A new approach to the integrity of dual blood-brain barrier functions of global ischemic rats. Barrier and carrier functions.
نویسندگان
چکیده
BACKGROUND AND PURPOSE We studied the influence of reperfusion on carrier and barrier functions of the blood-brain barrier after transient global ischemia in rats. METHODS We used iodine-125-labeled 3-iodo-alpha-methyl-L-tyrosine and carbon-14-labeled sucrose as tracers for studying carrier and barrier functions of the blood-brain barrier, respectively. Brain uptakes of these two tracers were measured in Wistar rats subjected to either 15- or 30-minute four-vessel occlusion developed by Pulsinelli and Brierly before recirculation for 3, 6, 24, 48, and 72 hours. Tracer (5 microCi) was injected intravenously in each rat 30 minutes before killing the animal. RESULTS Following 15- or 30-minute ischemia, [14C]sucrose uptakes were significantly higher at 3 and 6 hours of reperfusion before recovery to control values after reperfusing for 24 to 48 hours in almost all brain regions. However, a rebound in radioligand uptake was significantly manifested in some sites at 72 hours after reperfusion (p < 0.05 to p < 0.01). Uptakes of 125I-3-iodo-alpha-methyl-L-tyrosine were brain site-dependent: significantly (p < 0.05) higher in cortex (3 and 48 hours after reperfusion) and thalamus (3, 6, and 48 hours after reperfusion) but significantly (p < 0.05 to p < 0.01) lower in striatum, cortex (72 hours after reperfusion), and midbrain (6, 24, and 72 hours after reperfusion). Because the [14C]sucrose uptake in brain was 10% lower than that of 125I-3-iodo-alpha-methyl-L-tyrosine, the change in absolute transport of the latter tracer was approximated to its brain uptake. CONCLUSIONS The carrier and barrier functions of the blood-brain barrier should be evaluated separately. The radioligand 125I-3-iodo-alpha-methyl-L-tyrosine may serve as a useful tool to evaluate the carrier function of the blood-brain barrier after transient cerebral ischemia in rats.
منابع مشابه
Candesartan Attenuates Ischemic Brain Edema and Protects the Blood–Brain Barrier Integrity from Ischemia/Reperfusion Injury in Rats
Background: Angiotensin II (Ang II) has an important role on cerebral microcirculation however, its direct roles in terms of ischemic brain edema need to be clarified. This study evaluated the role of central Ang II by using candesartan, as an AT1 receptor blocker, in the brain edema formation and blood-brain barrier (BBB) disruption caused by ischemia/reperfusion (I/R) injuries in rat. Methods...
متن کاملIntensification of brain injury and blood-brain barrier permeability by short-term hypertension in experimental model of brain ischemia/reperfusion
Introduction: Arterial hypertension is one of the causes of stroke, and as one of the vasculotoxic conditions intensifies ischemic stroke complications. The aim of the present study was to analyze the effects of short-term cerebral hypertension on ischemia/reperfusion injury and pathogenesis of ischemic stroke. Methods: The experiments were performed on three groups of rats (N=36) Sham, cont...
متن کاملDual Blood-Brain Barrier Functions of Global Ischemic Rats Barrier and Carrier Functions
Background and Purpose: We studied the influence of reperfusion on carrier and barrier functions of the blood-brain barrier after transient global ischemia in rats. Methods: We used iodine-125-labeled 3-iodo-a-methyl-L-tyrosine and carbon-14-labeled sucrose as tracers for studying carrier and barrier functions of the blood-brain barrier, respectively. Brain uptakes of these two tracers were mea...
متن کاملNeuroprotective Effects of Allicin on Neurological Scores, Blood Brain Barrier Permeability and Brain Edema Following Severe Traumatic Brain Injury in Male Rats: A Behavioral, Biochemical and Histological Study
Background and purpose: Allicin has a wide range of pharmacological functions, all of which can be demonstrated in anti-inflammatory, antioxidant, antifungal and anti-tumor activities. In this research, we investigated the neuroprotective role of allicin in the process of diffuse traumatic brain injury and its effect on interleukin levels and histological changes in rats. Materials and method...
متن کاملQuantitative evaluation of Blood Brain Barrier permeability in transient focal cerebral ischemia in the rat
Introduction: Development of brain edema following focal cerebral ischemia exacerbates primary ischemic injury. Blood brain barrier (BBB) opening is an important part of edema named as vasogenic brain edema. In this study, quantitative alterations of BBB permeability is experimentally evaluated using transient focal cerebral ischemia in the rat. Methods: Two groups of male rats (ischemic and sh...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Stroke
دوره 24 2 شماره
صفحات -
تاریخ انتشار 1993