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<p><b>AIM</b>To investigate the effects of human urotensin II (hUII) on in vivo pia mater microcirculation in rats.</p><p><b>METHODS</b>Adult SD rats were randomly assigned to the following groups: control, sodium chloride injection (NS), UII(10(-6) mol/L), noradrenaline (NA, 10(-6) mol/L), and UII (10(-6) mol/L) + NA (10(-6) mol/L) groups. For recording of microcirculation images in pia mater, skull windows were performed and mounted on the stage of an intravital microscope equipped with a TV camera. Video images of microcirculation were stored by a video cassette recorder. Temporal changes in internal diameter and microcirculatory velocity of microvessels were measured by computer using the Image Pro software. The blood flow in cerebral tissues were measured with PIMII laser Doppler perfusion Imager (Lisca, Sweden).</p><p><b>RESULTS</b>The internal diameters of arterioles and venules in control group were (35.4 +/- 3.6) microm and (40.6 +/- 8.5) microm, respectively. In UII group, the arterioles and venules contracted immediately after treated with UII and up to the peak at 1 min, the internal diameters of arterioles and venules were (25.6 +/- 3.4) microm and (23.4 +/- 3.3) microm, respectively (P < 0.05). Both microcirculatory velocity in arterioles and venules had no significant changes in UII group (P > 0.05). The blood flow in meninges increased 1 min after treated with UII and up to high peak at 5 min (3.5 +/- 0.4 perfusion unit vs. control 2.3 +/- 0.6, P < 0.05).</p><p><b>CONCLUSION</b>hUII can contract microvessels in pia mater of rats and increase microcirculatory blood perfusion to cerebral tissue involved.</p>
Assuntos
Animais , Humanos , Masculino , Ratos , Circulação Cerebrovascular , Microcirculação , Ratos Sprague-Dawley , Urotensinas , FarmacologiaRESUMO
AIM：Damaging of Endothelial cells and adhesion of leukocytes and platelets were studied in rat mesentery microvessels after ischemia-reperfusion.METHODS：The model was made by losing blood and reperfusion from carotid artery in rat. Changes in mesentery microvessels were observed by high magnify microscope.RESULTS:Leukocyte and platelet adhesions were found in venules and co-capillaries 1-3 hours after ischemia-reperfusion. Endothelial cells were edema and vascular walls were thickening. Vacuoles formed in intracytoplasm of some vascular endothelium and some bigger endothelial vacuoles prominenced toward the luminal surface. Vacuoles had the shape of circle and the diameter was 10-30 μm. More vacuoles were found in arterioles, even there were several vacuoles in a arteriole. The biggest vacuole almost occupied 2/3 of vascular lumen.CONCLUSION：Edema and vacuole formation in vascular endothelium showed endothelial cells were damaged seriously after ischemia-reperfusion.
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AIM:To study whether ischemic preconditioning(IPC) has a protective effect against ischemia/reperfusion(I/R) injury in brain, and the possible relationship between IPC and the regulating function of microcirculation. METHODS: The I/R models were established both in I/R and IPC groups of Sprague-Dawley rats. Additional procedure was performed of short term cerebral ischemic preconditioning in IPC group 24 hours before I/R. Skull windows were performed through which microcirculation features were measured before ischemia, during ischemia, and reperfusion. Finally, brains were cut into slices and stained with red tetrazoline(TTC). RESULTS: Most TTC stained brains in I/R group presented irregular palely red areas which were few in IPC group. Compared with I/R group, IPC group presented relatively increase in accumulated length of capillaries, mean cerebral microcirculatory perfusion, and microcirculatory velocity in ischemic and reperfusion phase. There was no-reflow phenomenon in I/R group in reperfusion phase, which was substituted by the course of increasing reperfusion in IPC group. CONCLUSIONS:IPC could relieve the reduction of tissue perfusion during ischemia and the no-reflow phenomenon during reperfusion by improving the regulating function of microcirculation, which relatively promote the opening of capillaries and accelerating of microvascular flow, therefore protect brain from I/R injury.
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AIM: To investigate the effects of human urotensin Ⅱ (hUII) on in vivo mesenteric microcirculation in rats. METHODS: For recording of microcirculation images in the mesentery, the intestinal loop was mounted on the stage of an intravital microscope equipped with a TV camera. Video images of microcirculation were stored by a video cassette recorder. Temporal changes in internal diameter and microcirculatory velocity of microvesseles were measured by computer using the ImagePro software. The blood flow in intestinal wall was measured with PIMII laser Doppler perfusion Imager (Lisca Sweden). RESULTS: The internal diameters of arterioles and venules in control group were (21.4?2.3) ?m and (38.1?3.6) ?m,respectively. In UII group, the arterioles and venules contracted immediately after treated with UII and up to the peak at 1 min [(14.1?1.4) ?m and (22.2?5.2) ?m vs control,P0.05). The blood flow in intestinal wall increased 1 min after treated with UII and up to high peak at 5 min(6.4?1.1 perfusion unit vs control 4.2?0.9,P
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The changes of morphology, ATP and malonaldehyde (MDA) contents, xanthine oxidase (XO) activity as well as the glutathione peroxidase (GSH-px) activity of rabbit aortic endothelial cells under hyperoxia (100% O_2) for 0-72 hours were studied. We found that cellular morphological changes including swelling, shape variation after hyperoxia were time-dependent; after a temporarily increasing (24hr)(P
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In 1963, we treated 6 cases of acute radiation sickness (200-8,000 rad) resulted from an accidental uneven 60Co ?-ray irradiation; two of them died of intestinal type within two weeks. Four cases survived and one of them recovered from septicemic shock. Loss of hair, systemic infection, high fever and bleeding occurred in 5 patients. The essential therapeutic measures were strict isolation, preventive treatment with antiinfection drugs, fresh blood transfusion and sometimes infusion of blood formed elements. Among the survivals 2 received homologous bone marrow transplantation.The general conditions of 4 patients followed up for a period of 18 years are apparently good with transparent lens, normal thyroid function and immunological reactions, except one who had low serum IgG level. Three of them showed subnormal adrenocortical activity and impairment of sex gland function. A girl patient (400 rad) gave birth to 2 children one of which has retarded intellectual development. Serial EEG changes occurred only in those received high cranial doses. In all the cases persistence of chromosome aberration in peripheral lymphocytes was observed. With high doses (above 10,000 rad) remote regional effects led to amputation of one leg in one patient and pathological fracture of the femur in another.