Biomedical subjects

H Ooboshi

Publications and source records attributed to H Ooboshi.

At least 37 records · Page 2Linked to original sources

PubMed1998

Protein kinase C modulates ischemia-induced amino acids release in the striatum of hypertensive rats.

The role of protein kinase C (PKC) in mediating the ischemia-induced release of amino acids in the striatum was studied using an in vivo brain dialysis technique in the striatum of spontaneously hypertensive rats (SHRs). Using HPLC combined with fluorescence detection methods, we investigated the concentrations of amino acids in the dialysates produced by 20 min of transient forebrain ischemia. We studied the effects of an inhibitor of PKC, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H7) and another isoquinoline analog (HA1004) with less inhibitory effect on the C kinase in ischemia-induced amino acids release. Bilateral carotid artery occlusion caused a marked reduction in the striatal blood flow by 91 +/- 6%. The extent of the cerebral blood flow (CBF) reduction were essentially the same among H7-, HA1004-, and the vehicle-treated groups. Forebrain ischemia produced a marked increase in glutamate (21-fold of the basal concentration), aspartate (19-fold) and taurine (16-fold). Pretreatment with H7 markedly attenuated the ischemia-in-duced release of these three amino acids to 3, 3 and 4-fold of the basal values, respectively. Increase of gamma-aminobutyric acid (GABA) was also attenuated by H7 (vehicle; 2.46 +/- 1.26 microM, H7; 0.62 +/- 0.75 mM). HA1004 did not affect the release of glutamate, aspartate or GABA during ischemia. The ischemia-induced release of taurine was significantly inhibited by HA1004 but the effect was much smaller than that of H7. These results thus indicate that PKC plays a major role in the ischemia-induced release of amino acids in the striatum of SHR.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed1998

Improvement of relaxation in an atherosclerotic artery by gene transfer of endothelial nitric oxide synthase.

Gene transfer with replication-deficient adenovirus is a useful tool to study vascular biology. We have reported that overexpression of endothelial nitric oxide (NO) in carotid arteries from normal rabbits augments vasorelaxation mediated by NO. In this study, we tested the hypothesis that adenovirus-mediated gene transfer of endothelial nitric oxide synthase (eNOS) improves impaired relaxation of atherosclerotic vessels. We used 2 replication-deficient adenoviruses: AdeNOS, which carries cDNA for eNOS, and Adbetagal, which expresses beta-galactosidase. Common carotid arteries from 10 New Zealand White (NZW; plasma cholesterol, 79+/-13 mg/dL) and 10 Watanabe heritable hyperlipidemic (WHHL; plasma cholesterol, 452+/-39 mg/dL) rabbits were incubated in organ culture with AdeNOS, Adbetagal, or vehicle alone. Carotid arteries from WHHL rabbits had mild to moderate atherosclerotic lesions. Histochemical staining for beta-galactosidase and immunohistochemistry for eNOS indicated transgene expression in the endothelium and adventitia in both NZW and WHHL rabbits. Expression of eNOS determined with Western blot analysis after incubation with AdeNOS tended to be higher in vessels from WHHL rabbits than NZW rabbits. Effects of transgene expression on vascular function were examined by recording isometric tension 1 day after transduction. After precontraction with phenylephrine, acetylcholine produced significantly less relaxation in vessels from WHHL rabbits than in vessels from NZW rabbits. Relaxation in response to acetylcholine was greater in carotid arteries from both NZW and WHHL rabbits that were transfected with AdeNOS than in vessels treated with vehicle or Adbetagal. Vasorelaxation in response to acetylcholine was inhibited by Nomega-nitro-L-arginine. Responses to sodium nitroprusside were similar after treatment with vehicle alone, Adbetagal, or AdeNOS in both groups of rabbits. Thus, overexpression of eNOS with an adenoviral vector improves impaired NO-mediated relaxation in atherosclerotic arteries.

Adenoviridae↗

PubMed1998

Cationic polymer and lipids enhance adenovirus-mediated gene transfer to rabbit carotid artery.

BACKGROUND AND PURPOSE: Improvement of efficiency of gene transfer to endothelium could be useful for several applications. We tested the hypothesis that cationic nonviral molecules augment adenovirus-mediated gene transfer to blood vessels, perhaps by alteration of the surface charge of adenovirus and facilitation of binding to endothelium. METHODS: Carotid arteries from rabbits were incubated in vitro for 0.5 to 2 hours with an adenoviral vector alone or noncovalent complexes of adenovirus with poly-L-lysine (a cationic polymer) or lipofectin (a cationic lipid). Binding of adenovirus to the vessels was evaluated immediately after incubation with virus, and assay of transgene (ss-galactosidase) activity and histochemistry were performed 24 hours after gene transfer. To determine whether cationic molecules can be used to augment alteration of vascular function by adenovirus-mediated gene transfer, we also examined effects on gene transfer of endothelial nitric oxide synthase. RESULTS: Assay of ss-galactosidase activity indicated that both cationic molecules increased transgene expression in vessels by approximately 5- to 6-fold. In contrast, when endothelium was removed from the vessels after gene transfer, poly-L-lysine and lipofectin did not significantly increase transgene activity. Histochemistry for ss-galactosidase also suggested that the adenovirus-cationic molecule complexes augmented transgene expression mainly in the endothelium. In addition, we found that complexing adenovirus with cationic molecules increased binding of adenovirus to the vessels. After gene transfer with recombinant adenovirus containing endothelial nitric oxide synthase, calcium ionophore (A23187) produced greater relaxation of vessels treated with adenovirus complexed with poly-L-lysine or lipofectin than those treated with adenovirus alone. CONCLUSIONS: Cationic molecules improve the efficiency of adenovirus-mediated gene transfer to blood vessels.

Adenoviridae↗

PubMed1998

Adenovirus-mediated gene transfer in vivo to cerebral blood vessels and perivascular tissue in mice.

BACKGROUND AND PURPOSE: Gene transfer to cerebral blood vessels has been accomplished in rats and dogs by injection of replication-deficient adenovirus into cerebrospinal fluid. In this study we examined transgene expression after injection of adenovirus into the cerebrospinal fluid of mice. Responses were observed in ICR mice and C57BL/6 mice, which are outbred and inbred strains, respectively. METHODS: We injected replication-deficient recombinant adenovirus expressing nuclear targeted beta-galactosidase, driven by either the Rous sarcoma virus promoter (AdRSV-betaGal) or the cytomegalovirus promoter (AdCMV-betaGal), into the cisterna magna of anesthetized ICR and C57BL/6 strains of mice. The brains were examined from 1 to 21 days after injection by chemiluminescent enzyme activity assay or histochemical staining. RESULTS: After injection of AdRSV-betaGal, expression of beta-galactosidase in ICR mice peaked on day 7 and returned to basal by day 14. Expression of beta-galactosidase in C57BL/6 mice was maximal on days 7 to 14 and was minimal by day 21 after injection of AdRSV-betaGal. After injection of AdCMV-betaGal in C57BL/6 mice, peak expression of transgene occurred on day 1 and was greatly diminished by day 3. Transgene expression was observed primarily on the ventral surface of the brain, with preferential expression in leptomeninges and adventitia along the major cerebral arteries of that region. CONCLUSIONS: Injection of recombinant adenovirus in the cisterna magna resulted in transgene expression in leptomeninges and perivascular tissue of cerebral blood vessels in two strains of mice. The CMV promoter elicited rapid but short-lived expression of the transgene, while the RSV promoter elicited slower, more sustained transgene expression. Expression of AdRSV transgene was prolonged in C57BL/6 mice compared with ICR mice. This approach for gene transfer may be useful to study cerebral vascular biology in genetically altered strains of mice.

Adenoviridae↗

PubMed1997

Age-related changes in the DNA and RNA content of the brain in spontaneously hypertensive rats.

To elucidate the effects of aging accompanied with hypertension on brain nucleic acid, we measured both the DNA and RNA contents of six specific brain regions in adult (5-6 months old) and aged (18-22 months old) female spontaneously hypertensive rats (SHRs). Although no statistical difference was observed in the RNA content, the DNA content did tend to increase in the hippocampal CA1 of aged SHR (4.24 +/- 0.55 ng/microgram protein, mean +/- SD, n = 6) in comparison to that of adult SHR (3.21 +/- 0.71 ng/microgram protein, n = 4). Hence, aged SHRs showed a significant decrease in the RNA to DNA ratio in the CA1 subfield of the hippocampus (3.79 +/- 0.61) compared to adult SHR (5.27 +/- 0.81). On the other hand, no other regions, except for the dorsolateral region of the striatum, showed any difference in the RNA/DNA ratio between aged and adult SHR. We therefore conclude that subtle changes in the nucleic acid occur in vulnerable regions of the brain in aged SHRs.

Aging↗

PubMed1997

Intrapericardial administration of adenovirus for gene transfer.

Gene transfer to the heart has been accomplished with intravascular administration of adenoviral vectors into the pericardial sac, by increasing the duration of exposure to the adenovirus, would result in gene expression in the pericardium and perhaps myocardium and therefore might provide an alternative method to intravascular administration for gene transfer. We injected a replication-deficient adenovirus (average 1 x 10(12) particles/ml in 3% sucrose; 1 x 10(10) plaque forming units/ml containing cDNA encoding a nuclear-targeted bacterial beta-galactosidase into the pericardial sac of dogs. Samples of the pericardium and heart were examined for enzymatic activity of beta-galactosidase and after histochemical staining with 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside. One day after injection of the adenovirus (1-3 ml), beta-galactosidase activity was highest in the parietal pericardium and left atrial tissue and lower in the right and left ventricles. Histochemical expression of the transgene was predominantly in the visceral pericardium of atria and ventricles and occasionally in the epicardial myocytes, arterioles, and venules. Pretreatment with doxycycline (5 mg) before adenovirus administration increased transgene activity in left ventricles. Thus adenovirus injected into the pericardial sac provides an effective method for gene transfer to the visceral and parietal pericardium over atria and ventricles.

Adenoviridae↗

PubMed1997

Altered vascular function after adenovirus-mediated overexpression of endothelial nitric oxide synthase.

Gene transfer with replication-deficient adenovirus is a potentially useful tool to study vascular biology. We have constructed a replication-deficient adenovirus (AdRSVeNOS) that carries cDNA for endothelial nitric oxide synthase (eNOS). Transfection of COS-1 cells with AdRSVeNOS increased nitric oxide synthase activity (measured as production of L-citrulline from L-arginine) that was calcium dependent and inhibited by N omega-nitro-L-arginine methyl ester. To investigate effects of overexpression of eNOS on vascular function, we incubated common carotid arteries from rabbits in organ culture with AdRSVeNOS or AdRSV beta gal encoding beta-galactosidase. Transgene expression and responses to vasoactive agents were examined 1 day after transduction. Histochemical staining of beta-galactosidase and immunohistochemistry for eNOS indicated transgene expression in endothelium and adventitial cells. After precontraction with phenylephrine, vessels treated with AdRSVeNOS demonstrated greater relaxation to acetylcholine than vessels treated with vehicle or AdRSV beta gal. Relaxation to calcium ionophore A-23187 was much greater in vessels treated with AdRSVeNOS than in vessels treated with vehicle or AdRSV beta gal. Augmented relaxation in response to A-23187 was also observed after denudation of endothelium in vessels treated with AdRSVeNOS and was inhibited by N omega-nitro-L-arginine. Thus vasorelaxation in response to stimuli that release nitric oxide is augmented after adenovirus-mediated overexpression of eNOS. Transgene expression in adventitial cells appears to be sufficient to alter vasomotor function.

Adenoviruses, Human↗

PubMed1997

Augmented adenovirus-mediated gene transfer to atherosclerotic vessels.

Vascular endothelium is an important target for gene transfer in atherosclerosis. In this study, we examined gene transfer to normal and atherosclerotic blood vessels from two species, using an organ culture method. Using normal aorta, we determined optimal dose, duration of exposure to adenovirus, and duration of incubation of vessels in tissue culture. Aortas from normal and atherosclerotic monkeys were cut into rings and incubated for 2 hours with a recombinant adenovirus, carrying the reporter gene for beta-galactosidase driven by a cytomegalovirus (CMV) promoter. After 20 hours of incubation, transgene expression was assessed with a morphometric method after histochemical staining and a chemiluminescent assay of enzyme activity. Expression of beta-galactosidase after histochemical staining, expressed as percentage of total cells, was similar in adventitial cells of normal monkeys (21 +/- 4%, mean +/- SE%) and atherosclerotic monkeys (25 +/- 12%). Transgene expression in endothelium was higher in atherosclerotic than in normal vessel (53 +/- 3% versus 27 +/- 7%, P < .05). Chemiluminescent assay indicated greater beta-galactosidase activity (2.5 +/- 0.6 mU/mg of protein) in the intima and media of atherosclerotic than normal vessels (0.6 +/- 0.2 mU/mg of protein, P < .05). Aortas from normal (n = 6) and atherosclerotic (n = 5) rabbits also were examined. Transgene expression (after histochemical staining) in endothelium was much greater in atherosclerotic than normal rabbits (39 +/- 3% versus 9 +/- 2%, P < .05) and expression in adventitial cells was similar (normal 23 +/- 2%, atherosclerotic 24 +/- 4%). Chemiluminescent assay indicated greater beta-galactosidase activity (1.2 +/- 0.4 mU/mg of protein) in the intima and media of atherosclerotic than normal vessels (0.2 +/- 0.1 mU/mg protein, P < .05). These findings suggest that an adenoviral vector with a CMV promoter provides similar transgene expression in adventitia of both normal and atherosclerotic vessels. Gene transfer to the endothelium was much more effective in atherosclerotic than in normal vessels. Thus it may be possible to achieve greater transgene expression in atherosclerotic than in normal arteries.

Adenoviridae↗

PubMed1997

Gene transfer to cerebral blood vessels after subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Vasospasm remains a major cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage. One step toward gene therapy to prevent spasm of cerebral vessels is to determine whether subarachnoid blood prevents transgene expression. METHODS: Vasospasm was induced in mongrel dogs using the double-hemorrhage intracranial-injection model. Diameter of the basilar artery was assessed by angiography, and profound vasospasm (> 50% decrease in diameter) was demonstrated at 4 and 7 days. Recombinant adenovirus expressing nuclear-targeted beta-galactosidase (reporter gene) under the control of the cytomegalovirus promoter was injected into the cisterna magna at the same time as (n = 9) or 2 days after (n = 4) injection of blood for induction of vasospasm. Brains were removed and examined histochemically for expression of nuclear beta-galactosidase. RESULTS: At 2 to 7 days, beta-galactosidase was expressed in leptomeninges over the brain stem, cortex, cerebral arteries, in small vessels in the cerebrum and brain stem, and in the ependymal lining of the ventricles. Transgene expression was observed in adventitia of blood vessels but not in vascular muscle or endothelium. Transgene expression was observed after simultaneous injection of virus and blood or when virus was injected 2 days after blood. CONCLUSIONS: The findings indicate that intracisternal injection of recombinant adenovirus can be used for gene transfer to cerebral blood vessels and overlying meninges, even in the presence of cisternal blood. We speculate that transfer of genes using recombinant viral vectors that encode for enzymes with vasodilator function to cerebral blood vessels and perivascular tissues may be useful for prevention or treatment of cerebral vasospasm after subarachnoid hemorrhage.

Animals↗

PubMed1997

Increase in TUNEL positive cells in aorta from diabetic rats.

TUNEL staining, which allows detection of fragmented DNA in situ, is commonly used as an indication of apoptosis. Recent studies suggest that apoptosis is increased in several pathophysiological conditions. In this study we examined the hypothesis that chronic diabetes is associated with an increase in TUNEL staining of the aorta. Diabetic rats were studied 4-5 months after injection of streptozotocin (50 mg/kg). Aorta of diabetic and control rats were examined for TUNEL staining, morphology by electron microscopy, and DNA contamination in RNA preparation by polymerase chain reaction (PCR). TUNEL staining of aortic sections showed a 6 fold increase of positive cells in the media of diabetic aorta (22 +/- 6%) (mean +/- SE) compared with aorta from age-matched controls (3.6 +/- 0.9%, p < 0.05). Electron microscopy demonstrated typical apoptotic cells and bodies in the media of aorta from diabetic but not control rats. DNA contamination was found in RNA prepared from diabetic aorta, which was detected using PCR, which is consistent with increased DNA fragmentation. Increased TUNEL staining was not observed in rats with hyperglycemia 3 days after injection of streptozotocin. In conclusion, severe chronic diabetes is associated with an increase in TUNEL staining, and perhaps apoptosis, in the aorta. We speculate that increased apoptosis may compensate for increased proliferative activity in diabetic blood vessels.

Animals↗

PubMed1997

Novel methods for adenovirus-mediated gene transfer to blood vessels in vivo.

Adenovirus-mediated gene transfer is a promising method for studies of vascular biology and potentially for gene therapy. Intravascular approaches for gene transfer to blood vessels in vivo generally require interruption of blood flow and have several limitations. We have used two alternative approaches for gene transfer to blood vessels in vivo using perivascular application of vectors. First, replication-deficient adenovirus expressing nuclear-targeted bacterial beta-galactosidase was injected into cerebrospinal fluid via the cisterna magna of rats. Leptomeningeal cells over the major arteries were efficiently transfected, and adventitial cells of large vessels and smooth muscle cells of small vessels were occasionally stained. When viral suspension was injected with the rat in a lateral position, the reporter gene was expressed extensively on the ipsilateral surface of the brain. Thus, adenovirus injected into cerebrospinal fluid provides gene transfer in vivo to cerebral blood vessels and, with greater efficiency, to perivascular tissue. Furthermore, positioning of the head may 'target' specific regions of the brain. Second, vascular gene delivery was accomplished by perivascular injection of virus in peripheral vessels. Injection of the adenoviral vector within the periarterial sheath of monkeys resulted in gene transfer to the vessel wall that was substantial in magnitude although limited to cells in the adventitia. Approximately 20% of adventitial cells expressed the transgene, with no gene transfer to cells in the intima or media. These approaches may provide alternative approaches for gene transfer to blood vessels, and may be useful for studies of vascular biology and perhaps vascular gene therapy.

Adenoviridae↗

PubMed1996

Vascular expression of inducible nitric oxide synthase is associated with activation of Ca(++)-dependent K+ channels.

We tested the hypothesis that expression of inducible nitric oxide synthase (NO-synthase) in response to endotoxin (lipopolysaccharide) produces activation of potassium channels. Contraction of the rat thoracic aorta in response to phenylephrine was measured in vitro after treatment in vivo for 15 hr with vehicle (control) or lipopolysaccharide (10 mg/kg i.p.). Impaired contraction in response to phenylephrine was used as an index of inducible NO-synthase expression, and activation of potassium channels was examined with specific inhibitors. Contraction in response to 10(-5) M phenylephrine (expressed as a percentage of contraction in response to 85 mM KCI) was markedly impaired in lipopolysaccharide-treated rats, compared with control (15 +/- 5% vs. 131 +/- 10%, P < .05, mean +/- S.E.). Expression of inducible NO-synthase mRNA in the vessel wall in lipopolysaccharide-treated rats was confirmed using reverse transcription-polymerase chain reaction. Contraction of the aorta in lipopolysaccharide-treated rats was restored to normal by 0.3 mM aminoguanidine (an inhibitor of inducible NO-synthase). Contraction of the aorta in response to phenylephrine, which was inhibited by lipopolysaccharide, was not affected by glibenclamide (an inhibitor of ATP-sensitive potassium channels) but was increased 2-fold (P < .05) by iberiotoxin (50 nM), an inhibitor of Ca(+2)-dependent potassium channels. Relaxation of the aorta in response to sodium nitroprusside, an exogenous donor of nitric oxide, and 8-bromo-cyclic GMP was also inhibited by iberiotoxin. These findings suggest that nitric oxide produced by vascular expression of inducible NO-synthase activates calcium-dependent potassium channels and that this mechanism may contribute to impaired vasoconstrictor responses during sepsis.

Animals↗

PubMed1995

Isradipine, a calcium channel blocker, attenuates the ischemia-induced release of dopamine but not glutamate in rats.

This study was designed to investigate the role of the L-type voltage sensitive calcium channel blocker, isradipine, in the ischemia-induced release of neurotransmitters. Male spontaneously hypertensive rats were subjected to cerebral ischemia for 60 min by bilateral carotid artery occlusion, and recirculated for 120 min. Isradipine (0.25 mg/kg n = 6) or vehicle (n = 6) was administered subcutaneously at 20 min before ischemia. In the striatum, cerebral blood flow was determined by the hydrogen clearance method and concentrations of extracellular dopamine and glutamate were measured by in vivo brain dialysis technique. Extracellular dopamine in the vehicle-treated group increased by 180-fold from the basal level, and glutamate by 24-fold during cerebral ischemia. Isradipine significantly attenuated the ischemic release of dopamine to 33-34% (P < 0.05) of the vehicle group, while it did not affect glutamate release. It is suggested that the release mechanism of dopamine and glutamate during cerebral ischemia may be different, especially in the dependence on the L-type calcium channels.

Animals↗

PubMed1995

Ischemia-induced release of amino acids in the hippocampus of aged hypertensive rats.

We have recently demonstrated the age-related vulnerability of hippocampal neurons to 20-min forebrain ischemia in spontaneously hypertensive rats (SHR). In the present study, we investigated the effect of aging on the release of amino acids in the hippocampus during transient cerebral ischemia for 20 min. Concentrations of extracellular amino acids and cerebral blood flow in the CA1 subfield were examined by an in vivo brain dialysis technique and a hydrogen clearance method, respectively, in adult (5-7 month) and aged (19-23 month) female SHR. During cerebral ischemia by bilateral carotid artery occlusion, cerebral blood flow to the hippocampus decreased to 20% of the resting values in both groups. After recirculation, both groups showed delayed hypoperfusion which was more prominent in the aged SHR. In the adult rats, concentrations of both aspartate and glutamate increased to approximately 8-fold of the resting values during ischemia. The elevation of these excitatory amino acids in the adult SHR was not significantly different from that in the aged rats. In contrast, the concentration of taurine increased 26-fold in the adult SHR but only 16-fold in the aged rats. Changes in other amino acids were not different between the two groups. These results indicate that an imbalance of excitatory and inhibitory amino acids, e.g., smaller release of taurine, during ischemia may, at least in part, contribute to the age-related vulnerability of hippocampal neurons to transient cerebral ischemia in SHR.

Aging↗

PubMed1995

Adenovirus-mediated gene transfer to normal and atherosclerotic arteries. A novel approach.

Previous studies of gene transfer to blood vessels in vivo have relied on intraluminal, catheter-based methods for delivery of adenoviral and other vectors. In this study, topical application of a replication-deficient adenoviral vector was used as an alternative method of gene transfer to the vessel wall. We administered recombinant adenovirus (1.0 x 1.5 x 10(10) pfu/mL) containing the nuclear targeted bacterial beta-galactosidase gene topically to arteries in normal and atherosclerotic cynomolgus monkeys. Topical administration was achieved by injection of adenoviral suspension within the periarterial sheath. Segments of femoral and carotid arteries were examined histochemically after staining with 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside 1 day after treatment with the adenovirus. After topical administration of virus, beta-galactosidase activity was observed in approximately 20% of cells in the adventitia in both normal and atherosclerotic arteries. There was no detectable beta-galactosidase activity in cells of the intima or media. Thus, topical application provides an alternative method for gene transfer to blood vessels in vivo. This approach, which does not require interruption of blood flow and does not disrupt the endothelium, may be useful for studies of vascular biology and perhaps gene therapy in both normal and atherosclerotic vessels.

Adenoviridae↗

PubMed1995

Adenovirus-mediated gene transfer in vivo to cerebral blood vessels and perivascular tissue.

Gene transfer to blood vessels in vivo generally requires interruption of blood flow. Thus, gene transduction to cerebral blood vessels in vivo has not yet been achieved. In this study, we injected replication-deficient adenovirus into cerebrospinal fluid in an attempt to transduce genes to cerebral blood vessels. Recombinant adenovirus (1 x 10(9) infectious units) expressing nuclear-targeted bacterial beta-galactosidase driven by the cytomegalovirus promoter was injected into the cisterna magna of Sprague-Dawley rats. The brains were examined histochemically after staining with 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside 1 to 7 days after injection of adenovirus. Leptomeningeal cells overlying the major arteries were efficiently transduced, and adventitial cells of large vessels and smooth muscle cells of small vessels were occasionally stained. beta-Galactosidase was expressed on days 1 and 3 after injection but was undetectable by day 7. Expression of the gene was 'targeted' by altering the position of the head. When viral suspension was injected while the rat was in a nose-down position, the reporter gene was expressed extensively on the ventral surface of the brain, especially along the circle of Willis. When the position was changed to the nose-up or lateral position, the inferior or lateral region of the brain was stained primarily. Administration of the virus into the lateral ventricle provided extensive expression in ependymal cells and leptomeninges with some transduction to cerebral blood vessels. Thus, adenovirus injected into cerebrospinal fluid provides gene transfer in vivo to cerebral blood vessels and, with greater efficiency, to perivascular tissue. Furthermore, cisternal delivery may target specific brain regions by positioning of the head.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoviridae↗

PubMed1994

Cerebral hemodynamics in hypertensive patients compared with normotensive volunteers. A transcranial Doppler study.

BACKGROUND AND PURPOSE: The present study was designed to examine cerebral hemodynamics in early and chronic stages of hypertension using transcranial Doppler sonography. METHODS: Our study population consisted of 16 chronic hypertensive patients with chronic and small deep brain infarction, 10 young early-stage hypertensive subjects, and 16 young normotensive healthy volunteers. Using three-dimensional mapping techniques, we identified the M1 portion of the middle cerebral arteries and measured mean blood flow velocity, and we calculated the Gosling pulsatility index (PI), Fourier PI of the first harmonic (Fourier PI1), and cerebrovascular resistance. RESULTS: Mean blood flow velocity in the young hypertensive group was statistically higher (71.7 +/- 11.7 cm/s [mean +/- SD]) than among chronic hypertensive subjects (56.9 +/- 21.4 cm/s, P < .01) and normotensive subjects (63.2 +/- 11.8 cm/s, P < .05). Gosling PI presented a mirror image of mean blood flow velocity in both hypertensive and normotensive subjects. Chronic hypertensive subjects showed significantly higher Fourier PI1 (0.32 +/- 0.05) and cerebrovascular resistance (2.08 +/- 0.82 mm Hg/cm per second) than normotensive subjects (0.25 +/- 0.03 and 1.31 +/- 0.23 mm Hg/cm per second [P < .005], respectively) or early-stage hypertensive subjects (0.25 +/- 0.04 and 1.44 +/- 0.26 mm Hg/cm per second [P < .02], respectively). CONCLUSIONS: Early-stage hypertensive subjects demonstrated higher velocity, normal Fourier PI1, and near normal vascular resistance, whereas chronic hypertensive subjects showed near normal velocity, higher Fourier PI, and greater vascular resistance. Results may indicate different degrees of cerebral arteriopathy and arteriolopathy between early and late stages of hypertension.

Adult↗

PubMed1993

Isradipine attenuates the ischemia-induced release of dopamine in the striatum of the rat.

We examined the effect of isradipine, a blocker of L-type voltage-sensitive Ca2+ channels (VSCCs), on the ischemia-induced release of dopamine in the rat striatum. Perfusion of 200 micrograms/ml isradipine in the striatum did not alter extracellular dopamine concentrations monitored by microdialysis. However, a marked increase (145-fold) in dopamine level during forebrain ischemia, developed by bilateral carotid artery occlusion, was attenuated significantly by 37% by isradipine whereas the intensity of ischemia, monitored by striatal blood flow, was unchanged. These results suggest that isradipine attenuates the ischemia-induced release of dopamine via blockade of L-type VSCCs on dopaminergic neurons.

3,4-Dihydroxyphenylacetic Acid↗