RÉSUMÉ
Interstitial fluid (ISF) flow through vascular adventitia has been discovered recently. However, its kinetic pattern was unclear. We used histological and topographical identification to observe ISF flow along venous vessels in rabbits. By magnetic resonance imaging (MRI) in live subjects, the inherent pathways of ISF flow from the ankle dermis through the legs, abdomen, and thorax were enhanced by paramagnetic contrast. By fluorescence stereomicroscopy and layer-by-layer dissection after the rabbits were sacrificed, the perivascular and adventitial connective tissues (PACTs) along the saphenous veins and inferior vena cava were found to be stained by sodium fluorescein from the ankle dermis, which coincided with the findings by MRI. The direction of ISF transport in a venous PACT pathway was the same as that of venous blood flow. By confocal microscopy and histological analysis, the stained PACT pathways were verified to be the fibrous connective tissues, consisting of longitudinally assembled fibers. Real-time observations by fluorescence stereomicroscopy revealed at least two types of spaces for ISF flow: one along adventitial fibers and another one between the vascular adventitia and its covering fascia. Using nanoparticles and surfactants, a PACT pathway was found to be accessible by a nanoparticle of <100 nm and contained two parts: a transport channel and an absorptive part. The calculated velocity of continuous ISF flow along fibers of the PACT pathway was 3.6‒15.6 mm/s. These data revealed that a PACT pathway was a "slit-shaped" porous biomaterial, comprising a longitudinal transport channel and an absorptive part for imbibition. The use of surfactants suggested that interfacial tension might play an essential role in layers of continuous ISF flow along vascular vessels. A hypothetical "gel pump" is proposed based on interfacial tension and interactions to regulate ISF flow. These experimental findings may inspire future studies to explore the physiological and pathophysiological functions of vascular ISF or interfacial fluid flow among interstitial connective tissues throughout the body.
RÉSUMÉ
Objective To study the effect of tissue plasminogen activator (t-PA) on p57NTR ,inflammatory reaction ,immune regulation and oxidative stress and its effect on intimal hyperplasia .Methods The vascular injury treatment was performed in the diabetic rabbit model with carotid arterial adventitia stripping ,meanwhile t-PA controlled release microspheres were given ,the nerve distribution in the local blood vessels was observed by immunohistochemical staining .The change of nerve remodeling in the control group and treatment group was observed ,meanwhile the effect of giving t-PA controlled release microspheres on the release of ace-tylcholine and norepinephrine was detected .RT-PCR was used to detect local vascular tissue inflammation ,immune effects and oxi-dative stress .The sympathetic neurons and smooth muscle cell co-culture was adopted ,then giving glyoxal treatment as the athero-sclerosis cell model .With the t-PA treatment group as the intervention group ,the effect of t-PA on the number of cholinergic neu-ron ,and synaptic connections between the smooth muscle cells and acetylcholine secretion was observed .The change of t-PA-MMP-p75NTR and NF-kappa B signaling pathway were detected by RT-PCR .Results The vascular injury treatment was performed in the diabetic rabbit model with carotid arterial adventitia stripping ,meanwhile t-PA controlled release microspheres were given ,the nerve distribution in the local blood vessels was observed by immunohistochemical staining .The change of nerve remodeling in the control group and treatment group was observed ,meanwhile the effect of giving t-PA controlled release microspheres on the release of acetylcholine and norepinephrine was detected .RT-PCR was used to detect local vascular tissue inflammation ,immune effects and oxidative stress .The sympathetic neurons and smooth muscle cell co-culture was adopted ,then giving glyoxal treatment as the ath-erosclerosis cell model .With the t-PA treatment group as the intervention group ,the effect of t-PA on the number of cholinergic neuron ,and synaptic connections between the smooth muscle cells and acetylcholine secretion was observed .The change of t-PA-MMP-p75NTR and NF-kappa B signaling pathway were detected by RT-PCR .Conclusion t-PA activates MMPs and feedback in-hibits p75NTR-NF-kappa B signaling pathway to increase vascular adventitia autonomic nerve reconstruction and delay the occur-rence and development of atherosclerosis disease .