Fourteen three-month-old rabbits spontaneously-infected with the microsporidium Encephalilozoon cuniculi Levaditi, Nicolau et Schoen, 1923 were inoculated intravenously with lymphocytes (Ly) from seropositive bovine leukemia virus infected cattle (Ly/BLV) or with fetal lamb kidney cells infected with bovine fetal leukemia (FLK/BLV). Thirteen rabbits were seropositive to BLV at least for a period of three months. Six rabbits died of pulmonary lesions. Chronic inflammatory lesions of ence-phalitozoonosis were found in six rabbits killed between 454 and 548 days of the observation period. Five animals bore subcutaneous granulomas. Immunohistochemically, E. cuniculi was demonstrated in the inflammatory lesions of rabbits studied. Control animals also spontaneously infected with E. cuniculi did not show clinical signs of encephalitozoonosis. Morphological changes were found incidentally in the form of small glial foci and focal interstitial nephritis in these animals. The combined action of BLV - E. cuniculi on the bodies of rabbits is proposed as a suitable model for the study of encephalitozoonosis in man with human immunodeficiency virus (HIV) infection.
The latest research reveals that nitric oxide as a gas messenger may diffuse into the surrounding extracellular fluid and act locally upon neighboring target cells. However, several observations raise the possibility that nitric oxide may also be released at a greater distance from the neuronal cell body. The catalytic nitric oxide synthase (cNOS) activity was therefore studied in the cervicothoracic and lumbosacral segments of the spinal cord of rabbits, including the white matter of dorsal columns (DC), lateral columns (LC) and ventral columns (VC), as well as the gray matter of dorsal horns (DH), intermediate zone (IZ) and ventral horns (VH). Lower cNOS activity was found in the white matter of both cervicothoracic (47 %) and lumbosacral (30 %) regions, whereas that detected in the gray matter of the lumbosacral part of the spinal cord was considerably higher (70 %). Enzyme activity varied from 43.4 to 77.2 dpm/µg protein in the cervicothoracic segments of the gray matter in the descending order: DH>VH>IZ. Similar cNOS activity was found in the white matter of the cervicothoracic segments (42.1-62.8 dpm/µg protein). When the activity of cNOS was compared in the lumbosacral segments, the highest enzyme activity was found in DH of the gray matter (198.7 dpm/µg protein) and the lowest cNOS in DC (45.8 dpm/µg protein) of the white matter. It was concluded that the white matter of the spinal cord contains similar cNOS activity in comparison to the gray matter., N. Lukáčová, J. Pavel., and Obsahuje bibliografii
Angiotensin converting enzyme inhibitors are widely used in therapy of cardiovascular diseas es. However, the consensus on effects of these inhibitors in control of myocardial oxygen consumption during the process of experimental hypercholesterolemia and under the condition of endothelial dysfunction has not been reached. Here we examined effects of captopril, an angiotensin converting enzyme inhibitor, on serum lipid levels and oxygen consumption rate in mitochondria isolated from heart of rabbits treated by hypercholesterolemic diet. During the twelve-week period, th e Chinchilla male rabbits were daily treated by saline (controls); 1 % cholesterol diet; 5 mg/kg/day captopril or 1 % cholesterol + 5 mg/kg/day captopril. Total- and high-densi ty lipoprotein cholesterol and triglyceride in serum were measured spectrophotometricly. The left ventricle mitochondrial fraction was isolated and myocardial oxygen consumption was measur ed by Biological Oxygen Monitor. Mitochondria isolated from hearts of rabbits exposed to hypercholesterolemic diet sh owed significantly reduced respiration rates (state 3 and state 4) with altering adenosine diphosphate/oxygen ratio, whereas the respiratory control ratio was not affected when compared to controls. Mitochondria from cholesterol/captopril-treated animals showed significantly reduced respiration rates without altering adenosine diphosphate/oxygen ratio index or respiratory control ratio. Although captopril did not exert the favorable effect on serum lipid levels in cholesterol-treated animals, it restored the mitochondrial oxygen consumption. Further studies should be performed to define the under lying physiological and/or pathophysiological mechanisms and clinical implications., Z. Kojic ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Hippocampus is a brain structure containing vasopressin (AVP) fibers and specific binding sites for this peptide. There is growing evidence that AVP and its metabolites participate in glutamate-mediated plasticity of the hippocampus. The aim of the present study was to evaluate the influence of NMDA on AVP release in the rabbit hippocampus. Caudate nucleus was chosen as the reference structure. The mentioned brain structures were simultaneously microdialyzed with 0.9 % NaCl solution. AVP was determined in the outflowing fluid by radioimmunoassay. The mean basal AVP content in the fluid outflowing from the hippocampus was significantly greater than that from the caudate nucleus. The addition of K+ into the fluid perfusing the probes implanted into the hippocampus and caudate nucleus significantly increased AVP release into the extracellular fluid of both brain structures. NMDA applied into the mentioned brain structures increased AVP release only from the hippocampus but not from the caudate nucleus. Our findings indicate a role which NMDA receptors play in AVP release into the extracellular fluid of the hippocampus., M. Orłowska-Majdak, W. Z. Traczyk, D. Szymański., and Obsahuje bibliografii
A ssessment of the cerebral microcirculation by on-line visualization has been impossible for a long time. Sidestream dark-field (SDF) imaging is a relatively new method allowing direct visualization of cerebral surface layer microcirculation using hand-held probe for direct contact with target tissue. The aim of this study was to elucidate the feasibility of studying the cerebral microcirculation in situ by SDF imaging and to assess the basic cerebral microcirculatory parameters in mechanically ventilated rabbits. Images were obtained using SDF imaging from the surface of the brain via cranio tomy. Clear high contrast SDF images were successfully obtained. Total small-vessel density was 14.6±1.8 mm/mm 2 , total all-vessel density was 17.9±1.7 mm/mm2, DeBacker score was 12.0±1.6 mm-1 and microvascular flow index was 3.0±0.0. This method seems to be applicable in animal studies with possibility to use SDF imaging also intraoperatively, providing unique opportunity to study cerebral microcirculation during various ex perimental and clinical settings., M. Šitina ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Oxygen supply was corrected in rabbits during the hepatic ischemia/reperfusion by means of different breathing mixtures: hypoxic (14.8 % O2+85.2 % N2), hyperoxic (78 % O2+20.2 % N2+ 1.8 % CO2), or hypercapnic (5 % CO2 in air). Hepatic ischemia was induced for 30 min by ligation of hepatic artery, reperfusion period lasted 120 min. Indices of blood oxygen transport (p50act, pCO2, pH, pO2, etc.) and prooxidant-antioxidant balance (Schiff bases, conjugated dienes, catalase, retinol, a-tocopherol) were measured in the blood and liver. The severity of reperfusion damage was evaluated by the activities of alanine and aspartate aminotransferases (ALT, AST) in the blood. Hepatic ischemia/reperfusion resulted in higher p50act in hepatic venous and mixed venous blood in all experimental groups. The changes of p50act were most marked in the hypercapnic group and were the weakest in the hypoxic group. The rise in p50act was accompanied by higher levels of lipid peroxidation products, ALT and AST in blood and liver homogenates, and by a simultaneous fall of α-tocopherol and retinol concentrations, except in the hypoxic group. Catalase activity at the end of reperfusion increased under normoxia, decreased under hyperoxia or hypercapnia and did not change under hypoxia. The moderate hypoxia during reperfusion was accompanied by a better balance between the mechanisms of reactive oxygen species production and inactivation that may be observed by optimal changes in p50act and reduced the hepatic damage in this pathological condition., V. V. Zinchuk, M. N. Khodosovsky, D. A. Maslakov., and Obsahuje bibliografii
We used a model of tibial lengthening in rabbits to study the postoperative pain pattern during limb-lengthening and morphological changes in the dorsal root ganglia (DRG), including alteration of substance P (SP) expression. Four groups of animals (naïve; OG: osteotomized only group; SDG/FDG: slow/fast distraction groups, with 1 mm/3 mm lengthening a day, respectively) were used. Signs of increasing postoperative pain were detected until the 10th postoperative day in OG/SDG/FDG, then they decreased in OG but remained higher in SDG/FDG until the distraction finished, suggesting that the pain response is based mainly on surgical trauma until the 10th day, while the lengthening extended its duration and increased its intensity. The only morphological change observed in the DRGs was the presence of large vacuoles in some large neurons of OG/SDG/FDG. Cell size analysis of the S1 DRGs showed no cell loss in any of the three groups; a significant increase in the number of SP-positive large DRG cells in the OG; and a significant decrease in the number of SP-immunoreactive small DRG neurons in the SDG/FDG. Faster and larger distraction resulted in more severe signs of pain sensation, and further reduced the number of SP-positive small cells, compared to slow distraction., K. Pap, Á. Berta, G. Szöke, M. Dunay, T. Németh, K. Hornok, L. Marosföi, M. Réthelyi, M. Kozsurek, Z. Puskár., and Obsahuje bibliografii
An organ-preserving solution, including in its composition also organic molecules, prepared at the University of Wisconsin (UW), has been successfully used for preservation of liver, pancreas and kidney, and has recently been tested for long-term storage of isolated hearts. We have compared the effectiveness of the UW solution with that of a standard crystalloid cardioplegic solution (St. Thomas, ST) in the functional and structural preservation of isolated hearts. The hearts taken from 24 rabbits were mounted on a Langendorff preparation. After assessment of the left ventricular function by an intraventricular balloon, 40 ml of either cardioplegic solution were injected to arrest the hearts (12 UW and 12 ST), which were then immersed in the same solution for 4 h at 4 °C without perfusion. After this period, the hearts were normothermally reperfused with oxygenated Krebs-Henseleit solution for 30 min, and finally left ventricular function was assessed again. An electron microscopic evaluation was performed as well. Significantly higher recovery of left ventricular developed pressure (p<0.01) and of negative dP/dt (p<0.05), was observed after preservation with UW, while no difference on positive dP/dt was found. After reperfusion, left ventricular end-diastolic pressure significantly rose with ST (p<0.01), but did not change with UW; the difference between ST and UW was significant (p<0.01). Tissue water content was significantly lower in the hearts preserved with UW (p<0.05). Electron microscopic examination revealed generally good preservation with no substantial difference between the two solutions. We conclude that UW cardioplegic solution, rather than ST solution, associated with low temperature, provides better protection of isolated hearts against ischaemia and reperfusion injury after long-term preservation. This is probably due to the combined effects of antioxidants, cell- membrane impermeable substances and oncotic agents.
Species of Blastocystis Alexieff, 1911 are anaerobic intestinal protists found in humans and many kinds of animals that mainly cause diarrhea, abdominal pain and other clinical symptoms. At present, data on the prevalence and subtype diversity of species of Blastocystis in domestic rabbits are very limited. The purpose of this study was to characterise the infection rate and gene subtype distribution of Blastocystis sp. in domestic rabbits in Henan Province, Central China, and provide foundation for prevention and control of the disease caused by Blastocystis sp. in domestic rabbits. DNA was extracted from 286 fresh rabbit faecal samples collected from four areas of Henan Province, Central China. All DNA samples were screened using PCR and positive samples were sequenced to identify individual subtypes based on the small ribosomal subunit (SSU rRNA) gene. The overall infection rate of Blastocystis sp. in domestic rabbits in Henan Province was 15% (43/286). Three subtypes were identified, including ST1 (26/43, 60%), ST3 (5/43, 12%) and ST7 (12/43, 28%), all of which belonged to potentially zoonotic subtypes, ST1 was the dominant gene subtype. These results showed that infection with Blastocystis sp. was common in domestic rabbits in Henan Province, Central China, and was represented by zoonotic subtypes. Therefore, special attention should be paid to reduce the risk of transmission of Blastocystis sp. from domestic rabbits to humans.
The aim of this study was to assess the effects of radiofrequency electromagnetic field (RF EMF) on heart rate variability (HRV) in rabbits with intensity slightly exceeding the limits for occupations. Totally 21 New Zealand white rabbits divided into two groups were used in this double-blind study. The first group of animals without general anesthesia was subjected to HRV examination under exposure to a device generated RF EMF source (frequency 1788 MHz, intensity 160 V/m, lasting 150 min.). The second group (premedications + α chloralose mg/kg) underwent the same protocol under the exposure to the real RF EMF signal from the base stations of mobile providers (frequency range 1805 - 1870 MHz - corresponding to the downlink signal of Slovak mobile providers, 160 V/m, 150 min., respectively). Individual 5-min records were used to analyze the HRV parameters: heart rate and root Mean Square of the Successive Differences (rMSSD) for time domain analysis and spectral powers in the low (LF-VFS) and high frequency (HF-VFS) bands for frequency domain analysis. Our study revealed the increased in HRV parameters (HF-HRV, rMSSD) associated with lower heart rate indicating increased cardiac vagal control under the exposure to RF EMF in experimental methods., Jakub Misek, Marcel Veterník, Ingrid Tonhajzerova, Viera Jakusova, Ladislav Janousek, Jan Jakus., and Obsahuje bibliografii