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RA301/Tra2beta, a sequence-specific RNA-binding protein, was first cloned as a stress molecule in re-oxygenated astrocytes. In human vascular tissues, we have found enhanced RA301/Tra2beta expression in coronary artery with intimal thickening, and atherosclerotic aorta. Balloon injury to the rat carotid artery induced RA301/Tra2beta transcripts followed by expression of the antigen, which was detected in medial and neointimal vascular smooth muscle cells (VSMCs). In cultured VSMCs, hypoxia/re-oxygenation caused induction of RA301/Tra2beta and was accompanied by cell proliferation, both of which were blocked by the addition of either diphenyl iodonium, a NADPH oxidase inhibitor, PD98059, a mitogen-activated protein kinase kinase inhibitor, or antisense oligonucleotide for RA301/Tra2beta. Consistent with a link between RA301/Tra2beta and cell proliferation, platelet-derived growth factor also induced expression of RA301/Tra2beta in cultured VSMCS: These data suggest a possible role for RA301/Tra2beta in the regulation of VSMC proliferation, especially in the setting of hypoxia/re-oxygenation-induced cell stress.

We reported the preliminary results of percutaneous transluminal angioplasty (PTA) supported with a self-expanding stent (Wallstent) for the cervical internal carotid artery (i.c.) stenosis in 6 patients (7 lesions). All were male aged from 60 to 79 (mean 70.8). Three patients were symptomatic and 3 were asymptomatic. The procedure was attempted in patients with severe i.c. stenosis according to criteria of NASCET, ECST or ACAS studies and with high risk if carotid endarterectomy (CEA) were performed. In all cases, vascular access was from the femoral artery and angioplasty was performed without cerebral protection. Successful angioplasty was obtained in all cases with no mortality. Stenosis was improved from 82.7% (74-90%) to 17.4% (10-33%). Perioperative complications were seen in only one case with TIA during the postdilatation period, which was supposed to be due to a distal embolism. The preliminary results of PTA supported with self-expanding stent for severe i.c. stenosis were excellent. These results suggested that some patients with severe i.c. stenosis can be treated safely and effectively by stent-supported PTA. However, it is necessary to mark the indications clear and strict, and to follow up these lesions after the procedure, because of the possibility of perioperative ischemic complications and restenosis.

It is very important to make a prompt and accurate diagnosis and to commence pertinent treatment for patients suffering from acute cerebrovascular occlusive disease. Thirteen patients (mean age: 67.1 years) with basilar artery occlusion (BAO) were enrolled in this study. Dynamic computed tomography functional images (FID-CT) were analysed to determine whether this method could diagnose BAO in the acute phase. The functional images were categorized into 3 groups: (1) group A (n = 5) showed abnormalities on corrected mean transit time (cMTT) images and time-to-peak (TP) images in the territory of the posterior cerebral artery (PCA) and in the thalamus, (2) group B (n = 6) only showed abnormalities on TP images, and (3) group C (n = 2) had no abnormalities on either cMTT or TP images. The group C patients had poor time-density curves because of heart disease. Although the results may sometimes be false negative and this limitation should be kept in mind, FID-CT seem to be useful not only for defining patients who need angiography but also those who need thrombolytic therapy for acute BAO.

The aim of this study was to assess the pharmacokinetics and subsequent pharmacodynamic interaction of MPC-1304, a dihydropyridine Ca2+ antagonist, with other drugs in animal experiments. We measured the systolic blood pressure and heart rate of conscious spontaneously hypertensive rats implanted with battery-operated biotelemetry devices after combined administration of various drugs. Cimetidine (10 mg/kg) did not affect the reduction in systolic blood pressure and the increase in heart rate induced by MPC-1304, whereas it significantly increased the plasma concentration of a metabolite of MPC-1304 (M-1) compared to that detected when MPC-1304 was administered alone. When MPC-1304 was consecutively administered in combination with rifampicin (400 mg/kg) for 9 days, the plasma concentrations of MPC-1304 and of M-1 significantly decreased compared to those found when MPC-1304 alone was given. In spite of these reductions in plasma concentrations, rifampicin did not attenuate the hypotensive action induced by MPC-1304. When prazosin, reserpine, or methyldopa was administered in combination with MPC-1304, the hypotensive action was enhanced as compared to that by MPC-1304 alone or to that by the co-administered drug used alone (prazosin, reserpine, or methyldopa). Quinidine (10 mg/kg) affected neither the hypotensive action induced by MPC-1304 nor the plasma concentrations of MPC-1304 and M-1. These results indicate that cimetidine and rifampicin interact with MPC-1304 pharmacokinetically, without apparently changing the hypotensive action of MPC-1304, whereas quinidine does not affect the metabolism of MPC-1304, and that other hypotensive drugs, such as prazosin, reserpine, and methyldopa, potentiate the hypotensive action of MPC-1304.

The role of serotonin (5-HT) and protein kinases in the regulation of the beta-receptor induced by typical and atypical antidepressants was investigated. Treatment with either mianserin or maprotiline for seven days produced a significant decrease in the beta-receptor density measured 6h after the last dose. The reduction in beta-receptors disappeared within 24h. However, combined treatment of mianserin or maprotiline with either fluoxetine or 5-hydroxytryptophan significantly decreased beta-receptors even 24h after the last dose. Following treatment with p-chlorophenylalanine the reduction in beta-receptors induced by desipramine was reversible within 24h. These results demonstrate that an increase in the synaptic 5-HT availability may contribute to the prolongation of the beta-receptor down-regulation by antidepressants. The intraventricular infusion of 12-0-tetradecanoyl-phorbol-13-acetate (TPA), a potent protein kinase C (PK-C) activator for seven days caused a significant decrease in beta-receptors, while forskolin or dibutyryl cyclic adenosine monophosphate had no influence on the receptor. The TPA-induced and desipramine-induced decreases in beta-receptors were not additive, suggesting that a similar mechanism is involved. The infusion of the PK-C inhibitor 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7) caused an inhibition of the desipramine-induced decrease in beta-receptors. It is suggested that the beta-receptor down-regulation by antidepressants might be also regulated by PK-C through 5-HT-Ca2+-inositol-phospholipid systems.

The role of serotonin (5-HT) in the regulation of the beta-receptor density induced by long-term treatment with typical and atypical antidepressants was examined. Treatment with either mianserin (15 mg/kg, twice daily) or maprotiline (10 mg/kg, twice daily) for 7 days caused a significant decrease in the beta-receptor density, measured 6 h after the last dose, without a change in affinity. The reduction in beta-receptors disappeared rapidly (within 24 h). However, treatment with mianserin or maprotiline combined with fluoxetine, a selective 5-HT uptake inhibitor, significantly decreased the beta-receptor density even 24 h after the last dose. The combined administration of mianserin and 5-hydroxytryptophan (5-HTP) mimicked the effect of the combination with fluoxetine. Following pretreatment with p-chlorophenylalanine (PCPA) for 6 days, desipramine treatment for 3 days significantly decreased the beta-receptors 6 h after the last dose but this desipramine-induced decrease in beta-receptors was rapidly reversible (within 24 h). These results demonstrate that while intrasynaptic 5-HT levels are not a factor in the decrease in beta-receptors, they do play an important role in the preservation of the down-regulated state of the beta-receptor caused by antidepressants from rapid reversibility.