Association of the antagonism of von Willebrand factor but not fibrinogen by platelet alphaIIbbeta3 antagonists with prolongation of bleeding time.

BACKGROUND: The alphaIIbbeta3 antagonists inhibit platelet aggregation and are used as antithrombotic agents for cardiothrombotic disease. The present study investigates the correlation of inhibition of fibrinogen and von Willebrand factor (VWF) binding by alphaIIbbeta3 antagonists with the inhibition of platelet aggregation and prolongation of bleeding time (BT). METHODS: Inhibition of fibrinogen and VWF binding were assessed in a purified alphaIIbbeta3-binding assay. As an in vitro cell-based assay, platelet aggregation and VWF-mediated adhesion studies were performed using human platelets. In vivo effects on BT were measured using a template device in dogs at the same time as an ex vivo aggregation study was performed. RESULTS: In vitro studies demonstrated that the antiaggregatory effects of alphaIIbbeta3 antagonists correlate with their inhibition of fibrinogen binding, but not VWF. Interestingly, the effects of alphaIIbbeta3 antagonists on BT could be differentiated from the inhibition of platelet aggregation. Furthermore, this differentiation was strongly correlated with the different inhibitory potencies between fibrinogen and VWF binding, as well as that between VWF-mediated adhesion and aggregation. CONCLUSIONS: Our study provides novel evidence showing that the inhibitory effect of alphaIIbbeta3 antagonists on VWF, but not fibrinogen binding, correlates with their ability to prolong BT.

Impaired endothelial dysfunction in diabetes mellitus rats was restored by oral administration of prostaglandin I2 analogue.

We have previously reported that a decrease in hepatocyte growth factor (HGF), which has many protective functions against endothelial damage by high d-glucose, might be a trigger of endothelial injury. However, the regulation of vascular HGF in diabetes mellitus (DM) has not been clarified in vivo, although vascular disease is frequently observed in DM patients. In addition, our previous report revealed that a prostaglandin I(2) (PGI(2)) analogue prevented endothelial cell death through the induction of vascular HGF production in cultured human epithelial cells. Thus, in this study, we examined the effects of a PGI(2) analogue in the regulation of the local HGF system using DM rats. A PGI(2) analogue (beraprost sodium; 300 and 600 micro g/kg per day) or vehicle was administered to 16-week-old DM rats induced by administration of streptozotocin for 28 days. Endothelial function was evaluated by the vasodilator response to acetylcholine, and the expression of vascular HGF mRNA was measured by Northern blotting. Of importance, expression of HGF mRNA was significantly decreased in the blood vessels of DM rats as compared with non-DM (P<0.01). In addition, the in vitro vasodilator response of the abdominal aorta to acetylcholine was markedly impaired in DM rats. Importantly, the vasodilator response was restored by PGI(2) treatment in a dose-dependent manner (P<0.01), whereas N(omega)-nitro-l-arginine methyl ester inhibited the restoration of endothelial function. Of particular interest, vascular HGF mRNA and protein were significantly increased in the blood vessels of DM rats treated with PGI(2) as compared with vehicle. Similarly, an increase in HGF protein was also confirmed by immunohistochemical analysis. In addition, the specific HGF receptor, c-met, was also increased by PGI(2) treatment. Overall, this study demonstrated that treatment with a PGI(2) analogue restored endothelial dysfunction in DM rats, accompanied by the induction of vascular HGF and c-met expression. Increased local vascular HGF production by a PGI(2) analogue may prevent endothelial injury, potentially resulting in the improvement of endothelial dysfunction.

[A case of severe systemic edema in an elderly hypertensive patient with systemic lupus erythematodes during long-term treatment with anti-hypertensive drugs].

A 71-year-old woman receiving both angiotensin II receptor antagonist and calcium antagonist suffered severe systemic edema. She had been treated for essential hypertension with amlodipine for 2 years and candesartan for 3 months, and systemic lupus erythematodes (SLE) with steroids. During treatment, severe systemic edema appeared, mainly on her face, arms, and legs. At first, we suspected drug-induced edema by candesartan, so it was halted, but the edema still continued. We then considered amlodipine to be the culprit, and finally, the severe systemic edema disappeared after cessation of amlodipine. To control her blood pressure, we recommended candesartan, but 3 months late she suffered severe systemic edema again, thus the causative we drugs of her edema were thought to be both amlodipine and candesartan. Edema is a common symptom in elderly patients and we frequently observe drug-induced edema. In this case, there was underlying acceleration of blood vessel permeability induced by SLE and steroids and moreover, vasodilatation by candesartan and/or amlodipine further accelerated blood vessel permeability, and thus might have caused severe edema. It is very difficult to determine the cause of edema, especially in elderly patients, but we should consider not only one but also two or more drugs as being involved in drug-induced edema.

A family with von Hippel-Lindau disease revealed by pheochromocytoma.

Von Hippel-Lindau (VHL) disease is an inherited neoplastic disease characterized by a predisposition to develop retinal angiomas, central nervous system hemangioblastomas, renal cell carcinomas, pancreatic cysts and pheochromocytomas. Recently, we encountered three members of the same family who each had both VHL disease and pheochromocytoma. As in all three patients we suspected pheochromocytoma, the diagnosis of VHL disease should be considered. The possible presence of VHL disease was initially investigated in all three patients based on the presence of pheochromocytoma. A mutational analysis of the VHL gene revealed the presence of a missense mutation, consisting of a G to A transversion, at nucleotide 713 in all three patients. This germline point mutation in the VHL gene is often detected in type 2 VHL disease with pheochromocytoma. Genetic analysis seems to be useful for early detection of VHL disease, even when the formal criteria for diagnosis of this disease are lacking.

Clinical evaluation of the Elecsys beta-CrossLaps serum assay, a new assay for degradation products of type I collagen C-tlopeptides.

BACKGROUND: The Elecsys beta-CrossLaps serum assay measures type I collagen degradation fragments (beta-CTx) that contain the beta-isomerized octapeptide EKAHD-beta-GGR. We investigated the analytical performance of the assay and changes in beta-CrossLaps in patients with metabolic bone diseases. METHODS: The electrochemiluminescent sandwich immunoassay uses two monoclonal antibodies directed against different regions of the linear EKAHD-beta-GGR. RESULTS: beta-CrossLaps (beta-CTx) immunoreactivity was stable in serum and plasma stored at 4 degrees C for 24 h or at room temperature for 4 h, and it did not decrease appreciably in samples stored at -30 degrees C for 12 weeks. Nine cycles of repeated freezing-thawing did not affect serum beta-CTx. The intra- and interassay imprecision (CVs) for four samples was < or = 2.6% (n = 10) and < or = 4.1% (n = 10), respectively. The mean day-to-day biological variation (CV) was 20% in 10 postmenopausal women (n = 10 days). Serum beta-CTx and osteocalcin were correlated in patients with hyperparathyroidism (r = 0.796; P <0.0001; n = 28), chronic renal failure on hemodialysis (r = 0.784; P = 0.0003; n = 16), hypoparathyroidism (r = 0.950; P = 0.0001; n = 11), and pseudohypoparathyroidism (r = 0.987; P = 0.130; n = 4). Serum beta-CTx decreased by 47.4% +/- 8.8% (mean +/- SD) and 60.7% +/- 6.5% at 3 and 6 months, respectively, after initiation of estrogen replacement therapy in 34 women. These decreases were greater than the decreases in urinary excretion of deoxypyridinoline (31.8% +/- 3.9% and 38.1% +/- 4.4%, respectively) or pyridinoline cross-linked C-terminal telopeptide of type I collagen (15.9% +/- 3.9% and 16.9% +/- 4.6%, respectively). CONCLUSIONS: The Elecsys beta-CrossLaps serum assay provides a potentially useful tool for assessing bone resorption state, including its response to estrogen replacement therapy.

Contribution of Bcl-2, but not Bcl-xL and Bax, to antiapoptotic actions of hepatocyte growth factor in hypoxia-conditioned human endothelial cells.

Angiogenic growth factors play important roles in angiogenic responses, such as vasculogenesis and angiogenesis in response to hypoxia. A novel angiogenic growth factor, hepatocyte growth factor (HGF), has been reported to inhibit endothelial cell death. However, its molecular mechanisms are largely unknown. Thus, we studied (1) the effects of HGF on hypoxia-induced endothelial apoptosis and (2) the molecular mechanisms of the antiapoptotic actions of HGF in endothelial cells. Severe hypoxia increased the cell death rate in human aortic endothelial cells, whereas HGF significantly attenuated cell death. In addition, hypoxic treatment resulted in a significant increase in apoptotic cells, whereas HGF could attenuate apoptosis, accompanied by attenuation of the increase in caspase-3-like activity (P<0.01). Of importance, HGF significantly increased Bcl-2, an inhibitor of apoptosis, in a dose-dependent manner under normoxic and hypoxic conditions (P<0.01), whereas hypoxic conditions resulted in a significant decrease in Bcl-2. In contrast, HGF failed to affect Bcl-xL, which is also well known as an inhibitor of apoptosis under both normoxic and hypoxic conditions, whereas Bcl-xL was significantly decreased in endothelial cells exposed to hypoxia (P<0.01). No significant change in Bax, a promoter of apoptosis, was also observed in endothelial cells under hypoxia, whereas HGF did not affect BAX: Overall, this study demonstrated that HGF prevented endothelial cell death induced by hypoxia through its antiapoptotic action. The antiapoptotic mechanisms of HGF in hypoxia-induced endothelial cell death largely depend on Bcl-2, but not Bcl-xL and BAX:

Inhibition of neointima by angiotensin-converting enzyme inhibitor in porcine coronary artery balloon-injury model.

Because hepatocyte growth factor (HGF) stimulates growth of endothelial cells exclusively without replication of vascular smooth muscle cells, we hypothesized that HGF may play a role in cardiovascular disease. In human vascular smooth muscle cells, angiotensin II suppressed local vascular HGF production in a dose-dependent manner. Using a rat balloon-injury carotid artery model, we demonstrated that blockade of angiotensin II inhibited neointimal formation, accompanied by a significant increase in local HGF production. However, the relation of vascular HGF to endothelial function was not clarified. Moreover, it is important to test the hypothesis in animal models that are more similar to human restenosis. Thus, in the present study, we used a porcine coronary artery balloon-injury model to study the role of angiotensin II in regulation of the local HGF system in vivo. Expression of HGF mRNA was significantly decreased in balloon-injured coronary arteries versus intact vessels. An angiotensin-converting enzyme (ACE) inhibitor (perindopril) significantly inhibited neointimal formation after balloon injury compared with vehicle (P:<0.05). In addition, vasodilator response of balloon-injured coronary arteries to bradykinin was restored by perindopril treatment, whereas no vasodilator response was observed in balloon-injured vessels treated with vehicle. Vasodilator response of balloon-injured arteries induced by perindopril was completely abolished by N:(w)-nitro-L-arginine methyl ester. Of particular interest, vascular HGF mRNA was significantly increased in balloon-injured vessels treated with perindopril as compared with vehicle. Overall, the present study demonstrated that ACE inhibitor significantly inhibited neointimal formation, accompanied by significant improvement of endothelial dysfunction and a significant increase in local vascular HGF mRNA in vivo in a porcine coronary artery balloon-injury model. Given the strong mitogenic activity of HGF on endothelial cells, improvement of endothelial dysfunction by perindopril might be due to increased local HGF expression through enhancement of reendothelialization after balloon injury, in addition to its direct effect, ACE inhibition. Downregulation of the local vascular HGF system may play an important role in the pathogenesis of cardiovascular disease.

FK960, a novel potential anti-dementia drug, enhances high K(+)-evoked release of somatostatin from rat hippocampal slices.

We have demonstrated that FK960 [N-(4-acetyl-1-piperazinyl)-p-fluorobenzamide monohydrate], a novel putative anti-dementia drug of piperazine derivative, ameliorates memory deficits in a variety of animal models of dementia in rats and monkeys, and also augments long-term potentiation (LTP) in the mossy fiber-CA3 pathway in guinea-pig hippocampal slices. Our recent studies have further suggested that somatostatin activation could be a primary mechanism of the pharmacological action of FK960. To clarify the mode of action of FK960 on somatostatinergic neurotransmission, FK960 was examined for its effects on somatostatin release from rat hippocampal slices. FK960 significantly enhanced high K(+)-evoked release, but not basal release, of somatostatin with similar concentration-dependency to its LTP augmenting action. On the other hands, FK960 had no effects on the release of neurotransmitters such as acetylcholine, 5-HT, D-aspartate or GABA from hippocampal slices. Our results provide compelling evidence that FK960 exerts specific and facilitatory actions on neural mechanisms involved in the activity-dependent release of somatostatin from nerve terminals of the hippocampus. These results also strengthen the view that FK960 regulates cognitive functions and augments LTP through an activation of the somatostatinergic nervous system in the hippocampus.

In vivo transfer of human hepatocyte growth factor gene accelerates re-endothelialization and inhibits neointimal formation after balloon injury in rat model.

Although most therapeutic strategies to prevent restenosis are designed to inhibit vascular smooth muscle cell (VSMC) proliferation directly, VSMC proliferation might be indirectly inhibited by re-endothelialization, as endothelial cells secrete antiproliferative and antithrombotic substances. We hypothesized that application of an endothelium-specific growth factor to balloon-injured arteries could accelerate re-endothelialization, thereby attenuating intimal hyperplasia. In this study, we investigated in vivo gene transfer of human HGF that exclusively stimulated endothelial cells without replication of VSMC growth into injured vessels. Transfection of human HGF gene into rat balloon-injured carotid artery resulted in significant inhibition of neointimal formation up to at least 8 weeks after transfection, accompanied by detection of human immunoreactive HGF. Induction of re-endothelialization induced by overexpression of human HGF gene transfer into balloon-injured vessels is supported by several lines of evidence: (1) Administration of HGF vector. but not control vector, markedly inhibited neointimal formation, accompanied by a significant increase in vascular human and rat HGF concentrations. (2) Planimetric analysis demonstrated a significant increase in re-endothelialized area in arteries transfected with human HGF vector. (3) Induction of NO content in balloon-injured vessels transfected with human HGF vector was observed in accordance with the recovery of endothelial vasodilator properties in response to acetylcholine. As endogenous HGF expression in balloon-injured vessels was significantly decreased as compared with normal vessels, the present study demonstrated the successful inhibition of neointimal formation by transfection of human HGF gene as 'cytokine supplement therapy' in a rat balloon injury model.

Potential contribution of a novel antifibrotic factor, hepatocyte growth factor, to prevention of myocardial fibrosis by angiotensin II blockade in cardiomyopathic hamsters.

BACKGROUND: Because hepatocyte growth factor (HGF) prevented and/or regressed fibrosis in liver and pulmonary injury models, HGF may play an important role in the pathogenesis of fibrotic cardiovascular disease. Because angiotensin (Ang) II significantly decreased local HGF production, we performed (1) in vitro experiments using fibroblasts and (2) administration of an ACE inhibitor (temocapril) and an Ang II type 1 receptor antagonist (CS-866) to cardiomyopathic hamsters. METHODS AND RESULTS: In human fibroblasts, HGF significantly increased the production of matrix metalloprotease-1 (MMP-1) and urokinase plasminogen activator, whereas HGF also significantly attenuated the reduction of MMP-1 activity induced by Ang II. In contrast, HGF significantly decreased transforming growth factor (TGF)-beta mRNA stimulated by Ang II, whereas HGF also decreased basal TGF-beta protein level without affecting growth. Similarly, in rat cardiac fibroblasts, HGF inhibited the expression and production of TGF-beta, whereas HGF upregulated its specific receptor, c-met. Conversely, in vivo experiments revealed that administration of temocapril and CS-866 to cardiomyopathic hamsters resulted in a significant decrease in fibrotic area and increase in cardiac HGF concentration and mRNA (P<0.01), whereas cardiac concentration and mRNA of HGF were significantly decreased in cardiomyopathic hamsters. In contrast, mRNA expression of collagen III was markedly decreased by treatment with temocapril and CS-866. CONCLUSIONS: Here, we demonstrated that Ang II blockade prevented myocardial fibrosis in the cardiomyopathic hamster, accompanied by a significant increase in cardiac HGF. Overall, increase in local HGF expression may participate in the prevention of myocardial injury by Ang II blockade through its antifibrotic action.

Association of polymorphism in the promoter region of the apolipoprotein E gene with diastolic blood pressure in normotensive Japanese.

The epsilon4 allele of apolipoprotein E (APOE) is reported to be a genetic risk factor of atherosclerosis through hyperlipidemia and late-onset Alzheimer's dementia. A recent report showed that a genetic variant (A -491T) in the promoter region of the APOE gene increases the risk of Alzheimer's disease. In the present study, we examined whether these APOE polymorphisms were genetically involved in essential hypertension. Japanese hypertensives (n=180) with a family history of hypertension and normotensive controls (n=195, sex and age matched with hypertensives) were recruited from the outpatients of Osaka University Hospital, and an informed consent to participate in the study was obtained from each person. APOE polymorphisms were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The frequencies of the A -491 allele in hypertensives and normotensives were 0.98 and 0.97, respectively, and the TT/-491 genotype was not found in either group. No significant differences between hypertensives and normotensives were observed in allele frequencies in either APOE polymorphism; however, the mean diastolic blood pressure in normotensive subjects with AA/-491 was significantly higher than in the subjects with AT/-491 (p < 0.01). These results suggest that the presence of the APOE promoter polymorphism is not a major risk factor for hypertension but that it does have some minor effect on basal blood pressure variation.

Contribution of cardiovascular hypersensitivity to orthostatic hypertension and the extreme dipper phenomenon.

We report the case of a 68-yr-old woman who, upon standing, experienced dizziness in association with increased blood pressure (BP) and heart rate (HR). We made a diagnosis of orthostatic hypertension and examined the BP response to postural change using the head-up tilt test. Positional change resulted in a 20-mmHg increase in systolic BP and a 15-bpm increase in HR. A 24-h ambulatory BP recording showed daytime hypertension that decreased at night, along with a nocturnal decrease in HR. Based on these post-diagnostic results, the patient was rediagnosed as an extreme dipper with silent lacunar infarction as the only complication of orthostatic hypertension. We suggest that, in our patient, the mechanism of orthostatic hypertension was hypersensitivity of cardiovascular responsiveness to endogenous vasoconstrictors. This was evidenced by increased pressure sensitivity to isoproterenol as well as phenylephrine. We thus selected carvedilol, a beta-blocker with slight alpha-blocking action, and were more effective in abolishing the hypertension.

Angiogenesis induced by hepatocyte growth factor in non-infarcted myocardium and infarcted myocardium: up-regulation of essential transcription factor for angiogenesis, ets.

The feasibility of a novel therapeutic strategy using angiogenic growth factors to expedite and/or augment collateral artery development has recently entered the realm of treatment of ischemic diseases. Hepatocyte growth factor (HGF) is a novel member of endothelium-specific growth factors whose mitogenic activity on endothelial cells is very potent. Although it has been demonstrated that HGF is a potential angiogenic growth factor in in vitro culture systems, there is no direct in vivo evidence for the angiogenic activity of HGF in physiological conditions. In this study, we hypothesized that transfection of HGF gene into infarcted myocardium could induce angiogenesis, potentially resulting in a beneficial response to hypoxia. Human HGF gene or control vector driven by the SRalpha promoter was transfected into rat myocardium by the HVJ-liposome method. Four days after in vivo transfection of human HGF gene, there was a marked increase in human immunoreactive HGF as compared with control vector (P < 0.01). In myocardium transfected with HGF vector, a significant increase in PCNA-positive endothelial cells was observed, while few PCNA-positive endothelial cells were detected in both control-vector-transfected and untreated myocardium. The number of vessels around the HGF injection sites was significantly increased as compared with control vector or vehicle (P < 0.01). Angiogenic activity induced by the transfection of HGF vector was also confirmed by the activation of a transcription factor, ets, which is essential for angiogenesis. Furthermore, we studied the pathophysiological role of HGF in a myocardial infarction model. The concentration of endogenous HGF was significantly decreased in infarcted myocardium. Therefore, we hypothesized that transfection of HGF gene into infarcted myocardium could induce a beneficial response to the decreased endogenous HGF. Indeed, transfection of human HGF into infarcted myocardium also resulted in a significant increase in the number of vessels (P < 0. 01), accompanied by marked induction of ets binding activity and a significant increase in blood flow. Overall, the present results provide direct in vivo evidence for the induction of angiogenesis by transfection of the human HGF gene in rat non-infarcted and infarcted myocardium. The constant production of local HGF resulting from the transgene may be considered as an innovative therapeutic angiogenesis strategy for ischemic diseases such as myocardial infarction. Gene Therapy (2000) 7, 417-427.

In vivo evidence of the importance of cardiac angiotensin-converting enzyme in the pathogenesis of cardiac hypertrophy.

Cardiac angiotensin-converting enzyme (ACE) may play an important role in regulating cardiac hypertrophy. Angiotensin II (Ang II) stimulates cardiac hypertrophy as well as the production of extracellular matrix. However, it is still unclear whether Ang II exerts a direct effect on cardiac hypertrophy independent of its effect on blood pressure or the circulating renin-angiotensin system. Although ACE inhibitors and/or Ang II receptor antagonists have regressed cardiac hypertrophy, classic pharmacological experiments cannot exclude the contribution of hemodynamics and the circulating renin-angiotensin system. In vivo gene transfer provides the opportunity of assessing the effects of increased cardiac angiotensin in the intact animal without circulating angiotensin or blood pressure. Therefore, we used a "gain of function" approach to obtain local overexpression of cardiac ACE. Transfection of the human ACE vector into rat myocardium resulted in a significant increase in cardiac ACE activity (P<0.01). More interestingly, morphometry at 2 weeks after transfection revealed a significant increase in the thickness and areas of cardiac myocytes in hearts transfected with the ACE vector (P<0.01). In addition, transfection of the ACE vector also resulted in a significant increase in collagen content (P<0.01). This increase in cardiac hypertrophy was abolished by the administration of perindopril. Local transfection of the ACE vector into the heart did not result in systemic effects such as increased blood pressure, heart rate, or serum ACE activity. In summary, we have demonstrated that increased autocrine/paracrine angiotensin can directly cause cardiac hypertrophy independent of systemic factors and hemodynamic effects. This approach has important potentials for defining the role of autocrine/paracrine substances in cardiovascular disease.

Pancreatic Schwannoma: report of a case.

We present herein a case of solitary schwannoma of the pancreas and also review 26 previously reported cases from the English and Japanese literature. Primary schwannoma of the pancreas is a rare tumor. A 50-year-old female was discovered to have a large mass in the upper abdomen on ultrasonography. An examination by computed tomography (CT) scan, magnetic resonance imaging (MRI), and ultrasonography revealed a solid and cystic tumor in the left upper quadrant of the abdomen. A distal pancreatectomy with a splenectomy was performed to remove this tumor. A microscopic examination identified the tumor to be situated in the pancreas while it was composed of cells that originated from Schwann cells. Only 26 cases of pancreatic schwannoma have previously been reported in the English and Japanese literature. We describe in detail the characteristic findings based on image analyses, including CT scan, MRI, ultrasonography, and angiography, in these 26 cases.

Potential role of hepatocyte growth factor, a novel angiogenic growth factor, in peripheral arterial disease: downregulation of HGF in response to hypoxia in vascular cells.

BACKGROUND: Although hepatocyte growth factor (HGF), a novel angiogenic growth factor, plays an important role in angiogenesis, regulation of local HGF production under hypoxia has not yet been clarified in vascular smooth muscle cells (VSMC) and endothelial cells (EC). Thus, we have studied the role of HGF in hypoxia-induced endothelial injury and the regulation of local vascular HGF expression in response to hypoxia. METHODS AND RESULTS: HGF attenuated hypoxia-induced endothelial cell death. Importantly, hypoxic treatment of EC resulted in a significant decrease in local HGF production according to the severity of hypoxia and increased VEGF. Similarly, hypoxia significantly decreased in mRNA and protein of HGF and increased VEGF production in VSMC. In organ culture system, local HGF production was also significantly decreased by hypoxia (P<0.01). Downregulation of HGF by hypoxia is due to a significant decrease in cAMP, as hypoxic treatment decreased cAMP, a stimulator of HGF. Although active TGF-beta, a suppressor of HGF, was increased at 72 hours after hypoxic treatment, treatment of anti-TGF-beta antibody did not attenuate decreased HGF production. Finally, rHGF was intra-arterially administered into unilateral hind limb ischemia rabbits, to evaluate in vivo angiogenic activity. Of importance, a single intra-arterial administration of rHGF reduced severe necrosis due to ischemia in rabbit muscle, accompanied by a significant increase in angiographic score (P<0.01). CONCLUSIONS: Overall, these data demonstrated that hypoxic treatment of vascular cells significantly downregulated HGF production due to decreased cAMP, suggesting their potential roles in the pathophysiology of ischemic diseases. Moreover, administration of rHGF induced therapeutic angiogenesis, accompanied by improvement of necrotic changes in the ischemic hind limb model, as cytokine supplement therapy for peripheral arterial disease.

Hepatocyte growth factor (HGF) as a potential index of severity of hypertension.

Hepatocyte Growth Factor (HGF) is a mesenchyme-derived pleiotropic factor that regulates cell growth, cell motility, and morphogenesis of various cells, and is thus considered a humoral mediator of epithelial-mesenchymal interactions. We previously identified HGF as a novel member of the family of endothelium-specific growth factors. Moreover, the presence of a local HGF system (HGF and its specific receptor, c-met) has been demonstrated in vascular cells both in vitro and in vivo. HGF might contribute to the protection and/or repair of vascular endothelial cells injured by high blood pressure. If so, serum HGF level might be elevated in response to endothelial cell damage. To test this hypothesis, we measured serum levels of HGF in hypertensive and normotensive patients. Serum HGF concentration in hypertensive patients without any complications was significantly higher than that in normal subjects. Interestingly, serum HGF concentration in hypertensive patients with complications was significantly higher than that in either hypertensive patients without complications or normotensive subjects. Of importance, hypertensive patients treated with antihypertensive drugs showed the same level of serum HGF concentration as normotensive subjects. In contrast, serum HGF concentration in diabetic patients without hypertension was significantly lower than that in normal subjects, whereas serum HGF concentration in diabetic patients with hypertension was significantly higher than that in normal subjects. Moreover, serum HGF concentration in diabetic patients with hypertensive complications was even higher than that in diabetics without complications. This review discusses the possibility that HGF may be considered as a new index of the severity of hypertension.

Angiotensinogen gene-activating elements regulate blood pressure in the brain.

Although the angiotensinogen gene is a possible candidate as a determinant of hypertension, the molecular mechanisms of tissue angiotensinogen gene regulation have yet to be clarified. We identified essential transcription regulators of angiotensinogen production in the central nervous system using synthetic double-stranded oligodeoxynucleotides (ODNs) as "decoy" cis elements to block the binding of nuclear factors to promoter regions of the targeted gene. Using a gel mobility shift assay, angiotensinogen gene-activating element (AGE) 2 binding protein was detected in the brain nuclear extracts of both spontaneously hypertensive rats (SHRs) and normotensive Wistar Kyoto rats (WKYs). Importantly, the binding activity of AGE 2 and angiotensinogen mRNA level were significantly higher in the brain of SHRs than in that of WKYs. Using the decoy approach, we demonstrated a significant decrease in the blood pressure of SHRs by transfection of AGE 2 decoy, but not mismatched, ODNs into the lateral cerebroventricle, accompanied by a significant decrease in brain angiotensinogen concentration and mRNA, and angiotensin II level. That these effects, demonstrated herein, are due to central effects is confirmed by the fact that no changes in circulating levels of angiotensinogen or angiotensin II concentrations were observed. Notably, AGE 2 decoy ODNs did not decrease the blood pressure of WKYs. We conclude that the abnormal expression of AGE 2 binding protein in the central nervous system plays a crucial role in high blood pressure of a genetically hypertensive rat model.