Resorption of Residual Ridges (RRR) in Rats

1987 ◽  
Vol 66 (12) ◽  
pp. 1753-1757 ◽  
Author(s):  
I. Nishimura ◽  
P.J. Damiani ◽  
D.A. Atwood

The post-extraction resorption of residual ridges (RRR) is a major and largely unsolved health problem, probably of multifactorial etiology. In order for one to study the role of specific factors in the pathophysiology of RRR, the use of animal models is desirable. The purpose of this study was to establish a reliable animal model and a standardized assay system to measure RRR for future experiments. A new oblique cephalometric device was designed to take pairs of xeroradiographs on the right and left sides of the rat skull and mandible at a 45-degree angle to the horizontal plane. Preliminary studies confirmed the reproducibility of the technique. All molars were extracted with minimal trauma from the right maxilla and mandible in five male Sprague-Dawley rats (40 days old). Longitudinal cephalographic examinations were performed before and immediately after extraction and at two, four, eight, and 12 weeks after extraction. Alveolar bone resorption was measured on enlarged cephalographs (5. 7X) at a point mesial to the mandibular first molar. Sequential mean bone resorption was 0.8 ± 0.2 mm (S.D.), 1.0 ± 0.3, 1.3 ± 0.3, and 1.5 ± 0.4, respectively. Graphically, these findings produced bone loss curves similar to those observed in man. These results indicate that the rat model may be utilized in longitudinal studies of the resorption of the residual ridge.

Author(s):  
B. J. Hurley ◽  
M. E. Cantino

Calcium is thought to play a major role in the activation of mammalian cardiac muscle. Several investigators have utilized Electron Probe X-ray Microanalysis (EPMA) to study the role of calcium in myocardial contraction. The purpose of this study is to measure subcellular elemental concentrations in rat papillary muscle under the influence of caffeine or elevated extracellular calcium. Of particular interest is the concentration of calcium in the junctional sarcoplasmic reticulum (jSR) under these conditions.Male Sprague-Dawley rats weighing approximately 300 g were anesthetized using I.P. Na-pentabarbitol injection. The hearts were carefully removed and back-perfused with a modified Tyrodes solution via cannulation of the aorta. The wall of the right ventricle was cut away revealing the papillary muscles. The tendon and wall ends of the papillary muscle were then sutured and the muscle was carefully cut out of the heart. The papillary muscle was then placed on the freezing device holder and the suture tied to a fixed post and tension transducer post, as shown in Figure 1.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
N. Hamzah ◽  
S. A. Aziz ◽  
A. R. Fauzi ◽  
Y. A. Mohd Yusof ◽  
M. Razali ◽  
...  

Gelam honey has been shown to exhibit antioxidant and anti-inflammatory activities in animal model. The aim of this study was to determine the effects of Gelam honey (Melaleuca cajuputi) on alveolar bone level in experimental periodontitis. Thirty male Sprague-Dawley rats were used in this study and randomly divided into four groups: ligated saline (LS), ligated honey (LH), nonligated saline (NLS), and nonligated honey (NLH). Fifteen days after supplementation with Gelam honey (3 g/kg), the rats were sacrificed and alveolar bone level was determined by radiography and histomorphometry. The number of osteoclasts was also calculated for all groups. Both radiographic and histomorphometric analyses showed that alveolar bone resorption was severely induced around the ligated molar in the LS and LH groups. There was no significant difference in alveolar bone level between the LS and LH groups. However, there was a nonsignificant reduction of osteoclast number by 15.2% in LH group compared to LS group. In the NLH group, there was less alveolar bone resorption and the number of osteoclasts was reduced by 13.2% compared to NLS group. In conclusion, systemically supplemented Gelam honey was shown to have the potential of reducing osteoclast activity in the experimental periodontitis rats, even though the effect on alveolar bone level was not well demonstrated and it warrants further research.


2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Rosanna Di Paola ◽  
Francesco Briguglio ◽  
Irene Paterniti ◽  
Emanuela Mazzon ◽  
Giacomo Oteri ◽  
...  

The aim of the present study was to evaluate the contribution of peroxisome proliferator-activated receptor (PPAR-β/δ) in animal model of periodontitis. Male Sprague-Dawley rats were lightly anaesthetized with pentobarbitone (35 mg/kg). Sterile, 2-0 black braided silk thread was placed around the cervix of the lower left first molar and knotted medially. Animals received GW0742 (0.3 mg/kg, 10% DMSO, i.p. after the ligature placement and daily for eight days). At day 8, the gingivomucosal tissue encircling the mandibular first molar was removed. One the eighth day after placement of the ligature, we evaluated (1) NF-κB expression, (2) cytokines expression, (3) iNOS expression, (5) the nitration of tyrosine, (6) apoptosis, and (8) the degree of gingivomucosal tissues injury. Administration of GW0742 significantly decreased all of the parameters of inflammation as described above. Taken together, these results demonstrate that GW0742 exerts an anti-inflammatory role during experimental periodontitis and is able to ameliorate the tissue damage.


2020 ◽  
Vol 53 (2) ◽  
pp. 76
Author(s):  
Ika Andriani ◽  
Edy Meiyanto ◽  
S. Suryono ◽  
Ika Dewi Ana

Background: Carbonate hydroxyapatite (CHA) is used as a scaffold to repair bone resorption. Alveolar bone resorption in periodontitis caused by an infection requires the presence of an antibacterial to support bone regeneration. Human β-defensin 3 (HBD3) is an antimicrobial peptide. The local application of the HBD3 antimicrobial is beneficial to inhibiting drug resistance and protecting tissue regeneration against invasive bacteria. Purpose: This study aims to investigate the effect of the administration of a combination of   CHA with HBD3 on the collagen density of periodontitis rats (Sprague Dawley). Methods: This study was a true experimental study with a post-test control group design. Thirty-two Sprague Dawley animal models were randomly blind selected placed under anaesthetic, then a 2-mm silk ligature was attached as a ligation to the mandibular incisors for 14 days in order to generate periodontitis. The study subjects were divided into two groups, the group with CHA and CHA loaded HBD3 (CHA + HBD3) implantation. On days 7, 14, 21 and 28, four rats were taken randomly from each group for decapitation, followed by histological processing and examination with trichome Mallory staining. The data was analysed using the Kruskal Wallis test (p<0.05). Results: An increase in collagen density during the healing process was found. There was a significant difference between CHA and CHA+HBD (p=0.004 and p=0.008; p<0.05) in collagen density between the groups. Conclusion: The combination of CHA and HBD3 can enhance the collagen density in periodontitis Sprague Dawley rats, compared to CHA only groups.


2014 ◽  
Vol 34 (6) ◽  
pp. 1070-1075 ◽  
Author(s):  
Chao Gao ◽  
Hanjian Du ◽  
Ya Hua ◽  
Richard F Keep ◽  
Jennifer Strahle ◽  
...  

Thrombin and iron are two major players in intracerebral hemorrhage-induced brain injury and our recent study found that thrombin contributes to hydrocephalus development in a rat model of intraventricular hemorrhage (IVH). This study investigated the role of red blood cell (RBC) lysis and iron in hydrocephalus after IVH. There were three parts to this study. First, male Sprague-Dawley rats received an injection of saline, packed, or lysed RBCs into the right lateral ventricle. Second, rats had an intraventricular injection of iron or saline. Third, the rats received intraventricular injection of lysed RBCs mixed with deferoxamine (0.5 mg in 5 μL saline) or saline. All rats underwent magnetic resonance imaging at 24 hours and were then euthanized for brain edema measurement, western blot analysis, or brain histology. We found that intraventricular injection of lysed RBCs, but not packed RBCs, resulted in ventricular enlargement and marked increases in brain heme oxygenase-1 and ferritin at 24 hours. Intraventricular injection of iron also resulted in ventricular enlargement and ventricular wall damage 24 hours later. Coinjection of deferoxamine reduced lysed RBC-induced ventricular enlargement ( P<0.01). These results suggest that iron, a degradation product of hemoglobin, has an important role in hydrocephalus development after IVH.


Author(s):  
Yun-Hee Kim ◽  
Sung-Uk Choi ◽  
Jung-Min Youn ◽  
Seung-Ha Cha ◽  
Hyeon-Ju Shin ◽  
...  

BACKGROUND: The prevention of rheologic alterations in erythrocytes may be important for reducing sepsis-associated morbidity and mortality. Remote ischemic preconditioning (RIPC) has been shown to prevent tissue damage caused by severe ischemia and mortality resulting from sepsis. However, the effect of RIPC on erythrocytes in sepsis is yet to be determined. OBJECTIVE: To investigate the effect of RIPC on rheologic alterations in erythrocytes in sepsis. METHODS: Thirty male Sprague-Dawley rats were used in this study. An endotoxin-induced sepsis model was established by intraperitoneally injecting 20 mg/kg LPS (LPS group). RIPC was induced in the right hind limb using a tourniquet, with three 10-minute of ischemia and 10 min of reperfusion cycles immediately before the injection of LPS (RIPC/LPS group) or phosphate-buffered saline (RIPC group). The aggregation index (AI), time to half-maximal aggregation (T1/2), and maximal elongation index (EImax) of the erythrocytes were measured 8 h after injection. RESULTS: The AI, T1/2, and EImax values in the LPS and RIPC/LPS groups differed significantly from those in the RIPC group, but there were no differences between the values in the LPS and RIPC/LPS groups. CONCLUSIONS: RIPC did not prevent rheologic alterations in erythrocytes in the rat model of LPS-induced endotoxemia.


2011 ◽  
Vol 300 (5) ◽  
pp. H1781-H1787 ◽  
Author(s):  
Sachin S. Kandlikar ◽  
Gregory D. Fink

Excess sympathetic nervous system activity (SNA) is linked to human essential and experimental hypertension. To test whether sympathetic activation is associated with a model of deoxycorticosterone acetate (DOCA)-salt hypertension featuring two kidneys and a moderate elevation of blood pressure, we measured whole body norepinephrine (NE) spillover as an index of global SNA. Studies were conducted in chronically catheterized male Sprague-Dawley rats drinking water containing 1% NaCl and 0.2% KCl. After a 7-day surgical recovery and a 3-day control period, a DOCA pellet (50 mg/kg) was implanted subcutaneously in one group of rats (DOCA), while the other group underwent sham implantation (Sham). NE spillover was measured on control day 2 and days 7 and 14 after DOCA administration or sham implantation. During the control period, mean arterial pressure (MAP) was similar in Sham and DOCA rats. MAP was significantly increased in the DOCA group compared with the Sham group after DOCA administration ( day 14: Sham = 109 ± 5.3, DOCA = 128 ± 3.6 mmHg). However, plasma NE concentration, clearance, and spillover were not different in the two groups at any time. To determine whether selective sympathetic activation to the kidneys contributes to hypertension development, additional studies were performed in renal denervated (RDX) and sham-denervated (Sham-DX) rats. MAP, measured by radiotelemetry, was similar in both groups during the control and DOCA treatment periods. In conclusion, global SNA is not increased during the development of mild DOCA-salt hypertension, and fully intact renal nerves are not essential for hypertension development in this model.


1994 ◽  
Vol 267 (2) ◽  
pp. H751-H756 ◽  
Author(s):  
A. W. Cowley ◽  
E. Szczepanska-Sadowska ◽  
K. Stepniakowski ◽  
D. Mattson

Despite the well-recognized vasoconstrictor and fluid-retaining actions of vasopressin, prolonged administration of arginine vasopressin (AVP) to normal animals or humans fails to produce sustained hypertension. The present study was performed to elucidate the role of the V1 receptor in determining the ability of AVP to produce sustained hypertension. Conscious Sprague-Dawley rats with implanted catheters were infused with the selective V1 agonist, [Phe2,Ile3,Orn8]vasopressin (2 ng.kg-1.min-1), for 14 days in amounts that were acutely nonpressor. Blood pressure (MAP), heart rate (HR), body weight, and water intake (WI) were determined daily. Plasma AVP, plasma catecholamines norepinephrine and epinephrine, plasma osmolality, and electrolyte concentration were determined before and on days 1 and 7 of infusion. MAP increased significantly by 10.4 +/- 4.5 mmHg on day 1 and rose to 22 +/- 5 mmHg above control by day 14 (transient decrease on days 6-9) and then fell to control levels after the infusion was stopped. HR did not change significantly. Plasma AVP immunoreactivity increased from 2.5 +/- 0.3 to 10.9 +/- 2.1 pg/ml, whereas norepinephrine tended to fall only on day 1, with epinephrine only slightly elevated on day 7. No evidence of fluid retention was found, and rats lost sodium only on the first day of V1 agonist infusion. Body weight increased throughout the study but was unrelated to the changes of MAP. We conclude that chronic stimulation of V1 receptors results in sustained hypertension in rats.


2021 ◽  
Vol 17 ◽  
Author(s):  
Gideon Ayeni ◽  
Mthokozisi Blessing Cedric Simelane ◽  
Shahidul Islam ◽  
Ofentse Jacob Pooe

Background: Medicinal plants together with their isolated bioactive compounds are known for their antioxidant properties which constitute therapeutic agents that are routinely employed in the treatment of liver diseases. Aims of the Study: The current study sought to explore the protective role of Warburgia salutaris and its isolated compound, iso-mukaadial acetate against carbon tetrachloride (CCl4)-induced hepatic injury. Methods: Thirty-five male Sprague Dawley rats were divided into seven groups of five animals each and injected with CCl4 to induce hepatic injury. Results: Treatment with the crude extract of W. salutaris and of iso-mukaadial acetate significantly reduced the levels of alkaline phosphatase, alanine and aspartate aminotransaminases, total bilirubin and malondialdehyde in a dose dependent manner, when compared to untreated groups. Liver histology revealed a reduction in hepatic necrosis and inflammation. Conclusion: The current investigation has demonstrated that W. salutaris extract and iso-mukaadial acetate could mitigate the acute liver injury inflicted by a hepatotoxic inducer in rats.


2006 ◽  
Vol 74 (7) ◽  
pp. 4387-4389 ◽  
Author(s):  
Rachel Marion ◽  
Asiya Baishanbo ◽  
Gilles Gargala ◽  
Arnaud François ◽  
Philippe Ducrotté ◽  
...  

ABSTRACT In 5-day-old immunocompetent Sprague-Dawley rats infected with either 102 or 105 Cryptosporidium parvum oocysts, transient infection resulted 120 days later in increased cardiovascular depressor response to jejunal distension and jejunal myeloperoxidase activity (P < 0.05). Nitazoxanide treatment normalized jejunal sensitivity (P < 0.001) but not myeloperoxidase levels (P > 0.05). Data warrant further evaluation of the role of early cryptosporidiosis in the development of chronic inflammatory gut conditions.


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