ABSTRACT
The in vitro blood-brain barrier (BBB) model was established with bovine brain microvessel endothelial cells (BBMECs). The characteristics of BBMECs were identified by morphological and functional studies. BBMECs began to grow as spindle shaped cells and distinctly formed the monolayer of whirling appearance by 6 to 7 days after plating. Transendothelial electrical resistance (TEER) of the monolayer increased through 11 days and then started to decrease. The gamma-GTP activity (1791.5+/-397.8 nmol/min/mg of protein) and alkaline phosphatase activity (15.0+/-7.8 micromol/min/mg of protein) were high. BBMECs in culture were characterized by the binding of anti-vWF, anti-ZO-1, anti-vimentin, and anti-fibronectin antibodies. They failed to react with anti-GFAP, anti-GalC, and antineurofilament 160/200 kD antibodies, markers for astrocyte, oligodendrocyte, and neuron, respectively. Decreasing order of the permeability through the BBMEC monolayers of paracellular transport model drugs was mannitol, sucrose, and PEG-4000. The permeability of transcellular transport model drugs, progesterone and propranolol was much higher than that of paracellular transport model drugs. The BBMECs cultured on porous membrane have been qualified as an in vitro BBB model and also can be used for the BBB transport study in the drug development and for the BBB transport mechanism of drugs.
ABSTRACT
A splanchic artery occlusion for 90 min followed by reperfusion of the mesenteric circulation resulted in a severe form of circulatory shock characterized by endothelial dysfunction, severe hypotension, marked intestinal tissue injury, and a high mortality rate. The effect of rutin, a flavonoid having antiprostanoid, anti-inflammatory, antithrombotic, antioxidant effect, were investigated in a model of splanchnic artery occlusion (SAO) shock in urethane anesthetized rats. Occlusion of the superior mesenteric artery for 90 min produced a severe shock state resulted in a fatal outcome within 120 min of reperfusion in many rats. Rutin was given as a bolus (1.28 mg/kg) 10 min prior to reperfusion. Administration of rutin significantly improved mean arterial blood pressure in comparison to vehicle treated rats (p<0.05). Rutin treatment also resulted in a significant attenuation in the increase in plasma amino nitrogen concentration, intestinal myeloperoxidase activity, intestinal lipid peroxidation, infiltration of neutrophils in intestine and thrombin induced adherence of neutrophils to superior mesentric artery segments. These results suggest that rutin provides beneficial effects in part by preserving endothelial function and attenuating neutrophil accumulation in the ischemic reperfused splanchnic circulation.
Subject(s)
Animals , Rats , Antioxidants , Arterial Pressure , Arteries , Fatal Outcome , Hypotension , Intestines , Ischemia , Lipid Peroxidation , Mesenteric Artery, Superior , Mortality , Neutrophils , Nitrogen , Peroxidase , Plasma , Reperfusion , Rutin , Shock , Splanchnic Circulation , Thrombin , UrethaneABSTRACT
Under certain pathophysiological conditions, such as inflammation and ischemia, the concentration of H+ ion in the tissue surrounding neurons is changed. Variations in H+ concentration are known to alter the conduction and/of the gating properties of several types of ion channels. Several types of K+ channels are modulated by pH. In this study, the whole cell configuration of the patch clamp technique has been applied to the recording of the responses of change of external pH on the delayed rectifier K+ current of cultured DRG neurons of rat. Outward K+ currents were examined in DRG cells, and the Charybdotoxin and Mn2+ could eliminate Ca2+-dependent K+ currents from outward K+ currents. This outward K+ current was activated around -60 mV by step depolarizing pulses from holding potential -70 mV. Outward K+ currents were decreased by low external pH. Activation and steady-state inactivation curve were shifted to the right by acidification, while there was small change by alkalization. These results suggest that H+ could be alter the sensory modality by changing and modifying voltage-dependent K+ currents, which participated in repolarization.