摘要:

There are no reports on the autologous transplantation and patency of microvessels in living tissue. We autotransplanted microvessel fragments (Mvf) labeled with Dil-Ac-LDL into the peritoneum and then observed the peritoneum for 7 days postoperatively with a conventional fluorescence or laser scanning confocal microscope. We illustrated a neomicrovascular network of transplanted Mvf labeled with Dil-Ac-LDL in the peritoneum with both a fluorescence and a laser scanning confocal microscope. Furthermore, we demonstrated not only the existence of erythrocytes in the lumina of transplanted Dil-Ac-LDL-labeled Mvf, but also the presence of India ink perfused through the superior mesenteric artery in the lumina of the labeled Mvf. This evidence directly suggests that transplanted Mvf can survive and proliferate to connect adjacent microvascular branches of the superior mesenteric artery in the very early phase of wound healing. Moreover, these findings imply that implantation of Mvf in the microvascular ischemic circulatory tissue might accelerate angiogenesis to reconstitute a new microvascular network connecting to the nearby host microvascular system, which ultimately improves microcirculation.

ISSN:0167-6865    

DOI:10.1159/000179224

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Intravital microscopy of the hamster cheek pouch microvasculature was used for in vivo studies of the effects of diltiazem (calcium antagonist, group I), prazosin (α1-adrenergic receptor antagonist, group III), rauwolscine (α-adrenergic receptor antagonist, group V), phenylephrine (α-adrenergic receptor agonist, group VII) and isoproterenol (β-adrenergic receptor agonist, group IX) in a concentration range of 10-9-10-5M and their combination with 10-7M of buflomedil (groups II, IV, VI, VIII and X) on mean arteriolar internal diameter and spontaneous vasomotion. All drugs were applied topically. Vasomotor activity was studied in 270 arterioles (internal diameter range 20.0-75.0 µm) of 60 preparations. Diltiazem dose dependently increased the microvascular diameter and reduced and ultimately abolished the vasomotion frequency and amplitude. Addition of buflomedil did not significantly change the vasodilation evoked by diltiazem and potentiated its depressive effect on vasomotion frequency and amplitude. Prazosin dose-dependently increased the arteriolar diameter and reduced the vasomotion frequency and amplitude. Addition of buflomedil potentiated both the vasodilation elicited by prazosin and the reduction in vasomotion frequency and amplitude. Rauwolscine tended to elicit vasoconstriction at lower concentrations (10-9 and 10-8M) and vasodilation at higher concentrations (10-5M) and significantly reduced the vasomotion frequency and amplitude. Addition of buflomedil potentiated both the vasodilation and the reduction in vasomotion frequency, but tended to increase the vasomotion amplitude. Phenylephrine significantly decreased the mean arteriolar internal diameter, moderately decreased the vasomotion frequency and did not significantly change the vasomotion amplitude. Addition of buflomedil totally blocked the vasoconstriction elicited by phenylephrine, potentiated the reduction in vasomotion frequency and amplitude when combined with lower concentrations of phenylephrine (10-9–10-7M) and restored the vasomotion frequency and amplitude when combined with higher concentrations of phenylephrine (10-6 and 10-5M). Isoproterenol significantly increased the mean arteriolar diameter and reduced the vasomotion frequency and amplitude. Addition of buflomedil did not significantly change either the vasodilation or the reduction in vasomotion frequency and amplitude. The effects observed with buflomedil on the hamster cheek pouch microcirculation further support its properties as a competitive inhibitor of α-adrenergic receptors, not selective for either the α1- or α2-adrenergic receptor subtype, and as a weak calcium a

ISSN:0167-6865    

DOI:10.1159/000179225

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

The objective of this study was to determine the role of hypotension and hypoperfusion in the induction of regular slow-wave flowmotion (SWFM) in skeletal muscle in vivo. SWFM and microcirculatory muscle blood flow (MBF) were assessed by laser Doppler flowmetry in anesthetized rats exposed to: (1) graded hemorrhage (n = 15); (2) partial occlusion of the feeding artery (n = 6); (3) partial occlusion of the vein (n = 6), and (4) the vasodilator hydralazine (n = 10). Mean arterial pressure (MAP) was significantly reduced to 65 ± 2.1% after hemorrhage and hydralazine before (64 ± 2.4%) and after (42 ± 1.8%) additional blood loss, but remained unchanged after venous occlusion. The pressure of the feeding artery fell to 38 ± 1.2% after partial occlusion. MBF dropped significantly to 74 ± 4.2% after hemorrhage, 54 ± 5.6% after arterial and 53 ± 3.0% after venous occlusion. Hydralazine caused MBF to rise to 192 ± 21.8% before additional blood withdrawal and returned to normal values after it. SWFM was observed in all animals after hemorrhage and arterial occlusion, but in none after venous occlusion. In the hydralazine group, SWFM occurred only after blood loss. The hemoglobin concentration was reduced to 82 ± 2.1 % after hemorrhage. It remained normal after hydralazine administration, but decreased to 79 ± 1.2% after the subsequent blood withdrawal. We conclude that arterial hypotension, but not hypoperfusion, induces SWFM, and hyperperfusion prevents it. Our results support the hypothesis that SWFM is generated by a reduction of vascular wal

ISSN:0167-6865    

DOI:10.1159/000179226

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Although microvasculitis is one of the more common manifestations of systemic lupus erythematosus, there is no data on the hemodynamics of the skin microcirculation in such patients. The combination of dynamic capillaroscopy measuring capillary blood cell velocity (CBV) and laser Doppler fluxmetry (LDF) was used to simultaneously evaluate the nutritional and the total skin microcirculation in the fingers of 24 consecutive patients with SLE, using normal matched subjects as controls. The nutritional skin flow, as assessed by the CBV, was significantly impaired in patients, as compared with controls, both at rest (p = 0.001) and during postocclusive reactive hyperemia (p = 0.006). By contrast, no differences were observed in total skin microcirculation, as assessed by LDF (n.s.). There was no significant correlation between hemodynamic parameters and the presence of Raynaud’s phenomenon, morphological capillary changes or anticardiolipine antibodies. There was no correlation between the magnitude of the alteration of the capillary blood flow and capillary morphological abnormalities, suggesting that the microvascular damage might be caused by different pathophysiological mechanism

ISSN:0167-6865    

DOI:10.1159/000179227

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

A modified technique of vital capillary microscopy with intraarterial application of Na-fluorescein has been introduced in the study of nutritional skin microcirculation to assess skin microcirculation of different diabetic patients, comprising one group without neurocutaneous complications (group 2; n = 9), one suffering only from neuropathy (group 3; n = 9) and one with trophic skin lesions in the contralateral foot (group 4; n = 8), all without macroangiopathy, compared to healthy controls (group 1; n = 9). Femoroarterial injection of small boli (10 mg) of Na-fluorescein allowed repeated investigation of the dye appearance times (AT) and capillary-filling times of forefoot skin capillaries within small periods of time before, during and after reactive hyperemia. At rest, AT was significantly shorter in patients of group 4(16.8 ± 4.4 s; p < 0.05) compared with groups 1-3 (34.3 ± 12.8; 31.7 ± 11.7 and 35.9 ± 15.3 s). Fifteen seconds after the end of arterial occlusion, dye propagation to the skin was markedly accelerated in groups 1-3(19.8 ± 14.0; 14.4 ± 7.6 and 18.7 ± 10.6 s, respectively; p < 0.001), but prolonged in group 4 (18.4 ± 7.4 s). After 10 min, the values at rest were reestablished. No differences between the four groups were found concerning capillary density and morphology. It is concluded that the development of skin lesions in diabetic patients without significant macroangiopathy may be favored by hyperperfusion and impaired vasoregulation. Intraarterial dye injection presents a valuable tool to assess dynamic alterations of the microcirculation at the level of skin capi

ISSN:0167-6865    

DOI:10.1159/000179228

出版商:S. Karger AG    

年代:1997

数据来源: Karger

ISSN:0167-6865    

DOI:10.1159/000179229

出版商:S. Karger AG    

年代:1997

数据来源: Karger

ISSN:0167-6865    

DOI:10.1159/000179230

出版商:S. Karger AG    

年代:1997

数据来源: Karger