A model for demonstration of reversal of impairment of endothelium-dependent relaxation in the cholesterol-fed rabbit

1990 ◽  
Vol 68 (7) ◽  
pp. 845-850 ◽  
Author(s):  
C. Tissa Kappagoda ◽  
Alan B. R. Thomson ◽  
Manohara P. J. Senaratne

This investigation was undertaken to determine whether it was possible to restore endothelium-dependent relaxation (EDR) in the cholesterol-fed rabbit model of atherosclerosis following discontinuation of the cholesterol. New Zealand white rabbits, approximately 8 weeks of age, were randomized into (i) control group (9 animals fed a standard rabbit diet) and (ii) experimental group (27 animals: fed the same diet supplemented with 2.5% cholesterol). The experimental animals were restored to the standard diet after 3 weeks. EDR to acetylcholine (−9.0 to −5.0 log mol/L) was examined in the experimental animals at 3, 7, and 15 weeks after commencement of the study (n = 9 at each stage) and the nine control animals examined after 7 weeks. At the end of 7 weeks, EDR to acetylcholine (−6.0 log mol/L) was significantly (p < 0.05) impaired in the experimental group (34.3 ± 3.8%) compared with that in the control group (79.8 ± 3.0%). The loss of EDR was not apparent in the experimental group at 3 weeks (relaxation: 81.7 ± 4.7%). At the end of 15 weeks, the EDR was significantly restored in the experimental group (relaxation: 63.6 ± 5.1%). These findings demonstrate that it is possible to reverse the loss of EDR that occurs with cholesterol feeding in the rabbit by limiting the period of exposure to a high cholesterol diet.Key words: atherosclerosis, endothelium-dependent relaxation, rabbit aorta, regression.

1989 ◽  
Vol 67 (11) ◽  
pp. 1454-1460 ◽  
Author(s):  
Laal Jayakody ◽  
Manohara P. J. Senaratne ◽  
Alan B. R. Thomson ◽  
Nadarajan Sreeharan ◽  
C. Tissa Kappagoda

The synthesis and (or) release of endothelium-dependent relaxant factor released by acetylcholine is impaired in New Zealand white rabbits fed an atherogenic diet. Experiments were designed to investigate whether the synthesis and (or) release of the endothelium-dependent relaxant factor from rabbit aortas are restored after reversal from an atherogenic diet to a non-atherogenic diet. Atherosclerosis was induced by feeding a diet containing lipids and 2% cholesterol for 6 weeks. Rabbits were sacrificed after 6 weeks on the atherogenic diet and 36 weeks after return to a standard laboratory diet. Synthesis and (or) release of the factor from the thoracic aorta was assayed using a bioassay system. The relaxant responses produced in the assay tissue were impaired both in the acute stage and after 36 weeks on non-atherogenic food. This impaired relaxation is probably due to a persistent functional abnormality in the aortic endothelium resulting in the failure to synthesize and (or) release endothelium-dependent relaxation factor 36 weeks after induction of atherosclerosis.Key words: endothelium dependent relaxation, rabbit aorta, atherosclerosis, regression, cholesterol feeding.


1985 ◽  
Vol 63 (9) ◽  
pp. 1206-1209 ◽  
Author(s):  
R. L. Jayakody ◽  
M. P. J. Senaratne ◽  
A. B. R. Thomson ◽  
C. T. Kappagoda

Experiments were designed to assess the effect of cholesterol feeding on the endothelium-mediated relaxation of the rabbit aorta to acetylcholine. Age-matched male New Zealand white rabbits were fed either a 2% cholesterol diet or standard rabbit chow. The animals were anaesthetized with sodium pentobarbitone and sacrificed after 4 and 8 weeks on these diets. Rings were prepared from the proximal thoracic aorta and examined in tissue baths. These rings were contracted first with norepinephrine (−6 log mol/L) and acetylcholine was added to demonstrate the endothelium-mediated relaxation. The endothelium-dependent relaxation was significantly less in aortas from rabbits fed the 2% cholesterol diet than in aortas from animals fed the conventional diet. This impairment of relaxation was apparent after both 4 and 8 weeks of cholesterol feeding. In both groups of animals no relaxation was seen in rings from which the endothelium was removed. These results show that cholesterol feeding leads to an impairment of endothelium-mediated relaxation of the rabbit aorta to acetylcholine.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Ufuk Tatli ◽  
Yakup Üstün ◽  
Mehmet Kürkçü ◽  
Mehmet Emre Benlidayı

Objective. The purpose of the present study is to evaluate the effects of systemically administered zoledronic acid (ZA) on the physiological bone remodeling and the microarchitectural parameters of the condylar part of TMJ in a rabbit model.Study Design. Thirty skeletally mature male New Zealand white rabbits were randomly divided into two groups. The experimental group was administered an intravenous, single dose of 0.1 mg/kg ZA diluted with 15 mL of saline in a 15-minute perfusion with an infusion pump. The control group was administered only saline infusion for 15 minutes. All rabbits were sacrificed on the 21st postoperative day. Radiodensitometric and histomorphometric examinations were performed on the harvested mandibular condyles. The data were analyzed statistically.Results. Radiodensitometric findings showed that ZA treatment resulted in a significant increase in the mineralization of mandibular condyle. This result was supported by the histomorphometric findings.Conclusion. The present study has revealed that a temporary delay in the physiological bone remodeling using single dose of ZA increases bone mineral content and makes the microarchitecture of the mandibular condyle more compact. These effects may be regarded as base data and considered in numerous clinical situations including TMJ.


2020 ◽  
pp. 15-18
Author(s):  
Inna R. Kilmetova ◽  
◽  
Igor A. Rodin ◽  
Nazira I. Khayrullina ◽  
Nikolay G. Fenchenko ◽  
...  

Summary. The disbalanced feeding and the uneven distribution of micro- and macroelements in the environment leads to a trace element, in particular hypomelanosis. To accelerate the growth and preservation of young farm animals include in the diet of various biological additives and drugs, which include selenium. For stimulation of weight gain in the livestock industry, as well as for the prevention and treatment of pathological processes in addition to micro - and macrouse amino acids, primarily methionine. The aim of this work was to study the influence of composition of DAFS-25+Polizon on morpho-biochemical parameters of blood and functional state of the liver in fattening bulls of black-motley breed in the conditions of the Republic of Bashkortostan. Experiments using were conducted on bull-calves of black-motley breed of the properties in the properties age from 6 to 15 months. The first experimental group during the experiment was additionally given the composition of DAFS-25+Polizon at a dose of 2 mg/kg, the animals of the control group received a standard diet. To assess the impact of the composition DAFS-25+Polizon on metabolism cattle studied morphological and biochemical indicators of blood and conducted histological examination of the liver. It is established that the use of the composition of DAFS-25+Polizon at a dose of 2 mg/kg increases the number of erythrocytes and hemoglobin in the experimental group and reduces the amount of white blood cells. The serum content of total protein, phosphorus and calcium increases in the group of experimental animals. Microscopic examination of the liver revealed no changes in the structure of the organ and hepatocytes in the experimental group, whereas in the control group hemodynamic disorders and dystrophic changes in liver cells were observed. Thus, the use of the composition DAFS-25+Polizon at a dose of 2 mg/kg of live weight in fattening bulls black-and-white breed contributes to the increase of redox processes in the body, stimulation of metabolism, prevent the development of liver disorders of cellular mechanisms of metabolism, optimizes the structure of the liver, which generally provides higher productivity.


2021 ◽  
pp. 153537022110271
Author(s):  
Yuanyuan Jia ◽  
Liuqin Xie ◽  
Zhenglong Tang ◽  
Dongxiang Wang ◽  
Yun Hu ◽  
...  

After high fractures of the mandibular condyle, the insufficient blood supply to the condyle often leads to poor bone and cartilage repair ability and poor clinical outcome. Parathyroid hormone (PTH) can promote the bone formation and mineralization of mandibular fracture, but its effects on cartilage healing after the free reduction and internal fixation of high fractures of the mandibular condyle are unknown. In this study, a rabbit model of free reduction and internal fixation of high fractures of the mandibular condyle was established, and the effects and mechanisms of PTH on condylar cartilage healing were explored. Forty-eight specific-pathogen-free (SPF) grade rabbits were randomly divided into two groups. In the experimental group, PTH was injected subcutaneously at 20 µg/kg (PTH (1–34)) every other day, and in the control group, PTH was replaced with 1 ml saline. The healing cartilages were assessed at postoperative days 7, 14, 21, and 28. Observation of gross specimens, hematoxylin eosin staining and Safranin O/fast green staining found that every-other-day subcutaneous injection of PTH at 20 µg/kg promoted healing of condylar cartilage and subchondral osteogenesis in the fracture site. Immunohistochemistry and polymerase chain reaction showed that PTH significantly upregulated the chondrogenic genes Sox9 and Col2a1 in the cartilage fracture site within 7–21 postoperative days in the experimental group than those in the control group, while it downregulated the cartilage inflammation gene matrix metalloproteinase-13 and chondrocyte terminal differentiation gene ColX. In summary, exogenous PTH can stimulate the formation of cartilage matrix by triggering Sox9 expression at the early stage of cartilage healing, and it provides a potential therapeutic protocol for high fractures of the mandibular condyle.


2017 ◽  
Vol 45 (9) ◽  
pp. 2019-2027 ◽  
Author(s):  
Dong-Sam Suh ◽  
Jun-Keun Lee ◽  
Ji-Chul Yoo ◽  
Sang-Hun Woo ◽  
Ga-Ram Kim ◽  
...  

Background: Failure of rotator cuff healing is a common complication despite the rapid development of surgical repair techniques for the torn rotator cuff. Purpose: To verify the effect of atelocollagen on tendon-to-bone healing in the rabbit supraspinatus tendon compared with conventional cuff repair. Study Design: Controlled laboratory study. Methods: A tear of the supraspinatus tendon was created and repaired in 46 New Zealand White rabbits. They were then randomly allocated into 2 groups (23 rabbits per group; 15 for histological and 8 for biomechanical test). In the experimental group, patch-type atelocollagen was implanted between bone and tendon during repair; in the control group, the torn tendon was repaired without atelocollagen. Each opposite shoulder served as a sham (tendon was exposed only). Histological evaluation was performed at 4, 8, and 12 weeks. Biomechanical tensile strength was tested 12 weeks after surgery. Results: Histological evaluation scores of the experimental group (4.0 ± 1.0) were significantly superior to those of the control group (7.7 ± 2.7) at 12 weeks ( P = .005). The load to failure was significantly higher in the experimental group (51.4 ± 3.9 N) than in the control group (36.4 ± 5.9 N) ( P = .001). Conclusion: Histological and biomechanical studies demonstrated better results in the experimental group using atelocollagen in a rabbit model of the supraspinatus tendon tear. Clinical Relevance: Atelocollagen patch could be used in the cuff repair site to enhance healing.


1997 ◽  
Vol 273 (2) ◽  
pp. H647-H654 ◽  
Author(s):  
M. Cappelli-Bigazzi ◽  
S. Rubattu ◽  
C. Battaglia ◽  
R. Russo ◽  
I. Enea ◽  
...  

Hypercholesterolemia is associated with more rapid development of atherosclerosis, and hypertension is frequently associated with abnormal vascular function. Therefore, to investigate the role of hypercholesterolemia and hypertension on vascular function, we studied three groups of male rats (aged 6 wk): normotensive Wistar-Kyoto rats (WKY) as a control group and spontaneously hypertensive rats (SHR) receiving either standard diet (SD; SHR-SD) or high-cholesterol (1%) diet (ChD; SHR-ChD). Vascular reactivity was tested on isolated aortic rings at 4 wk and at 3 and 6 mo of diet. At 3 mo, endothelium-dependent relaxation to acetylcholine (ACh) and ADP was significantly reduced in SHR-ChD but not in SHR-SD compared with WKY. At 6 mo, relaxations to ACh were further impaired in both SHR groups compared with WKY. Endothelium-independent vasodilation to nitroglycerin (NTG) was not different in the three groups of animals throughout 6 mo of diet. In additional experiments, we evaluated vascular reactivity in rats fed with ChD enriched with an excess of vitamin D [atherogenic diet (AD)] capable of producing vascular atherosclerotic lesions. In particular, we studied three additional groups of WKY and SHR rats fed with SD, AD, or AD plus a nonhypotensive dose of the calcium antagonist nitrendipine (Nit). Vasodilation to ACh and ADP was significantly blunted in WKY-AD compared with WKY-SD, whereas it was partially improved in WKY-Nit. There were no differences in endothelium-independent relaxation to NTG in the three WKY groups. In contrast, SHR-AD showed a marked reduction of endothelium-dependent and -independent vasodilation, but only endothelium-dependent vasodilation was preserved by addition of Nit to the diet. These data suggest that the development of vascular dysfunction in rat genetic hypertension is accelerated by ChD, in absence of detectable vascular lesions. Our study also shows that AD alters both vascular smooth muscle and endothelium-dependent relaxation. Low doses of Nit partially preserve endothelium-dependent vasodilation but do not affect the impairment of smooth muscle function in these rats.


2017 ◽  
Vol 19 (74) ◽  
pp. 123-126
Author(s):  
N. B. Seba ◽  
M. A. Khomenko

In this paper present the results of research of influence of the preparation «Kvatronan-Se» and carboxylates of Se, Cu, Mn, Cr, Ge in different combinations on haematological parameters of blood of experimental animals. Study was carried out on the basis of PC Haleks-Agro. It is located in the village Gul'sk of Novograd Volynskiy district of Zhytomyr region. In the farm to bred of Simmental cows. For the experiment was formed four groups. We took into account age, live weight of 650–700 kg and the average milk yield 5000–6000 kg. Animals is located in identical conditions of feeding and maintenance. Research experiment was carried out on animals couples counterparts.  Preparations introduced animals three times at 10–12 days after insemination. The cows first experimental group were injected complex nanokarboksylativ Ge, Cu, Mn and Cr, second – drug Kvatronan–Se and animals third experimental group was administered a complex composed of Se, Cu, Mn, Cr. On 13 day after insemination in experimental animals were taken blood from tail vein and examined the contents of hematological parameters. Established that injection nanokarboksylativ enhance the fertility of cows in the first and third group, the figure rose to 20% in the second by 40% compared with the control. Research hematological parameters blood  animals shows that after entering content drugs of blood cells had minor changes but remained within the physiological norm. The results show that in  concentration monocyte the second group  was at 5.53% (P > 0.01) higher compared to the control group and 2.3% compared to the first and third. The content of lymphocytes in this group decreased by 26.3% (P > 0.05), 22% and 16% relative to the control, the first and third groups. Also, it should be noted that the hemoglobin in the experimental groups decreased in group I by 7.9% in the II – 3.9% and III by 7.3% compared with the control group. Also, these groups distinguished downward trend eosinophils 1.8%, 1.5%, 2.05%. Then, as the number of segment-nuclear neutrophils contrast, in the first group increased by 18.2% in the second and third at 16.9% comparatively control. The number of monocytes in the second group doslfidniy the suspicion was higher by 66.3% and 0.3% higher than the physiological norm – it may indicate a high immune response.


Author(s):  
Е.П. ВИКТОРОВА ◽  
Е.В. ЛИСОВАЯ ◽  
М.В. ЛУКЬЯНЕНКО ◽  
Н.Н. КОРНЕН ◽  
Е.В. КУЗЬМИНОВА ◽  
...  

Для получения препаратов и добавок, обладающих антиоксидантными свойствами, представляют интерес выжимки томатов, образующиеся при производстве сока прямого отжима с предварительным отделением семян. Проведена сравнительная оценка эффективности функциональных свойств образцов пищевой добавки, полученных из выжимок томатов по различным технологиям: образец добавки 1 получен по технологии, включающей ИК-сушку выжимок, их охлаждение и измельчение; образец добавки 2 – по инновационной технологии, включающей дополнительную предварительную обработку выжимок в ЭМП СВЧ перед ИК-сушкой. Исследования проводили в течение 30 дней на трех группах лабораторных белых крыс: контрольной, животные которой получали стандартный рацион, и двух опытных, в которых животные помимо основного рациона получали при кормлении индивидуально 1 раз в сутки 2 г добавки образца 1 (1-я опытная группа) или образца 2 (2-я опытная группа). Установлено, что степень снижения концентрации ферментов печени АсАт и АлАт в крови животных 2-й опытной группы соответственно на 10,6 и 11,0% выше, чем в крови животных 1-й опытной группы. Степень снижения содержания диеновых коньюгатов, кетодиенов и малонового диальдегида в крови животных 2-й опытной группы была соответственно на 22,1; 10,1 и 12,7% выше по сравнению с аналогичными показателями животных 1-й опытной группы. Таким образом, доказано, что пищевая добавка «Томатная», выработанная по инновационной технологии, проявляет ярко выраженные антиоксидантные и гепатопротекторные свойства, что обеспечивает нормализацию биохимических процессов в организме, повышает его антиоксидантную защиту и препятствует разрушению мембран клеток. For the obtaining of preparations and additives with antioxidant properties, tomato pomace, formed during the production of direct-pressed juice with preliminary separation of seeds, is of interest. A comparative evaluation of the effectiveness of the functional properties of food additive samples obtained from tomato pomace using various technologies was carried out. The sample of additive 1 was obtained using a technology that includes IR drying of pomace, cooling and grinding; the sample of additive 2 was obtained using a technology that includes additional pretreatment of pomace in microwave EMF before IR drying. The studies were carried out for 30 days on three groups of laboratory white rats: a control group, the animals of which were given a standard diet, and two experimental ones, in which the animals, in addition to the main diet, were given individually once a day with 2 g of an additive of sample 1 (1st experimental group) or sample 2 (2nd experimental group). It was found that the degree of decrease in the concentration of liver enzymes AsAt and AlAt in the blood of animals of the 2nd experimental group was respectively 10,6 and 11,0% higher, than in the blood of animals of the 1st experimental group. The degree of decrease in the content of diene conjugates, ketodienes and malondialdehyde in the blood of animals of the 2nd experimental group was higher respectively by 22,1; 10,1 and 12,7% compared with similar indicators of animals of the 1st experimental group. Thus, it is proved that the food additive «Tomatnaya», developed by innovative technology, shows pronounced antioxidant and hepatoprotective properties, which ensures the normalization of biochemical processes in the body, increases its antioxidant protection and prevents the destruction of cell membranes.


2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Ilkka Saarenpää ◽  
Patricia Stoor ◽  
Janek Frantzén

AbstractBioactive glass (BAG) S53P4 granules represent a bone augmentation biomaterial for the surgical treatment of bony defects, even in challenging conditions such as osteomyelitis. The aim of this eight-week rabbit implantation study was to evaluate the biocompatibility and bone regeneration performance of a BAG S53P4 putty formulation following its implantation into the proximal tibia bone of twenty-eight New Zealand white rabbits. BAG S53P4 putty was compared to BAG S53P4 granules (0.5-0.8 mm) to evaluate whether the synthetic putty binder influences the bone regeneration of the osteostimulative granules. The putty formulation facilitates clinical use because of its mouldability, injectability and ease of mixing with autograft. Implantation of putty and granules into proximal tibia defects resulted in good osseointegration of the two groups. Both biomaterials were biocompatible, showed high new bone formation, high vascularization and periosteal growth. No signs of disturbed bone formation were observed due to the PEG-glycerol binder in the BAG S53P4 putty. Instead, intramedullary ossification and stromal cell reaction were more advanced in the putty group compared to the control group (p = 0.001 and p < 0.001). In conclusion, the novel mouldable BAG S53P4 putty showed reliable bone regeneration in bony defects without adverse tissue or cell reactions.


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