Hyperresponsiveness ◽  
Time Course ◽  
Electrical Field Stimulation ◽  
Maximal Response ◽  
Sprague Dawley ◽  
Electrical Field ◽  
Muscle Area ◽  
Sprague Dawley Rats ◽  
The Relationship

The purpose of this study was to answer two questions concerning hyperoxia-induced airway hyperresponsiveness: 1) What is the time course of the development of airway hyperresponsiveness? 2) What is the relationship between the increase in responsiveness and smooth muscle area? Segments of intrapulmonary bronchi were isolated from male Sprague-Dawley rats that had been exposed to 80-85% O2 for a period of 1, 3, 5, or 7 days and from aged-matched control animals that breathed room air. Hyperoxia increased the sensitivity (log concentration or frequency that elicited a half-maximal response) and reactivity (maximum tension developed) of the airways to electrical field stimulation (EFS) after 3, 5, and 7 days; sensitivity to acetylcholine was not affected, but reactivity was increased after 7 days. Hyperoxia increased smooth muscle area beginning 5 days after commencing the exposure. After normalizing tension responses to smooth muscle area, reactivity of the airways to the stimuli was not different between the two groups, but sensitivity to EFS was still increased. The increase in reactivity observed after 5 and 7 days of exposure can be explained by an increase in smooth muscle area that occurred at these time points. The fact that the sensitivity of the airways to EFS remained increased after normalization, together with the fact that the increase in airway responsiveness after 3 days of exposure occurred at a time when smooth muscle area was not different from control, suggests that mechanisms other than increased smooth muscle area contribute to the development of hyperoxia-induced airway hyperresponsiveness.

Defect in the Renal Tubular Reabsorption of Water Associated With Potassium Depletion in Rats

1957 ◽  
Vol 189 (3) ◽  
pp. 557-563 ◽  
Author(s):  
Walter Hollander ◽  
Robert W. Winters ◽  
T. Franklin Williams ◽  
John Bradley ◽  
Jean Oliver ◽  
...  
Keyword(s):  
Urinary Concentration ◽  
Potassium Depletion ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Renal Tubular Reabsorption ◽  
Renal Concentrating Mechanism ◽  
Renal Tubular ◽  
Relationship Of ◽  
The Relationship ◽  
K Depletion

The effect of graded degrees of K depletion on the ability to produce a concentrated urine was studied in Sprague-Dawley rats. With increasing degrees of K depletion, as measured by the concentration of K in fat-free skeletal muscle, there was a progrossive decrease in the maximum urinary concentration. This defect of the renal concentrating mechanism appeared to be better correlated with the degree than with the duration of potassium depletion and could be demonstrated either by the use of exogenous vasopressin or by water deprivation. The potassium-deficient rats in at least one experiment developed a significant polydipsia. The data do not allow any conclusions with respect to the relationship of the polydipsia to the renal concentrating defect except that the latter at least was not severe at the onset of the increased water intake.

Microflora-derived polyamines modulate obstruction-induced colonic mucosal hypertrophy

1989 ◽  
Vol 256 (6) ◽  
pp. G1049-G1057 ◽  
Author(s):  
D. L. Osborne ◽  
E. R. Seidel
Keyword(s):  
Colonic Obstruction ◽  
Arginine Decarboxylase ◽  
Local Effect ◽  
Decarboxylase Activity ◽  
Intestinal Epithelial ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Mucosal Response ◽  
Mucosal Hypertrophy

Experiments were designed to determine the role of microflora-derived intraluminal polyamines in the colonic mucosal response to obstruction. Sprague-Dawley rats were treated per os with 0.9% NaCl or a combination of nonabsorbable antibiotics prior to the placement of either a sham or complete colonic obstruction. Sixty-six hours after surgery, wet tissue weight, DNA, RNA, and protein content were all increased in the mucosa proximal to the obstruction in NaCl-treated animals; however, DNA content was the only parameter increased after antibiotics. This induction was a purely local effect as neither hyperplasia nor hypertrophy was observed in the ileum or colon distal to the obstruction. In the NaCl-treated animals, mucosal ornithine decarboxylase activity was not induced until 48 h postsurgery, yet mucosal spermidine concentrations were significantly higher as early as 24 h. Intraluminal bacterial lysine, ornithine, and arginine decarboxylase activities were induced by obstruction but were reduced by antibiotic treatment. [14C]putrescine uptake by intestinal epithelial cells (IEC-6) in culture was blocked by the antibiotics employed in this study, but [14C]-lysine transport was relatively unaffected. These data demonstrate that intraluminal polyamines modulate the trophic response of the colonic mucosa after colonic obstruction.

Hindbrain GRP receptor blockade antagonizes feeding suppression by peripherally administered GRP

1996 ◽  
Vol 271 (1) ◽  
pp. R180-R184 ◽  
Author(s):  
E. E. Ladenheim ◽  
J. E. Taylor ◽  
D. H. Coy ◽  
K. A. Moore ◽  
T. H. Moran
Keyword(s):  
Food Intake ◽  
Critical Role ◽  
Intraperitoneal Administration ◽  
Reduce Food Intake ◽  
Sprague Dawley ◽  
Glucose Intake ◽  
Sprague Dawley Rats ◽  
Feeding Effects ◽  
Grp Receptors ◽  
The Relationship

Bombesin (BN)-like peptides injected peripherally or centrally suppress food intake in rats. The relationship between the central and peripheral actions of BN is unknown. However, experimental evidence supports a critical role for the caudal hindbrain in mediating the feeding effects of BN. To investigate this relationship further, we examined the ability of fourth ventricular infusion of a specific gastrin-releasing peptide (GRP) antagonist, [D-F5, Phe6, D-Ala11]BN-(6-13) methyl ester (BN-ME), to block suppression of glucose intake (0.5 kcal/ml) produced by intraperitoneal administration of GRP-(18-27) in 5-h food-deprived male Sprague-Dawley rats (n = 10). We found that fourth ventricular administration of 10, 32, and 100 ng BN-ME blocked the suppression of glucose intake produced by peripherally administered 10 nmol/kg GRP-(18-27). The most effective dose of BN-ME (100 ng) blocked the ability of peripheral injection of GRP-(18-27) to inhibit glucose intake but had no effect on intake when given alone. These results demonstrate that the availability of caudal hindbrain GRP receptors is necessary for peripherally administered GRP-(18-27) to reduce food intake in rats.

scholarly journals Ethanol extract of Psoralea corylifolia L. and its main constituent, bakuchiol, reduce bone loss in ovariectomised Sprague–Dawley rats

2008 ◽  
Vol 101 (7) ◽  
pp. 1031-1039 ◽  
Author(s):  
Sun-Hye Lim ◽  
Tae-Youl Ha ◽  
Sung-Ran Kim ◽  
Jiyun Ahn ◽  
Hyun Jin Park ◽  
...  
Keyword(s):  
Bone Loss ◽  
Binding Affinity ◽  
Ethanol Extract ◽  
Treated Group ◽  
Vehicle Group ◽  
Psoralea Corylifolia ◽  
Sprague Dawley ◽  
Mineral Density ◽  
Sprague Dawley Rats

The aim of the present study was to investigate whether ethanol extracts of Psoralea corylifolia L. (PCE) and its active component protect against bone loss in ovariectomised rats. We screened oestrogenic activities of the main extract fractions using in vitro assays and identified bakuchiol as the most active oestrogenic component by HPLC and LC/MS, and then demonstrated that bakuchiol had strong binding affinity for oestrogen receptor (ER) α. Seventy female Sprague–Dawley rats were assigned to either a sham-operated group (n 10) or an ovariectomised group (n 60). The ovariectomised group was subdivided into six groups, each containing ten rats: vehicle group, two bakuchiol-treated groups (dose of 15 mg/kg per d or 30 mg/kg per d; ten rats for each group), two PCE-supplemented groups (0·25 % or 0·5 % extracts of diets; ten rats for each group) and a 17β-oestradiol (E2)-treated group (20 μg/kg per d). We recorded weight and feed intake every week, and killed all animals after 6 weeks. Blood was collected, and the uterus, kidneys and livers were removed. Bakuchiol has a three-fold higher binding affinity for ERα than for ERβ. Bakuchiol and PCE treatments had no uterotrophic activity even though they demonstrated oestrogenic activity in the in vitro assays. Bakuchiol and PCE treatments reduced postmenopausal bone loss by increasing alkaline phosphatase, Ca concentrations, serum E2 concentration and bone mineral density, and by decreasing the inorganic P level. The present study indicated that bakuchiol and PCE treatments could protect against bone loss.

scholarly journals Tissue Selectivity of the Anabolic Steroid, 19-Nor-4-Androstenediol-3β,17β-Diol in Male Sprague Dawley Rats: Selective Stimulation of Muscle Mass and Bone Mineral Density Relative to Prostate Mass

Endocrinology ◽  
2007 ◽  
Vol 149 (4) ◽  
pp. 1987-1993 ◽  
Author(s):  
Stephanie T. Page ◽  
Brett T. Marck ◽  
James M. Tolliver ◽  
Alvin M. Matsumoto
Keyword(s):  
Bone Mineral Density ◽  
Anabolic Steroids ◽  
Levator Ani ◽  
Levator Ani Muscle ◽  
Sprague Dawley ◽  
Mineral Density ◽  
Sprague Dawley Rats ◽  
Tissue Selectivity ◽  
Prostate Growth ◽  
Stimulation Of

Stimulation of prostate growth is a major concern with testosterone therapy in older hypogonadal men. As a result, nonsteroidal selective androgen receptor modulators with anabolic activity but less prostate stimulation are being developed. Anabolic steroids might exhibit similar tissue selectivity. We hypothesized the anabolic steroid 19-nor-4-androstenediol-3β,17β-diol (3β,19-NA) would increase muscle, lean body mass (LBM), and bone mineral density (BMD) with little stimulation of prostate growth. Male Sprague Dawley rats were implanted with SILASTIC brand (Dow Corning, Midland, MI) capsules containing 3β,19-NA (4, 8, or 16 cm), dihydrotestosterone (DHT) (8 cm), 19-nortestosterone (16 cm), or four empty capsules after undergoing either a sham operation (intact) or orchidectomy (ORX). Serum gonadotropins, measured after 4, 8, or 24 wk of treatment, were significantly lower in 3β,19-NA-treated vs. untreated, intact, and ORX rats (P < 0.05), and testosterone was lowered by 3β,19-NA-treatment of intact animals. LBM and BMD were assessed after 20 wk, and 4 wk later, rats were killed for levator ani muscle and prostate weights. Compared with ORX rats, 3β,19-NA-treated rats had dose-dependent higher levator ani muscle weights, LBM, and BMD, which were similar to intact and DHT-treated rats at the highest 3β,19-NA dose. In contrast, prostate weights in all 3β,19-NA-treated groups were similar to ORX rats and lower than intact and DHT- and 19-nortestosterone-treated rats even at the highest 3β,19-NA dose. In summary, 3β,19-NA increases muscle and bone mass without significant stimulation of prostate growth, suggesting it may have some properties of a steroidal selective androgen receptor modulator. Anabolic steroids such as 3β,19-NA should be studied further to determine their mechanisms of tissue selectivity and effects in men.

Homologous and cross-reacting antibodies in the sera of gnotobiotic rats

1978 ◽  
Vol 24 (4) ◽  
pp. 365-371 ◽  
Author(s):  
Joy C. McLeod ◽  
Edward Balish
Keyword(s):  
Gram Negative Bacteria ◽  
Sprague Dawley ◽  
Gram Positive ◽  
Passive Hemagglutination ◽  
Gram Negative ◽  
E Coli ◽  
Sprague Dawley Rats ◽  
Antibody Titers ◽  
The Relationship ◽  
Reactive Antibody

Sera from Sprague–Dawley rats monoassociated with Clostridium perfringens, C. tertium, C. bifermenlans, Staphylococcus aureus, Escherichia coli, Proteus mirabilis, or Klebsiella pneumoniae for 4 weeks were assayed for homologous and cross-reacting antibodies against antigens on a variety of bacteria. A passive hemagglutination assay, with the antigen(s) consisting of bacteria conjugated to tanned sheep red blood cells, was used to assess antibody titers. Both homologous and cross-reacting antibodies were detected in sera that were collected from the monoassociated animals. Sera from monoassociated rats had agglutinating antibody to genera of bacteria that had not colonized their gastrointestinal tract. Although S. aureus shared some antigens with three species of Clostridium, the relationship was not reciprocal. Sera from rats monoassociated with E. coli, P. mirabilis, or K. pneumoniae had cross-reactive antibody against gram-positive and gram-negative bacteria, but did not have antibodies that could agglutinate H. influenzae type b. Monoassociation with C. perfringens resulted in the production of antibodies against a variety of gram-positive and gram-negative bacteria, but it did not induce cross-reactive antibodies against Corynebacterium diphtheriae, streptococci (groups A, C, and G), or Staphylococcus epidennidis.

scholarly journals P0761STUDY ON THE MECHANISM OF MICROINFLAMMATION WITH UREMIA CAUSED BY LACTOBACILLUS ACTIVATION OF INTESTINAL MACROPHAGES BY MINCLE

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Lingshuang Sun
Keyword(s):  
Protein Expression ◽  
Sham Group ◽  
Intestinal Bacteria ◽  
Diabetic Patients ◽  
Sprague Dawley ◽  
Transmission Electron ◽  
Sprague Dawley Rats ◽  
Mrna And Protein Expression ◽  
End Stage ◽  
The Relationship

Abstract Background and Aims My previous studies have found that Intestinal macrophages in the uremic rats are polarized towards a proinflammatory phenotype and had dysfunction of phagocytosis leading to aggravate microinflammation and assist bacterial translocation in uremia resulting in microinflammation. However, it is still unclear what kind of mechanism of action of intestinal bacteria activates intestinal macrophages and thus participates in the occurrence and development of microinflammation in uremia. Method Male Sprague-Dawley rats were randomly divided into two groups: sham, uremia. The macrophage ultrastructure was examined by transmission electron microscopy. Immunochemistry was used to analyze the expression of macrophage-inducible C-type lectin (Mincle). RT-PCR and western blot were employed to assess the mRNA and protein expression of toll-like receptor 4 (TLR4). Results Our RCT study found that the number of Lactobacilli in the intestines of patients with end-stage diabetic nephropathy was significantly higher than that in non-diabetic patients(Figure 1). The plasma levels of endotoxin, CRP, IL-6, and TNF-a in the uremia group were greater than those in the sham group (p>0.05)(Table 1).Compared with the sham group, the uremic macrophages showed fewer cytoplasmic protrusions and pseudopodia(Figure 2) and the uremia group exhibited macrophages with higher staining intensities for Mincle and higher mRNA and protein expression of TLR4(Figure 3-5). Conclusion Studies have shown that Lactobacillus planta can directly activate Mincle. The relationship between Mincle and the activation of intestinal macrophages was verified. The solution to this scientific problem will not only clarify the molecular mechanism of intestinal bacteria in controlling the activation of intestinal macrophages, but also link the immune regulation of intestinal macrophages with the micro-inflammation of uremia so as to clarify the micro-inflammation state of uremia.

Regionally specific compensation for bone loss in the tibial trabeculae of estrogen-deficient rats

2007 ◽  
Vol 48 (5) ◽  
pp. 531-539 ◽  
Author(s):  
Z. F. Sheng ◽  
R. C. Dai ◽  
X. P. Wu ◽  
L. N. Fang ◽  
H. J. Fan ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Bone Loss ◽  
Bone Mineral ◽  
Estrogen Deficiency ◽  
Sprague Dawley ◽  
Micro Computed Tomography ◽  
Mineral Density ◽  
Trabecular Thickness ◽  
Sprague Dawley Rats ◽  
Rat Tibia

Background: Bone mineral density (BMD) and microstructural variations have been extensively investigated in recent years; however, the compensation for bone loss between different regions is still unclear. Purpose: To fully characterize regional variations in bone mineral density (BMD) as well as the microstructure and dynamic changes of rat tibial trabeculae that occur with bone loss associated with estrogen deficiency. Material and Methods: Female Sprague-Dawley rats were ovariectomized (OVX), sham-operated (sham), or left unoperated (baseline control). The left tibiae were harvested at baseline, and at postoperative weeks 3 and 15. High-resolution micro-computed tomography (µCT) was used to identify the densitometric and microstructural properties of trabeculae in the proximal ends of the rat tibia, specifically the epiphysis and metaphysis. Results: Volumetric BMDs at the organ (organ BMD) and tissue (tissue BMD) levels were significantly higher for trabeculae at the epiphysis than metaphysis. Moreover, trabeculae at the epiphysis were thicker, and fewer in number and connectivity than those at the metaphysis, which were more rod like. Trabeculae at the metaphysis were more susceptible to bone loss induced by estrogen deprivation than at the epiphysis, and the regions varied greatly in their adaptation to this loss. At the metaphysis, trabecular tissue BMD and thickness were unexpectedly higher at postoperative week 15 than week 3 or baseline. In contrast, at the epiphysis, tissue BMD did not change with time, but trabecular thickness significantly increased at week 15 compared to baseline and was also greater in OVX compared to sham rats. Conclusion: Metaphyseal and epiphyseal trabeculae show regionally specific variations in BMD and microstructure. The former are more susceptible to bone loss induced by estrogen deficiency and would be strengthened by either hypertrophy or hypermineralization, while epiphyseal trabeculae are mainly strengthened by thickening.

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