Vasomotility and nitric oxide bioactivity of the bridging segments of the left anterior descending coronary artery

We compared bridging and nonbridging coronary artery segments with respect to the vasoconstrictor effect of acetylcholine. Bridging segments were hypersensitive to the constrictor effect of acetylcholine, and results suggest that the effect of nitric oxide on the acetylcholine-stimulated condition is decreased, or that the smooth muscle sensitivity to acetylcholine is increased.

Dependency on atrial electrophysiological properties of appearance of paroxysmal atrial fibrillation in patients with Wolff-Parkinson-White syndrome: evidence from atrial vulnerability before and after radiofrequency catheter ablation and surgical cryoablation

The pathogenesis of paroxysmal atrial fibrillation in patients with Wolff-Parkinson-White syndrome and the effects of elimination of accessory pathways on the appearance of atrial fibrillation are still controversial. Fifty-four patients with Wolff-Parkinson-White syndrome were classified into three groups: a No AF group (n = 24), patients without paroxysmal atrial fibrillation; an RF-AF Group (n = 12), patients with paroxysmal atrial fibrillation whose accessory pathways were eliminated using radiofrequency catheter ablation; and a Cryo-AF Group (n = 18), patients with paroxysmal atrial fibrillation whose accessory pathways were eliminated with surgical cryoablation. The electrophysiological characteristics of each group were evaluated prior to and following the elimination of their accessory pathways. As indices of atrial vulnerability, the presence of fragmented atrial activity and repetitive atrial firing zones were assessed. Inducibility of atrial fibrillation was significantly reduced following ablation of accessory pathways in the Cryo-AF group (83.3%-5.6%, P < 0.0001), while it was unchanged in the RF-AF group (83.3%-75%). In preablation studies, the effective refractory periods of the atrium in the RF-AF group and the Cryo-AF group were significantly shorter compared with the No AF group (204 +/- 18 ms, 197 +/- 16 ms vs 246 +/- 44 ms, respectively, P < 0.0001). Following ablation, the effective refractory period for patients in the Cryo-AF group was significantly prolonged compared with before ablation (197 +/- 16 ms to 232 +/- 24 ms, P < 0.0001). As a result of this prolongation of the effective refractory period of the atrium, the fragmented atrial activity and repetitive atrial response zones narrowed following ablation in the Cryo-AF group, but not in the RF-AF group. Therefore, the pathogenesis of atrial fibrillation in patients with Wolff-Parkinson-White syndrome may depend on the refractory period of the atrium rather than on the presence of accessory pathways.

Increased cytosolic free Mg2+ and Ca2+ in platelets of patients with vasospastic angina

This study was designed to test the hypothesis that the cellular metabolism of Ca2+ and Mg2+, which is important in platelet function, is abnormal in the platelets of patients with vasospastic angina. Cytosolic free Mg2+ concentration ([Mg2+]i) and Ca2+ handling were determined in the platelets of 24 patients with vasospastic angina and 24 control subjects by use of mag-fura 2 and fura 2. Platelet aggregation was also examined. Basal [Mg2+]i and cytosolic free Ca2+ concentration ([Ca2+]i) in platelets were significantly higher in patients with vasospastic angina than in control subjects. The amplitude of the [Ca2+]i transient induced by thrombin (0.03-1.0 U/ml) was significantly increased in the presence, but not in the absence, of extracellular Ca2+ in patients with vasospastic angina, as compared with controls. Therefore, the influx of Ca2+ across the plasma membrane may be accelerated in vasospastic angina. Thrombin (0.1-1.0 U/ml)-induced maximum aggregation response was significantly greater in patients with vasospastic angina than in controls. Results suggest that increased [Mg2+]i and altered Ca2+ handling by platelets may be associated with coronary vasospasm.

Expression of interleukin-8 correlates with vascularity in human gastric carcinomas

Interleukin (IL)-8 is a multifunctional cytokine that can stimulate the division of endothelial cells. We examined the expression of IL-8 mRNA using Northern blot analysis and in situ mRNA hybridization (ISH) and protein production using enzyme-linked immunosorbent assay and immunohistochemistry in 8 human gastric carcinoma cell lines and 39 gastric carcinomas and corresponding normal mucosa (34 surgical specimens and 5 biopsy specimens). Of the 8 human gastric carcinoma cell lines, 6 expressed 1.8-kb IL-8 mRNA and secreted various levels of IL-8 protein. The expression of IL-8 by TMK-1 cells was induced by exposure to IL-1 alpha, epidermal growth factor, and transforming growth factor-alpha, shown previously to be autocrine growth stimulators for human gastric carcinoma cells. In tumor tissues, most of the tumors (28 of 34 surgical specimens and 4 of 5 biopsy specimens) expressed IL-8 at higher levels than the corresponding normal mucosa. ISH and immunohistochemical analyses revealed that IL-8 mRNA and protein were localized in the cytoplasm of tumor cells. The number of blood vessels in the gastric carcinomas was determined by using antibodies against CD34. The level of IL-8 mRNA in the neoplasms strongly correlated with vascularization (Spearman correlation, r = 0.812; P = 0.001). The data suggest that IL-8 produced by tumor cells may regulate neovascularization and, hence, the growth and spread of human gastric carcinoma.

Extracellular and intracellular regulation of biliary lecithin hydrophobicity

Bromosulfophthalein and papaverine have been demonstrated to inhibit biliary lipid secretion without affecting secretion of bile salts in normal rats, so-called uncoupling. Bromosulfophthalein inhibits the capacity of intracanalicular bile salt micelles to induce biliary lipid secretion, and papaverine inhibits vesicular transport within the hepatocyte. We compared the effects of bromosulfophthalein and papaverine on biliary lipid secretion in normal Sprague-Dawley rats and Eizai hyperbilirubinuria rats. The fatty acyl chain saturation in biliary lecithin increased during bromosulfophthalein infusion and decreased during papaverine infusion in Sprague-Dawley rats. Bromosulfophthalein had no effect on biliary lipid secretion in Eizai rats, while papaverine induced uncoupling. The degree of fatty acyl chain saturation in biliary lecithin was unchanged during bromosulfophthalein infusion, but decreased with papaverine in Eizai rats. We deduce that selection of biliary lecithin species occurs at various points in the lipid transport pathway at intracellular and intracanalicular sites.

Effects of volume loading on pulmonary venous flow and its relation to left atrial functions

Although pulmonary venous (PV) flow is closely related to left atrial (LA) pressure dynamics, few investigators have discussed it in relation to LA functions, i.e., reservoir, conduit, and booster pump functions. We examined changes in PV flow rate, LA dimension, and left ventricular filling volume in 11 dogs, and assessed the effects of multistaged volume loading on PV flow and LA functions. Systolic PV flow rate (S) increased significantly and reached a plateau, reflecting a limited LA reservoir function. Diastolic PV flow rate (D) increased significantly with an increase in LA pressure. S/D ratio increased non-significantly from 0.87 +/- 0.07 before volume loading to 0.96 +/- 0.08 until S reached a plateau and then decreased to 0.76 +/- 0.08 (p < 0.05) because of a significant increase in D without an increase in S at the higher stages of volume loading. During atrial contraction, increases in LA active shortening and left ventricular filling volume were limited, indicating a limited LA forward ejection. The difference between PV flow rate just before and at the end of atrial contraction increased and correlated positively with left ventricular end-diastolic pressure (r = 0.57, p < 0.01). PV flow varies according to the degree of volume loading and reflects LA functions, which exhibit limited increases in response to volume loading.

Reduced incidence of Helicobacter pylori infection in young Japanese persons between the 1970s and the 1990s

Although the incidence of gastric carcinoma in Japan has declined in the past several decades, there is no information about trends in helicobacter pylori infection. The purpose of the study was to clarify trends in H. pylori infection and in histologic gastritis in young Japanese subjects evaluated between 1975 and 1978 (the 1970s) versus 1991 and 1994 (the 1990s). The prevalence of H. pylori infection and the grade of gastritis in biopsy specimens were evaluated in 173 young Japanese without localized lesions in the upper gastrointestinal tract. Findings in 75 specimens obtained from subjects in the 1970s were compared with those of 98 specimens obtained from subjects in the 1990s. The prevalence of H. pylori infection in the 1970s (54.7%) was significantly higher than that in the 1990s (28.6%) (p < 0.01). The grade of inflammation and the prevalence of both mucosal atrophy and intestinal metaplasia also were significantly higher in the 1970s than in the 1990s (p < 0.01 and p < 0.05). Our data thus show a trend toward a reduced prevalence of H. pylori infection and of histologically apparent gastritis (especially atrophic gastritis). This decrease may be linked to the reported decline of gastric carcinoma in Japan.

Staphylococcal septic arthritis: antibiotic and nonsteroidal anti-inflammatory drug treatment in a rabbit model

This study evaluated the effects of combining antibiotic therapy with the application of a nonsteroidal anti-inflammatory drug on the degradation of articular cartilage for an animal model of Staphylococcal septic arthritis. Rabbits were infected intra-articularly with Staphylococcus aureus. Antibiotic treatment started 18 hours after infection and continued for 7 days. Treatment with the nonsteroidal anti-inflammatory drug naproxen sodium started 24 hours before infection and continued for either 3 or 7 weeks. The cartilage matrix of uninfected and infected knees was quantified by analysis of glycosaminoglycan and collagen content. Three weeks after infection, the combined treatment of the nonsteroidal anti-inflammatory drug and antibiotics reduced the loss of glycosaminoglycan and collagen from the cartilage of the infected knee by 15 and 30%, respectively, compared with antibiotic treatment alone. Continuing treatment with naproxen sodium for 7 weeks reduced the loss of collagen by 50% when compared with antibiotic treatment alone. The longer period of treatment with naproxen sodium showed little further effect on the loss of glycosaminoglycan than that observed for the 3-week treatment. Treatment with this drug and antibiotics reduced swelling of the knee and levels of prostaglandin E2 in the synovial fluid. The data support the hypothesis that decreasing post-infectious inflammation by adding the drug to a standard antibiotic regimen reduces cartilage damage from Staphylococcal septic arthritis.

Bradykinin induced dilatation of human epicardial and resistance coronary arteries in vivo: effect of inhibition of nitric oxide synthesis

OBJECTIVE

To clarify whether endothelium derived nitric oxide contributes to exogenous bradykinin induced dilatation of human epicardial and resistance coronary arteries in vivo.

DESIGN

Quantitative coronary angiography and Doppler flow velocity measurements were used to determine the effects of the nitric oxide synthesis inhibitor, NG-monomethyl-L-arginine (L-NMMA), on bradykinin induced dilatation of the epicardial and resistance coronary arteries.

SETTING

Hiroshima University Hospital.

PATIENTS

20 patients (16 men and four women, mean (SD) age 56 (9) years) with angiographically normal smooth epicardial coronary arteries.

INTERVENTIONS

Serial infusions of bradykinin (0.5, 1.5, and 2.5 micrograms/min) were given into the left coronary ostium before and after L-NMMA infusion (60 mumol/min).

MAIN OUTCOME MEASURES

Epicardial coronary diameter, coronary blood flow, and coronary vascular resistance.

RESULTS

Bradykinin-induced epicardial coronary vasodilatation after L-NMMA (dilatation by 2.5 micrograms/min, 3.8(1.4)% in the proximal and 5.9(1.8)% in the distal segments, mean (SEM)) was less (p < 0.001, respectively) than before L-NMMA (11.7(2.5)% and 15.1(2.0)%, respectively). In contrast, L-NMMA did not affect the bradykinin induced increase in coronary blood flow and decrease in coronary vascular resistance.

CONCLUSIONS

Endothelium derived nitric oxide contributes to bradykinin induced dilatation of epicardial coronary arteries, but may be less important in coronary resistance vasodilatation.

Effect of cholestasis induced by organic anion on the lipid composition of hepatic membrane subfractions and bile in rats

Several organic anions inhibit the secretion of cholesterol and phospholipid into bile without affecting total bile acid secretion (uncoupling). The uncoupling induced by sulphobromophthalein (BSP) alters the fatty acid composition of biliary lecithin. The purpose of this study was to investigate the relationship between the lipid composition of bile and of liver subcellular membrane fractions during BSP-induced uncoupling. After depletion of the bile salt pool, rats fitted with a bile duct cannulus were infused with sodium taurocholate given either alone or with BSP. Bile was collected and liver microsomes and canalicular membranes were isolated for analysis of lipid composition. In bile, uncoupling increased the cholesterol/phospholipid ratio (C/P ratio) and the saturated/unsaturated fatty acid ratio (S/U ratio) in phosphatidylcholine. The C/P ratio was increased in the canalicular membrane, but the membrane phosphatidylcholine S/U ratio was decreased during uncoupling. In microsomes, the S/U ratio of membrane phosphatidylcholine was slightly increased, but the C/P ratio was unaffected during uncoupling. These results support the hypothesis that an increased secretion of hydrophobic phosphatidylcholine species from the canalicular membrane into bile reduces the proportion of hydrophobic phosphatidylcholine species in the canalicular membrane during uncoupling. The decreased contribution of hydrophobic phosphatidylcholine species may ameliorate the decrease in membrane fluidity resulting from the accumulation of cholesterol in the canalicular membrane and stimulate the synthesis of hydrophobic phosphatidylcholine species in the microsomes.

Differential effects of extracellular Mg2+ on thrombin-induced and capacitative Ca2+ entry in human coronary arterial endothelial cells

Receptor-mediated and capacitative Ca2+ entry are the primary Ca2+ entry pathways in endothelial cells (ECs). The mechanisms for Ca2+ entry via these pathways have not been fully elucidated. In this study, the effect of low and high external Mg2+ concentrations on these Ca2+ entry pathways was examined in human coronary arterial ECs. External Mg2+ concentration did not affect cytosolic free Mg2+ concentration. After exposure to thrombin in Ca(2+)-free medium, addition of Ca2+ to the medium caused a rise in cytosolic free Ca2+ concentration ([Ca2+]i), indicating thrombin-induced Ca2+ influx. Thrombin-induced Ca2+ influx was inhibited by not only low but also high external Mg2+ concentrations. After depletion of endoplasmic Ca2+ stores by thapsigargin, addition of Ca2+ to the medium induced an increase in [Ca2+]i, indicating capacitative Ca2+ entry. Capacitative entry was found to be accelerated by low external Mg2+ and inhibited by high external Mg2+ concentration. Results suggest that receptor-mediated Ca2+ influx requires external Mg2+ but is inhibited by increased external Mg2+ concentrations and that capacitative Ca2+ entry is reduced by external Mg2+ in human coronary arterial ECs.

A quantitative assessment of serum chylomicron by light scattering intensity: application to the intestinal fat absorption test

A novel fat absorption test to clarify the malabsorption syndrome was developed using a micronephelometric technique and compared with the classic conventional technique using 131I-triolein. An integrity of time-sequential light scattered from chylomicron-related turbidity in serum was determined between 0 and 300 min after butter fat load, being expressed in terms of the light scattering intensity (LSI). A good correlation was obtained between LSI and the serum level of chylomicron-triglyceride determined by an ultracentrifugation technique (r = 0.819, P < 0.001). The maximal LSI was consistently observed at 180 min after administration of a test meal in the normal group (n = 39), whereas the malabsorption syndrome group (n = 35) was distinctly different and could be further classified according to four patterns of LSI changes. In addition, an inverse correlation was found between this fat absorption test and the 131I-triolein absorption test. It was concluded that the micronephelometric technique which does not use a radionuclide is advantageous in its simple and safe evaluation of fat malabsorption syndrome.

Lack of effect of transmembrane gradient of magnesium and sodium on regulation of cytosolic free magnesium concentration in rat lymphocytes

The regulation of the intracellular concentration of Mg2+ ([Mg2+]i) is not fully understood. The level of Mg in lymphocytes is a good predictor of total body Mg status. We measured [Mg2+]i and total Mg in rat lymphocytes by using, respectively, the fluorescent Mg2+ indicator mag-fura-2 and atomic absorption spectrophotometry. The basal [Mg2+]i in rat lymphocytes was 328 +/- 23 micromol/l. An elevation to 5 mmol/l or the removal of extracellular Mg2+ did not affect [Mg2+]i. A reduction in extracellular Na+ did not influence [Mg2+]i for 60 min. The total Mg concentration in lymphocytes also remained stable. Results suggest that the permeability of the plasma membrane to Mg2+ is very low, and that Na+/Mg2+ exchange is not involved in the regulation of [Mg2+]i in rat lymphocytes.

[Prognostic survey of elderly patients with hypertension in the Chugoku and Shikoku districts--mortality and morbidity of cardiovascular complications. Study Group for Elderly Hypertensives in Chugoku and Shikoku Districts]

In order to examine the current status of antihypertensive drug therapy for elderly hypertensive patients, and the effect of clinical characteristics and drugs on their prognosis, 1669 hypertensive patients in the Chugoku and Shikoku districts, aged between 65 and 84 years, were enrolled and followed for 3 years. Of the 1669 patients enrolled, 1459 were selected for evaluation and 1127 patients were followed. Group A comprised 955 patients who had not suffered from any accident, group B comprised 139 patients who had suffered from a cerebral, cardiac, renal or other non-fatal accident, and group C comprised 33 patients who died. The mortality rate was 10.7/1000 patient.years and the morbidity rate was 55.6/1000 patient.years. The number of patients who received monotherapy was 736 (calcium channel blockers: #436, beta blockers: #100, angiotensin converting enzyme inhibitors: #80, diuretics: #64, alpha blockers: #16; others: #13). In group C, there were more male, and the patients were older and showed a higher level of serum creatinine concentration at enrollment compared with other groups. The use of diuretics and beta blockers tended to be low in this group. Among the three groups, however, there was no difference in blood pressure, heart rate or the use of each drug at enrollment. In summary, it is suggested that the different antihypertensive drug therapies die not influence the prognosis of elderly hypertensive patients.

Coronary segmental responses to acetylcholine and bradykinin in patients with atherosclerotic risk factors

This study was designed to elucidate the nature of coronary endothelial dysfunction in patients with hypertension and/or hypercholesterolemia and normal smooth coronary arteries by evaluating the coronary vascular responses to acetylcholine and bradykinin. The study included 19 patients (10 men; age [mean +/- SD] 61 +/- 9 years) with angiographically normal smooth coronary arteries and either hypertension (n = 7) and/or hypercholesterolemia (n = 13). Patients received acetylcholine (3 or 30 microg/min) infusions followed by bradykinin (0.5, 1.5, 2.5 microg/min) and nitroglycerin (200 microg/min) infusions into the left coronary ostium. Epicardial coronary artery diameters were measured by quantitative angiography. Angiography detected both vasoconstricted and dilated segments following acetylcholine infusion. Bradykinin significantly dilated both types of segments (p <0.001, respectively). However, bradykinin-induced dilation was significantly greater in segments exhibiting acetylcholine-induced vasodilation than in those exhibiting vasoconstriction (p <0.01 in the proximal portion and p <0.02 in the distal portion). Nitroglycerin-induced dilation was similar in all segments. These results suggest that coronary endothelial dysfunction may be a heterogeneous process in patients with coronary risk factors. Moreover, the mechanism underlying diminished endothelium-dependent dilation involves not only the muscarinic receptor, but also B2-kinin receptor.

Chromosome assignment of aberrant NotI restriction DNA fragments in primary hepatocellular carcinoma

DNA aberrations in human hepatocellular carcinoma (HCC) were studied by two-dimensional DNA electrophoresis analysis. Five intensified and 60 dwindling spots were detected recurrently in the two-dimensional profile which showed about 3000 restriction DNA fragments as distinctive spots. We assigned these aberrant spots to chromosomes, using the chromosome-assigned two-dimensional profile. Four of the five intensified, and 53 of the 60 dwindling spots were given chromosome assignments. Intensified spots were assigned to chromosomes 5, 6, 9 through 12, 16 and 18. Among the dwindling spots, the highest incidence of aberrations was found on chromosome 16, followed by 9 through 12 and chromosome 2. No aberrations were detected in chromosomes 7, 21, 22 or Y.

Angiotensin I-converting enzyme gene polymorphism and acute response to captopril in essential hypertension

Insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE) gene has been shown to be a determinant for serum ACE level and a marker for several cardiovascular diseases. We investigated whether the ACE gene can predict the therapeutic efficacy of ACE inhibitors in essential hypertensive patients. The response of blood pressure and plasma renin activity (PRA) 1 h after 50 mg captopril administration were evaluated in 82 inpatients with untreated essential hypertension (42 men, 40 women; mean age +/- SD: 52 +/- 13 years; range: 27 to 79 years) in relation to ACE genotypes. There were no differences in age, gender, blood pressure, and PRA in the basal conditions, among essential hypertensive patients with the II, ID, and DD genotypes (n = 36, 34, and 12, respectively). The acute responses of PRA and blood pressure to an ACE inhibitor were similar in the three groups. The blood pressure response was negatively correlated with baseline PRA (r = 0.497). These data suggest that PRA but not the I/D polymorphism of the ACE gene is a useful predictor of the short-term antihypertensive effects of ACE inhibitors.

Role of gastrin/CCK-B receptor in the regulation of gastric acid secretion in rat

The aim of this study was to investigate whether gastrin regulates morphological changes and alpha-subunit gene expression in parietal cells through the gastrin/CCK-B receptor on enterochromaffin-like cells by histamine release. Treatment with 100 mg/kg of YM022, a potent and selective gastrin/CCK-B receptor antagonist, for one week in rats did not alter mRNA levels of histidine decarboxylase or H+, K+-ATPase. However, parietal cell morphology predominantly changed to the resting form, although the serum gastrin concentration was significantly increased. Additional treatment with YM022 and oral omeprazole, 100 mg/kg, for one week markedly suppressed the increases of mRNA levels of histidine decarboxylase and H+, K+-ATPase and completely blocked the morphological transformation of the parietal cells to a stimulated form induced by treatment with omeprazole alone. This indicates that the morphological transformation of parietal cells to an activated form with a subsequent increase in H+, K+-ATPase synthesis caused by hypergastrinemia is mediated by increased histidine decarboxylase gene expression in enterochromaffin-like cells via gastrin/CCK-B receptors.

Reduction of plasma cholesterol levels and induction of hepatic LDL receptor by cerivastatin sodium (CAS 143201-11-0, BAY w 6228), a new inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, in dogs

The effects of cerivastatin sodium (BAY w 6228), a new type of inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, on plasma cholesterol concentrations and the induction of hepatic LDL receptors were investigated with beagle dogs and Hep G2 cells. Oral administration of cerivastatin (0.01, 0.03, and 0.1 mg/kg per day) for 3 weeks reduced plasma total and very low-density lipoprotein plus low-density lipoprotein (VLDL + LDL) cholesterol concentrations and increased hepatic LDL receptor binding activity in dogs. Scatchard plot analysis revealed a 1.9-fold increase in the maximum binding capacity of hepatic LDL receptors in cerivastatin-treated animals. Similar results were obtained by administration of pravastatin (1.0 and 5.0 mg/kg/day) for 3 weeks. Binding activity of the LDL receptor, as well as receptor mRNA and protein concentrations, were increased in a dose-dependent manner (0.01-1.0 microM) by exposure of Hep G2 cells to cerivastatin. The results suggest that cerivastatin reduces plasma cholesterol concentrations by increasing hepatic LDL receptor expression. The mechanism of lowering cholesterol concentration by cerivastatin was the same as with the other previously examined HMG-CoA reductase inhibitors, but the effects with cerivastatin were apparent at doses much lower than the effective doses of the other drugs. Cerivastatin, therefore, shows potential for clinical use as a potent and efficacious plasma cholesterol-lowering drug.

Change in blood pressure during altered sodium intake is not associated with calciotropic hormone level

1. We evaluated the effects of the dietary restriction of sodium chloride on blood pressure and systemic calcium metabolism in 19 in-patients with essential hypertension (11 men and 8 women, mean age 49.9 +/- 12.1 years). 2. All patients received a high-sodium diet (250 mmol/day) for 1 week, followed by a low-sodium diet (10 mmol/day) for another week. Intake of potassium (100 mmol/day) and of calcium (15 mmol/day) were kept constant throughout the study. 3. Sodium restriction significantly reduced the mean blood pressure (from 114.0 +/- 1.9 to 105.0 +/- 13.7 mmHg, P < 0.01). Urinary calcium excretion was significantly reduced (from 5.1 +/- 2.4 to 2.2 +/- 1.0 mmol/day, P < 0.01). 4. The change in mean blood pressure after sodium restriction was not correlated with a change in any parameter of calcium metabolism [whole blood ionized calcium, plasma intact parathyroid hormone, or 1,25-(OH)2 vitamin D3]. 5. Plasma renin activity during a regular sodium diet, an index of renin status, was significantly and inversely correlated with the change in blood pressure during sodium restriction, but not with any change in the parameters of calcium metabolism. 6. We conclude that sodium restriction reduces blood pressure and decreases urinary calcium excretion. However, we observed no significant role of extracellular calcium concentration or of calciotropic hormone concentration in the mechanism of sodium sensitivity.

Nocturnal decline in blood pressure is attenuated by NaCl loading in salt-sensitive patients with essential hypertension: noninvasive 24-hour ambulatory blood pressure monitoring

We investigated the effect of NaCl on the circadian blood pressure rhythm in patients with essential hypertension classified according to the presence or absence of salt sensitivity. We obtained 24-hour noninvasive ambulatory blood pressure measurements in 64 Japanese patients with mild to moderate essential hypertension who ate a low NaCl diet (50 mmol/d) for 1 week, followed by a high NaCl diet (340 mmol/d) for 1 week. Twenty-six patients whose mean blood pressure was increased more than 10% by NaCl loading were classified as salt sensitive. The remaining 38 patients were classified as salt resistant. The nocturnal decline in mean blood pressure was significantly smaller in salt-sensitive patients (8.3+/-1.0%) than in salt-resistant patients (11.5+/-0.9%) (P<.05) during a high NaCl diet but was similar in both groups during a low NaCl diet. There was no significant difference in the prevalence of the non-dipper pattern between groups on a low NaCl diet, but the prevalence of the non-dipper pattern was significantly higher in salt-sensitive patients than in salt-resistant patients on a high NaCl diet (0.57 versus 0.26, chi2=6.4; P=.02; odds ratio, 3.82). These findings suggest that the NaCl loading blunted the nocturnal decline in blood pressure in salt-sensitive patients but not in salt-resistant patients.

Expression of transforming growth factor alpha and epidermal growth factor receptor in human hepatocellular carcinoma

Transforming growth factor alpha (TGF-alpha) is thought to be involved in liver regeneration, cellular proliferation, and hepatocarcinogenesis. We have looked at the relationship between TGF-alpha and it's receptor, and have attempted to relate the expression of TGF-alpha and it's receptor to the differentiation of hepatocellular carcinoma (HCC) on serial sections of HCC. We examined immunohistochemically the expression of the TGF-alpha and of epidermal growth factor receptor (EGFR) proteins in the same area of 53 nodules (< 5 cm in diameter) of HCC obtained from patients. Immunoreactive proteins were visualized by using a biotin-streptoavidin system (LSAB Kil, Dako). TGF-alpha was strongly expressed in 29 of 53 (54.7%) nodules. Specimens strongly positive for TGF-alpha were found mainly in well-differentiated HCC, while specimens positive for EGFR were found mainly in poorly differentiated HCC (p < 0.05). In the tissues that stained weakly positive for TGF-alpha, the expression of EGFR differed significantly, according to the degree of HCC histologic differentiation (p < 0.05). These results led us to speculate that the expression of TGF-alpha and EGFR might be related to the pattern of histologic differentiation of HCC.

Gastric corpus IL-8 concentration and neutrophil infiltration in duodenal ulcer patients

BACKGROUND

The purpose of the present study was to examine the association between interleukin-8 (IL-8) in the gastric body due to Helicobacter pylori infection and histological gastritis, as well as elucidating the effect of acid secretion inhibitors on H. pylori associated body gastritis in duodenal ulcer patients.

METHODS

Twenty H. pylori-negative patients, 20 H. pylori-positive patients with chronic gastritis without peptic ulceration, and 20 H. pylori-positive duodenal ulcer patients (DU) were studied. Four biopsy samples were taken, each from the greater curvature of the antrum and body of the stomach. Biopsies were histologically investigated by ELISA to determine the density of H. pylori, the degree of neutrophil infiltration and the IL-8 concentration in the mucosa.

RESULTS

In the gastric mucosa of H. pylori-negative subjects, no IL-8 and hardly any neutrophil infiltration were observed. In contrast, enhanced IL-8 production and increased neutrophil infiltration were present in those infected with H. pylori. In H. pylori-positive patients, a significant correlation was observed between the IL-8 concentration and the degree of neutrophil infiltration, but no correlation was found in the body mucosa of those with DU. Twelve of 20 DU patients demonstrated hardly any neutrophil infiltration, despite the increased mucosal IL-8 content in the body. The administration of omeprazole in DU patients markedly increased mucosal neutrophil infiltration even though it did not cause any significant change in the H. pylori density and IL-8 concentration in the body. Although the effect of omeprazole was transient, a significant increase in neutrophil infiltration continued in comparison with the status before omeprazole administration in those subsequently undergoing maintenance treatment with H2-blockers.

CONCLUSION

In H. pylori-positive chronic gastritis, IL-8 concentration is enhanced in the mucosa of the body, and is associated with increased neutrophil infiltration. However, in DU patients, despite increases in body IL-8 concentration, neutrophil infiltration is reduced and the gastritis may be localized in the antrum.

Aging and severity of hypertension attenuate endothelium-dependent renal vascular relaxation in humans

Endothelial dysfunction may be related to cardiovascular risk factors, such as aging, hypertension, and atherosclerosis. We investigated whether aging and hypertension independently alter endothelial function in the renal circulation in humans in the absence of abnormalities in lipid and glucose metabolism. L-Arginine (500 mg/kg over 30 minutes) was intravenously administered to 33 patients with essential hypertension and 35 normotensive subjects. The L-arginine-induced increases in renal plasma flow (10.1+/-0.8% versus 15.8+/-0.9%, P<.05) and plasma cGMP (53+/-4% versus 82+/-5%, P<.05) were significantly smaller in patients with essential hypertension than in the normotensive subjects. Multivariate stepwise regression analysis showed that age (P<.0002) and the mean blood pressure (P<.0001) were independently and negatively correlated with the renal plasma flow response to L-arginine. Age (P<.002), mean blood pressure (P<.0001), and male sex (P<.05) were independently correlated with the L-arginine-induced increase in plasma cGMP. The peak change in plasma cGMP was significantly correlated with the L-arginine-induced increase in renal plasma flow (r=.63, P<.001). These findings suggest that aging and hypertension may independently impair endothelium-dependent renovascular dilation and that this effect may be caused at least in part by a decrease in nitric oxide production.

Effect of enprostil on omeprazole-induced hypergastrinemia and inhibition of gastric acid secretion in peptic ulcer patients

This study was performed to examine the effects of additional enprostil administration on hypergastrinemia and gastric acid suppression induced by omeprazole. Serum gastrin concentrations were measured in 10 peptic ulcer patients (six Helicobacter pylori-positive and four Helicobacter pylori-negative patients) before treatment, after two weeks of omeprazole (20 mg/day), and after two weeks of omeprazole and enprostil (50 micrograms/day). The additional acid inhibitory effect of enprostil was evaluated by 24-hr intragastric pH measurements in five healthy Helicobacter pylori-negative volunteers. After omeprazole treatment, the serum gastrin level of Helicobacter pylori-positive patients (3.5-fold of control) was markedly higher than that of Helicobacter pylori-negative patients (1.7-fold of control). Additional treatment with enprostil suppressed serum gastrin levels to 0.4-fold and 0.7-fold of omeprazole treatment levels in Helicobacter pylori-positive and Helicobacter pylori-negative patients, respectively. In healthy volunteers, median pH recorded during the nonmeal daytime interval increased significantly with additional enprostil. Thus, enprostil reduces undesirable omeprazole-induced hypergastrinemia, especially in Helicobacter pylori-positive patients, and effectively suppresses acid secretion.

Effect of Helicobacter pylori eradication on subsequent development of cancer after endoscopic resection of early gastric cancer

Although epidemiological studies strongly suggest an association between gastric cancer and Helicobacter pylori infection, there has been no clinical report indicating that cure of the infection prevents cancer. We conducted a nonrandomized H. pylori eradication trial in patients whose gastric cancer was removed by endoscopic resection (ER). We investigated the effect of treatment on the histopathology of the gastric mucosa, as well as on the incidence of metachronous gastric cancer during the long-term clinical and endoscopic follow-up. One hundred and thirty-two patients with early gastric cancer underwent ER and had H. pylori infection. Sixty-five (group A) were treated with omeprazole and antibiotics to eradicate the infection, and 67 (group B) were not. All patients were followed for 2 years post ER. After eradication treatment in group A, the disappearance of neutrophil infiltration in the antrum and body of the stomach was observed as was a decrease of the severity of intestinal metaplasia. Endoscopy after ER detected no new gastric cancers in these patients. After 3 years of follow-up, 6 (9%) of the 67 patients in group B had a new early-stage, intestinal-type gastric cancer endoscopically diagnosed. The above results suggest that H. pylori eradication may improve neutrophil infiltration and intestinal metaplasia in the gastric mucosa and inhibit the development of new carcinomas. This finding should be confirmed in a randomized, controlled trial.

Transcytotic vesicle fusion with canalicular membranes is modulated by phospholipid species: implications for biliary lipid secretion

Phospholipid species modulate bile metastability and the subselection of such species for biliary secretion occurs at the canalicular membrane. In this study, the role of phospholipid head groups and hydrophobic indices in transcytotic vesicle fusion with the canalicular membrane inner leaflet was investigated using rat canalicular membrane vesicles (CMV) and liposomes. The CMV were purified from Sprague-Dawley rat liver, and small unilamellar vesicles (SUV) of phosphatidylserine (PS), phosphatidylcholine (PC) and mixtures of PS/PC (1:1, 2:1 and 4:1) were labelled with 8 mol% of octadecyl rhodamine B chloride (R18). The PC species used in this study were egg yolk PC (EYPC), soybean PC (SBPC), dipalmitoyl PC (DPPC) and dilinoleoyl PC (DLPC). Fusion of SUV with CMV was initiated by the addition of a millimolar concentration of Ca2+ and the degree of fusion was estimated by the increase of R18 fluorescence. Ca(2+)-dependent fusion of SUV consisting of PS, and PS/PC (4:1) with CMV was observed (PS > PS/PC; 4:1), whereas no detectable fusion was evident between CMV and SUV of PC alone or PS/PC (1:1 or 2:1). The rank order of fusibility between CMV and SUV of PS/PC (4:1) containing various PC species was PS/DLPC > PS/SBPC > PS/EYPC > PS/DPPC. The hydrophobic index of PC as determined by high performance liquid chromatography (HPLC) was related closely to liposome fusibility (r = -0.88). These results suggest that transcytotic vesicle fusion with the canalicular membrane inner leaflet is regulated by the phospholipid hydrophobicity of the vesicles.

Immunocytochemical detection of p53 protein as an adjunct in cytologic diagnosis from pancreatic duct brushings in mucin-producing tumors of the pancreas

BACKGROUND

In cases of mucin-producing tumor (MPT) of the pancreas, a new clinical entity of pancreatic tumor, it has been reported to be difficult to distinguish adenoma from carcinoma preoperatively. This observation caused the authors to develop a new method of p53 immunocytochemistry using cytologic samples obtained by endoscopic retrograde pancreatic duct brushing (ERPDB).

METHODS

Fifteen cases of MPT (9 with carcinoma and 6 with adenoma) were examined. In all cases, histologic diagnosis was determined by surgery or autopsy. A wire with a small brush was pushed into the dilatated pancreatic duct detected by endoscopic retrograde pancreatography (ERP). Specimens obtained by brushing were prepared on slides and subsequently fixed with ethanol. Papanicolaou staining and p53 immunocytochemistry were performed simultaneously. The ability of conventional cytology to distinguish adenoma from carcinoma was compared with that of p53 immunocytochemistry.

RESULTS

Five of 9 cases (56%) with carcinoma of MPT were correctly diagnosed by Papanicolaou staining. Two of four cases, classified as benign by Papanicolaou staining, expressed p53 protein. Overall, 7 of 9 cases (78%) with carcinoma MPT were correctly diagnosed by Papanicolaou staining associated with p53 immunocytochemistry. In the cases with adenoma MPT, all cases were classified as benign by Papanicolaou staining and no case positive for p53 protein was encountered.

CONCLUSIONS

These results suggest that p53 immunocytochemistry as an adjunct in cytologic diagnosis using ERPDB may contribute to differentiating adenoma from carcinoma MPT of the pancreas preoperatively.

Extracellular Mg2+ inhibits capacitative Ca2+ entry in vascular smooth muscle cells

BACKGROUND

Agonist-induced Ca2+ entry is thought to be mediated by capacitative Ca2+ entry other than L-type Ca2+ channels in vascular smooth muscle cells (VSMCs). The mechanism for capacitative Ca2+ entry has not been fully elucidated. Our objective was to examine the effect of external Mg2+ on capacitative Ca2+ entry in cultured rat aortic VSMCs.

METHODS AND RESULTS

Three doses of external Mg2+ concentration (nominally 0, 1, and 5 mmol/L) were used. After exposure to 1 mumol/L, angiotensin II (Ang II) in Ca(2+)-free medium, addition of Ca2+ to the medium caused an increase in cytosolic free Ca2+ concentration ([Ca2+]i), indicating Ang II-induced Ca2+ influx. This Ca2+ influx was attenuated in cells preincubated with high external Mg2+ concentrations or with 1 mumol/L nifedipine. After VSMCs in Ca(2+)-free medium were exposed to 1 mumol/L thapsigargin, which inhibits the sarcoplasmic reticulum Ca(2+)-ATPase and depletes Ca2+ stores, addition of Ca2+ to the medium induced an increase in [Ca2+]i, indicating capacitative Ca2+ entry. This entry pathway was found to be independent of dihydropyridine-sensitive Ca2+ channels and inhibited by increased external Mg2+ concentration. External Mg2+ concentration did not influence Ca2+ efflux across the plasma membrane after stimulation with Ang II plus thapsigargin.

CONCLUSIONS

Results suggest that in VSMCs, capacitative Ca2+ entry is reduced by external Mg2+. This mechanism may explain in part the inhibitory effect of external Mg2+ on Ca2+ handling.

TP53 mutations in stage I gallbladder carcinoma with special attention to growth patterns

32 stage I cases of gallbladder carcinoma (GC) were examined to evaluate TP53 mutations with special attention to growth patterns. Their growth patterns were classified into two types: polypoid (P-type) and flat (F-type). 16 cases of GC were classified as P-type and 16 as F-type. p53 immunohistochemistry was performed using a mouse monoclonal anti-p53 antibody. Mutations in exons 5-8 were examined by polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) and direct sequencing. The incidence of p53 immunoreactivity was greater in the cases of F-type (11/16, 69%) than those in P-type (14/16, 25%) (P < 0.05). PCR-SSCP or direct sequencing revealed that TP53 mutations were detected in all cases positive for p53 protein. These results suggest that TP53 mutations may contribute to the carcinogenesis of the F-type GC, and than this pathway in the F-type may differ from that in the P-type GC.

The usefulness of gastric mass screening using serum pepsinogen levels compared with photofluorography

Chronic atrophic gastritis, which is though to be a high risk for gastric cancer, can be diagnosed by serum pepsinogen levels. We compared the usefulness of the measurement of pepsinogen levels and indirect photofluorography as indicators of gastric cancer in a mass screening involving 5,620 Japanese subjects (mean age: 60.1 years old; male : female = 2,268:3,352) in 1991 and 1992. Subjects with a serum pepsinogen I level below 30 micrograms/liter or a pepsinogen I/II ratio below 2.0 were considered to be at high risk of gastric cancer. The incidence of gastric cancer and the ratio of early cancers detected by pepsinogen levels (0.12%, 4/7) were similar to those detected by photofluorography (0.11%, 4/6). Our results showed that mass screening using pepsinogen levels was as useful as indirect photofluorography for the detection of gastric cancer in Japan. In addition, our results showed that the sensitivity of gastric mass screening was increased when the measurement of serum pepsinogen levels was combined with photofluorography.

Experimental hepatitis in neonatally thymectomized mice: transfer of disease and the role of T cells

Using neonatally A/J thymectomized mice, we have produced chronic hepatitis by administration of sublethal doses of Propionibacterium acnes and lipopolysaccharide (LPS). Our goal in this unique model was to evaluate the effector cell population required to generate chronic hepatitis by transferring spleen cells or splenic subpopulations derived from donor thymectomized mice with chronic hepatitis into congenic recipient nonimmunized thymectomized or sham-thymectomized animals. Several key observations were made regarding the ability to induce and to transfer disease. First, an inflammatory liver injury in neonatally thymectomized (NTx) mice was readily generated using sublethal doses of P. acnes and LPS. Second, the lesions were persistent and associated with the production of autoantibodies to liver-specific lipoprotein and anti-nuclear antibodies. Third, these features were not found in comparably injected nonthymectomized control A/J mice. Fourth, the same liver injury was transferred to neonatally thymectomized but otherwise naive mice by the transfer of donor spleen cells from affected mice previously induced to develop experimental hepatitis. Fifth, the transfer of this liver injury could not be achieved using T-cell-depleted spleen cells. Deletion of CD4+ T cells or CD8+ T cells by sensitized spleen cells resulted in suppression of the transferred liver injury. In contrast, transfer of nylon wool adherent splenic T cells induced severe hepatitis. These data suggest that the chronic liver injury induced in NTx mice by administration of P. acnes and LPS involves a breakdown in tolerance accompanied by the appearance of autoantibodies and that nylon wool adherent CD4+ and CD8+ T cells play important roles in the modulation of liver injury.

Significance of telomerase activity in the diagnosis of small differentiated hepatocellular carcinoma

Precise diagnosis of well-differentiated hepatocellular carcinoma (HCC) is sometimes difficult to establish. Telomerase activity was examined by telomeric-repeat-amplification protocol (TRAP) in 37 HCC nodules smaller than 3 cm in diameter, including 24 fine-needle-aspiration biopsy specimens, 22 non-tumor chronic-liver-disease tissues (9 chronic hepatitis and 13 liver cirrhosis) and 3 normal liver tissues. Telomerase activity was assayed by serially diluted samples and quantitated by using an internal telomerase assay standard (ITAS). Telomerase activity was detected in all HCC and in 11 of 22 non-tumor chronic-liver-disease tissues. Normal liver samples had undetectable telomerase activity. Cut-off level of telomerase activity for its practical usage in HCC diagnosis was tentatively set for 0.6 microg liver protein/assay at 10-cell equivalent activity of a gastric-cancer cell line, MKN-1. This level was twice the highest activity in non-tumor chronic liver disease therefore, telomerase activity in all non-tumor liver samples was below this level. The telomerase-positive incidence exceeding this cut-off level was 73% (11/15) in well-differentiated HCC, 94% (16/17) in moderately differentiated HCC and 100% (5/5) in poorly differentiated HCC. Well-differentiated HCC showed low positivity by other diagnostic markers. 21% by AFP, 0% by PIVKA-II and 13% by angiography. The detection of telomerase activity may thus be a useful additional tool for precise and early diagnosis of small differentiated HCC, even when diagnosis is inconclusive by conventional techniques.

Activation of MAP kinase cascade induced by human pancreatic phospholipase A2 in a human pancreatic cancer cell line

We have found that the growth of human pancreatic cancer cells MIAPaCa-2, induced by human pancreatic phospholipase A2 group I (hPLA2-I), is mediated via its specific receptor but not via its catalytic property. The present study showed that the activation of mitogen-activated protein kinase (MAPK) cascade in MIAPaCa-2 cells is induced by hPLA2-I: this digestive enzyme induced phosphorylation of MEK1/2, p44/42 MAPK and ATF-2, and the phosphorylation in the MAPK cascade was inhibited after the cells were pre-incubated with a selective inhibitor of MEK, PD98059. In addition, this inhibitor dose-dependently blocked the hPLA2-I-induced MIAPaCa-2 proliferation, suggesting that activation of the MAPK cascade is essential for the hPLA2-I-induced MIAPaCa-2 proliferation.

Significance of telomerase activity in the diagnosis of small differentiated hepatocellular carcinoma

Precise diagnosis of well-differentiated hepatocellular carcinoma (HCC) is sometimes difficult to establish. Telomerase activity was examined by telomeric-repeat-amplification protocol (TRAP) in 37 HCC nodules smaller than 3 cm in diameter, including 24 fine-needle-aspiration biopsy specimens, 22 non-tumor chronic-liver-disease tissues (9 chronic hepatitis and 13 liver cirrhosis) and 3 normal liver tissues. Telomerase activity was assayed by serially diluted samples and quantitated by using an internal telomerase assay standard (ITAS). Telomerase activity was detected in all HCC and in 11 of 22 non-tumor chronic-liver-disease tissues. Normal liver samples had undetectable telomerase activity. Cut-off level of telomerase activity for its practical usage in HCC diagnosis was tentatively set for 0.6 microg liver protein/assay at 10-cell equivalent activity of a gastric-cancer cell line, MKN-1. This level was twice the highest activity in non-tumor chronic liver disease therefore, telomerase activity in all non-tumor liver samples was below this level. The telomerase-positive incidence exceeding this cut-off level was 73% (11/15) in well-differentiated HCC, 94% (16/17) in moderately differentiated HCC and 100% (5/5) in poorly differentiated HCC. Well-differentiated HCC showed low positivity by other diagnostic markers. 21% by AFP, 0% by PIVKA-II and 13% by angiography. The detection of telomerase activity may thus be a useful additional tool for precise and early diagnosis of small differentiated HCC, even when diagnosis is inconclusive by conventional techniques.

Pentaerythritol tetranicotinate (niceritrol) decreases plasma lipoprotein(a) levels

We determined the most effective dosage of pentaerythritol tetranicotinate (niceritrol) to reduce plasma lipoprotein(a) [Lp(a)] levels in 44 Japanese patients (16 men and 28 women; mean age, 59.2 +/- 10.8 years) with hyperlipidemia types IIa, IIb, and IV. Patients received oral niceritrol at a dosage of 750 mg (3 tablets)/d for 8 weeks, followed by 1,500 mg (6 tablets)/d for 8 weeks. Administration of niceritrol 750 mg/d for 8 weeks decreased total and low-density lipoprotein (LDL) cholesterol in patients with type IIa hyperlipidemia and decreased triglycerides in patients with type IV hyperlipidemia, but did not affect Lp(a). However, niceritrol 1,500 mg/d for 8 weeks decreased Lp(a) in patients with initial Lp(a) levels greater than 30 mg/dL in addition to decreasing total and LDL cholesterol and triglycerides. These results suggest that the effective dosage of niceritrol to reduce the serum Lp(a) concentration in Japanese hyperlipidemic patients with a high Lp(a) level (> or = 30 mg/dL) is greater than 1,500 mg/d.

Time interval determination from left atrial appendage ejection flow in patients with mitral stenosis

The feasibility of determining the time interval from left atrial appendage (LAA) flow was examined using transesophageal Doppler echocardiography. Time intervals were compared between LAA flow and mitral flow patterns during late diastole in 8 patients with mitral stenosis and in 12 controls. The start of ejection flow from the LAA was later than the initiation of mitral flow, but the termination was same in both flows, indicating the contribution of LAA ejection to the latter half of the left atrial booster pump function. The pre-ejection time and the time interval from P-wave to end-ejection correlated significantly with left atrial dimensions (r = 0.55, and r = 0.70, respectively). The pre-ejection time, duration of the ejection flow from the LAA, and duration of mitral flow in the atrial contraction phase were significantly longer in patients with mitral stenosis (126 +/- 14 msec, 131 +/- 36 msec, and 167 +/- 28 msec, respectively) than in the controls (109 +/- 13 msec, 108 +/- 15 msec, and 141 +/- 17 msec, respectively). These results indicate that electrical conduction time from the right atrium to LAA can be estimated from the LAA ejection flow, and the time is related to the left atrial size. In patients with mitral stenosis, LAA contraction may contribute to left ventricular filling in the latter half of the atrial contraction phase.

[Evaluation of angiotensin I converting enzyme gene polymorphism in patients with essential hypertension and coronary artery disease]

We investigated the role of the insertion (I)/deletion(D) polymorphism in the angiotensin I converting enzyme (ACE) gene in the cardiovascular diseases. First, we studied 520 patients who had undergone coronary angiography: including 220 patients with acute myocardial infarction, 98 patients with effort angina pectoris (> 75% stenosis), 83 patients with vasospastic angina and 119 controls with normal coronary artery. There was no difference in the frequency of ACE gene I/D allele or genotype II, ID and DD among the four groups. Second, we studied the correlation between ACE gene I/D polymorphism and the clinical characteristics in patients with essential hypertension. The distribution of I/D allele and genotype were similar in 140 essential hypertensives and 83 normal controls. In patients with DD genotype, age at onset of hypertension was lower and left ventricular mass index was greater than those in patients with ID and II, although blood pressure levels and the severity of damage to other organs-were similar in the three groups. Further, 66 patients with essential hypertension were classified into 35 salt-sensitive and 31 salt-resistant patients according to changes in mean blood pressure during a week of low salt diet followed by a week of high salt diet. The frequency of I allele was significantly higher in the salt-sensitive group than in the salt-resistant group. In conclusion, ACE gene I/D polymorphism is not associated with coronary artery diseases. In patients with essential hypertension, the D allele was associated with early onset and left ventricular hypertrophy, while I allele was associated with salt sensitivity.

Effects of octreotide, a somatostatin analogue, on gastric function evaluated by real-time ultrasonography

BACKGROUND

Somatostatin exerts inhibitory effects on physiological functions in the gastrointestinal tract. The actions differ, however, depending on the test meal, dose, and other factors.

AIMS

To determine by use of ultrasonography and scintigraphy the effect of a somatostatin analog, octreotide, on gastric emptying and antral contraction.

SUBJECTS

Twenty healthy men; mean age 23.9 years

METHODS

Subjects were studied for 7 days, once after subcutaneous injection of octreotide, 50 microg, 5 min before the ingestion of a test meal and once after subcutaneous injection of placebo. Ten subjects received a liquid meal, 10 others received a solid meal. With the liquid meal, gastric emptying was measured 15 min after its ingestion and antral contraction was measured for 15 min by ultrasonography. With the solid meal, gastric emptying was measured both by ultrasonography (n = 10) and by simultaneous scintigraphy (n = 6), with antral contraction measured by ultrasonography for 5 h after ingestion of the meal.

RESULTS AND CONCLUSIONS

Octreotide given with a liquid or solid meal inhibited gastric emptying in healthy subjects. A significant suppression of antral contraction occurred only with a solid meal.

Relationship between insulin resistance and endothelium-dependent vascular relaxation in patients with essential hypertension

The infusion of L-arginine induces the production of nitric oxide and stimulates the immediate secretion of insulin. To examine the relationship between insulin resistance and endothelium-dependent vascular relaxation in patients with essential hypertension, we evaluated the renal and insulin responses to L-arginine, 500 mg/kg infused intravenously over 30 minutes, in 23 patients with mild essential hypertension who were neither obese nor diabetic and in 20 normotensive control subjects. We found no difference between the two groups in blood glucose or insulin in the fasting condition. The renovascular relaxation induced by L-arginine was significantly less in patients with essential hypertension than in normotensive control subjects. The increase in plasma cyclic GMP in response to L-arginine was lower in hypertensive patients than in normotensive subjects. Although the serum concentrations of glucose in response to L-arginine were similar in the two groups, the serum insulin response of the essential hypertensives was significantly higher than that of the normotensive subjects. In all subjects, the peak cyclic GMP response to L-arginine was significantly correlated with the peak delta glucose/ delta insulin ratio response to L-arginine (r = .69, P < .001). Findings suggested that an impairment of endothelium-dependent renal vascular relaxation and a reduced sensitivity to insulin are present in patients with essential hypertension. A link may be present between the abnormality of the L-arginine/nitric oxide/cyclic GMP pathway and insulin resistance in patients with essential hypertension.