Presence of low voltage area predicts atrial tachyarrhythmia inducibility with atrial burst pacing after pulmonary vein isolation

Background

Induction of atrial fibrillation (AF)/atrial tachycardia (AT) by atrial burst pacing following ablation procedure may reflect the presence of residual substrates in the atria that maintain AF. However, the relation between the inducibility and left atrial low voltage area (LVA) has not been established.

Methods

Fifty-nine patients (65 years old, 43 males) with persistent AF who underwent pulmonary vein isolation (PVI)-based ablation were studied. All patients underwent left atrial voltage mapping during sinus rhythm and atrial burst pacing after PVI. Atrial burst pacing was performed with 30-beat at an amplitude of 10V from the ostium of the coronary sinus; increasing from 240 to 320 ppm in steps of 20 ppm or failure to 1:1 atrial capture. Inducibility was defined as AF/AT lasting more than 5 minutes following burst pacing. Left atrial LVA and other co-variates were analyzed with regard to burst pacing positivity.

Results

AF/AT was induced by burst pacing in 23 patients (39%). Univariate analysis revealed that past history of stroke, CHADS2 score and presence of left atrial LVA were significantly associated with the inducibility of AF/AT. Multivariate analysis revealed that only the presence of LVA was associated with the inducibility (OR 1.5: per 10% increase; p=0.04). We focused on the relationship between the extent of LVA and burst positivity. AF/AT inducibility increased as low voltage area increased, and it was as high as 72.7% when low voltage area was more than 20% (P<0.05). Interestingly, induced arrhythmia type was AT rather than AF when low voltage area was more than 20%.

Conclusions

Presence of left atrial LVA is an independent predictor of atrial tachyarrhythmia inducibility after PVI in patients with persistent AF. A large amount of low voltage area is related to AT inducibility rather than AF.

Extent of LVA and burst positivity

Funding Acknowledgement

Type of funding source: None

Vascular density of superficial esophageal squamous cell carcinoma determined by direct observation of resected specimen using narrow band imaging with magnifying endoscopy

Observation of the microvasculature using narrow band imaging (NBI) with magnifying endoscopy is useful for diagnosing superficial squamous cell carcinoma. Increased vascular density is indicative of cancer, but not many studies have reported differences between cancerous and noncancerous areas based on an objective comparison. We observed specimens of endoscopic submucosal dissection (ESD) using NBI magnification, and determined the vascular density of cancerous and noncancerous areas. A total of 25 lesions of esophageal squamous cell carcinoma that were dissected en bloc by ESD between July 2013 and December 2013 were subjected to NBI magnification. We constructed a device that holds an endoscope and precisely controls the movement along the vertical axis in order to observe submerged specimens by NBI magnification. NBI image files of both cancerous (pathologically determined invasion depth, m1/2) and surrounding noncancerous areas were created and subjected to vascular density assessment by two endoscopists who were blinded to clinical information. The invasion depth was m1/2 in 20, m3/sm1 in four and sm2 in one esophageal cancer lesion. Mean vascular density was significantly increased in cancerous areas (37.6 ± 16.3 vessels/mm2) compared with noncancerous areas (17.6 ± 10.0 vessels/mm2) (P < 0.05). The correlation coefficients between vascular density determined by two endoscopists were 0.86 and 0.81 in cancerous and noncancerous areas, respectively. Receiver operating curve (ROC) analysis revealed that the area under the curve (AUC) of vascular density was 0.895 (95% CI, 0.804-0.986). For this ROC curve, sensitivity was 78.3% and specificity was 87.0% when the cutoff value of vascular density was 26 vessels/mm2. NBI magnification confirmed significant increases in vascular density in cancerous areas compared with noncancerous areas in esophageal squamous cell carcinoma. The rates of agreement between vascular density values determined by two independent operators were high.

The Na(+)/H(+) exchanger SM-20220 attenuates ischemic injury in in vitro and in vivo models

The aim of this study is to clarify whether the activation of a Na(+)/H(+) exchanger (NHE) is tightly concerned with neuronal and glial cell injury induced by ischemia using a selective NHE inhibitor, SM-20220 (N-(aminoiminomethyl)-1-methyl-1H-indole-2-carboxamide methanesulfonate). Two hours of hypoxia followed by 24 h of reoxygenation induced lactate dehydrogenase (LDH) release, a marker of cell membrane damage, in cultured neurons and glia derived from rats. SM-20220 significantly reduced LDH release in both cells in a concentration-dependent manner, and this effect was statistically significant at concentrations of more than 10(-8) mol/l for neurons and 10(-7) mol/l for glia. A standard NHE inhibitor, 5-(N-ethyl-N-isopropyl)-amiloride, also reduced LDH release in neurons at concentrations of more than 10(-7) mol/l. In a rat transient middle cerebral artery occlusion model, intravenous infusion of SM-20220 reduced cerebral infarction when the serum concentration of SM- 20220 was maintained at about 10(-7) mol/l. These results suggest that the activation of the NHE plays an important role in ischemic neuronal and glial cell injury, and NHE inhibitor may have good therapeutic value for the treatment of ischemic stroke.

Relationship between the neuroprotective effect of Na+/H+ exchanger inhibitor SM-20220 and the timing of its administration in a transient middle cerebral artery occlusion model of rats

The aim of this study was to determine the relationship between the neuroprotective effect of SM-20220 (N(aminoiminomethyl)-1-methyl-1H-indole-2-carboxamide methanesulfonate) and the timing of its administration in an experimental stroke model. Two hours of occlusion followed by 22 h of perfusion of the left middle cerebral artery (MCA) was performed by inserting a nylon thread into the MCA to occlude it, and pulling the thread to initiate reperfusion. Intravenous infusion of SM-20220 for 1 h reduced the infarct volume at doses of 0.2-0.8 mg/kg in a dose-dependent manner without causing changes in the systemic arterial blood pressure or blood gases, when SM-20220 administration was started 1 h after the onset of occlusion. Administration of SM-20220 at a dose of 0.4 mg/kg also reduced the edema formation induced by ischemia. In contrast, SM-20220 failed to reduce the infarction, even at 1.6 mg/kg, when administration was started 2 h after the onset of occlusion. Thus, the therapeutic time window of SM-20220 for this transient MCA occlusion model is 1 h. Daily administration of SM-20220 (0.4 mg/kg) for the 7 d following 1.5 h of middle cerebral artery occlusion reduced the infarct volume with statistical significance (p<0.05), showing that SM-20220 did not merely delay but prevented ischemic damage.

Na+/H+ exchange inhibitor SM-20220 attenuates leukocyte adhesion induced by ischemia-reperfusion

Leukocytes play a key role in ischemia-reperfusion-induced tissue injuries. It has been suggested that blocking the Na+/H+ exchanger improves ischemic injuries such as stroke. In this study, we investigated the effect of the Na+/H+ exchanger inhibitor SM-20220 (N-[aminoiminomethyl]- 1-methyl-1H-indole-2-carboxamide methanesulfonate) on leukocyte-endothelial cell interactions during ischemia-reperfusion. SM-20220 (0.3-1.0 mg/kg i.v.) given after ischemia significantly attenuated the leukocyte adhesion in the mesenteric postcapillary venules that was induced by transient superior mesenteric artery occlusion. At 60 min after reperfusion, the numbers of adherent leukocytes in groups treated with vehicle or SM-20220 (0.3 mg/kg) were 15.1+/-2.9 cells/100 microm/3 min and 3.0+/-0.7 cells/100 microm/3 min (p < 0.01), respectively. In a transient middle cerebral artery occlusion model, i.v. infusion of SM-20220 (0.4 mg/kg per hour) for 1 h, beginning 1 h after the start of occlusion, significantly reduced both the infarct size and the increase in brain myeloperoxidase activity, compared with the vehicle group (p < 0.01 and p < 0.05, respectively). In summary, this is the first evidence that the leukocyte adhesion to the endothelium that is induced by ischemia-reperfusion is attenuated by the inhibition of Na+/H+ exchanger activity in vivo. Our results suggest that Na+/H+ exchanger inhibitors may prevent ischemia-reperfusion injuries such as stroke partly through the attenuation of leukocyte-endothelial cell interactions.

Noradrenaline concentrations in human preovulatory follicular fluid exceed those in peripheral plasma

The concentrations of noradrenaline in preovulatory follicular fluid obtained from women undergoing in vitro fertilization were determined by high-performance liquid chromatography with fluorometric detection and compared with those in peripheral plasma obtained concurrently. All of the follicular fluid samples contained noradrenaline at concentrations substantially higher than those in the corresponding plasma samples. A positive correlation was found between noradrenaline levels in follicular fluid and plasma in each woman (n=11; r=0.952; p<0.001). However, there was no significant difference between noradrenaline concentrations in follicular fluid aspirated from follicles with or without an oocyte [mean+/-SEM, 0.207+/-0.002 ng/microl for follicular fluid samples with an oocyte (n=44), and 0.221+/-0.003 ng/microl for follicular fluid samples without an oocyte (n=13)]. The data indicate that noradrenaline accumulates in follicular fluid, supporting the physiological significance of noradrenaline in the local regulation of human ovarian functions.

Na+/H+ exchange inhibitor SM-20220 improves endothelial dysfunction induced by ischemia-reperfusion

Endothelial cells play an important role in the physiologic homeostasis of the cerebral circulation. Previously, we showed that the Na+/H+ exchanger (NHE) inhibitor SM-20220 (N-(aminoimino-methyl)-1-methyl-1H-indole-2-carboxamide methanesulfonate) improved ischemic brain injury. In this study, we investigated the effect of SM-20220 on cerebrovascular dysfunction after ischemia-reperfusion, focusing on the kinds of dysfunction that involved endothelial function. In cultured bovine brain microvascular endothelial cells (BBMCs), the IC50 value for the NHE activity of SM-20220 was 4 x 10(-8) M. SM-20220 also reduced the cell injury induced by hypoxia/aglycemia-reoxygenation in BBMCs, with statistical significance at 10(-7) M (P<0.05). Next, the effect of SM-20220 on disruption of the blood-brain barrier and cerebral blood flow were evaluated using transient middle cerebral artery (MCA) occlusion models. Intravenous infusion of SM-20220 (0.4 mg/kg per hour for 1 h) attenuated the extravasation of Evans blue, a blood-brain barrier disruption indicator, into cerebral tissue on the day after transient ischemia (P<0.05). The occlusion of the MCA decreased the cerebral blood flow in the MCA territory by about 20%, and only about 45% of the preischemic value was recovered at 1-h reperfusion. A bolus injection of SM-20220 (1 mg/kg, i.v.) improved the postischemic hypoperfusion by about 75%, without causing changes in the systemic blood pressure. These results indicate that the protective effect of NHE inhibitor on ischemic brain injury may be at least partially mediated by the prevention of endothelial dysfunction.

Stress responses during laparoscopy with CO2 insufflation and with mechanical elevation of the abdominal wall

STUDY OBJECTIVE

To compare the intensity of stress responses caused by laparoscopy combined with CO2 insufflation (CI) with those caused by mechanical elevation of the abdominal wall (MEA).

DESIGN

Prospective study (Canadian Task Force classification I).

SETTING

Tertiary care university hospital.

PATIENTS

Thirty-one women. Intervention. Laparoscopy, 16 with CI and 15 with MEA.

MEASUREMENTS AND MAIN RESULTS

Circulating levels of norepinephrine, epinephrine, cortisol, and interleukin (IL)-6 were compared in the two groups. Arterial partial pressure of CO2 (PaCO2) did not increase during laparoscopy by either method. Plasma norepinephrine and epinephrine levels increased after extubation in the MEA group but not in the CI group. Circulating cortisol levels in both groups increased during laparoscopy; mean intraoperative levels were higher in the CI group. Serum IL-6 levels increased after extubation in the MEA but not the CI group. Mean heart rate increased during laparoscopy in both groups, whereas blood pressure increased only in the CI group. More patients in the MEA group required postoperative analgesia.

CONCLUSION

Laparoscopy with MEA caused more pronounced adrenosympathetic and cytokine responses than that with CI when PaCO2 was maintained within the range of normocapnia.

SM-20220, a potent Na+/H+ exchange inhibitor, improves consciousness recovery and neurological outcome following transient cerebral ischaemia in gerbils

We studied the cerebroprotective effect of SM-20220 (N-(aminoiminomethyl)-1-methyl-1H-indole-2-carboxamide methanesulphonate), a newly synthesized Na+/H+ exchanger (NHE) inhibitor, in Mongolian gerbil global ischaemia. Transient cerebral ischaemia was induced by clipping both common carotid arteries for 30 min followed by 24h reperfusion. Intravenous administration of SM-20220 (0.3 or 1.0 mg kg(-1)) immediately after reperfusion significantly shortened the consciousness recovery time (P < 0.01). SM-20220 also improved the neurological outcome (McGraw's scale) after reperfusion. At the dose of 1.0 mg kg(-1), the mortality rate was significantly reduced at 24 h after reperfusion (P < 0.01). This study shows that NHE is involved in the aggravation of cerebral function, represented by consciousness recovery, and neurological outcome following transient forebrain ischaemia, and that its inhibitor may exert protective effects on post-ischaemic brain damage.

The effect of melatonin on in vitro fertilization and embryo development in mice

To examine the effect of melatonin on in vitro fertilization and embryonic development, mouse embryos after insemination in vitro were cultured in a physiological medium with or without melatonin. Melatonin increased the fertilization rate significantly at a concentration between 10(-6) and 10(-4) M (27.6 vs. 43.9 or 40.4%, P < 0.01). Furthermore, a significant increase in the rate of embryos reaching the four-cell stage (16.0 vs. 26.7%, P < 0.01), the eight-cell stage (12.1 vs. 25.8 or 23.5%, P < 0.01), and blastulation (8.9 vs. 23.5 or 17.5%, P < 0.01) was observed when the embryos were cultured in a medium containing 10(-8) or 10(-6) M melatonin. These results demonstrate that melatonin supports fertilization and early embryo development after in vitro fertilization.

Inhibition of kinin degradation on the luminal side of renal tubules reduces high blood pressure in deoxycorticosterone acetate salt-treated rats

1. To determine whether the antihypertensive response in deoxycorticosterone acetate (DOCA) salt-treated rats was mediated by kinins on the luminal side of renal tubules or in the circulation, selective urinary kininase inhibitors were administered to normal Brown Norway Kitasato (BN-Ki) rats and kininogen-deficient Brown Norway Katholiek (BN-Ka) rats. 2. Kinins were degraded by neutral endopeptidase (NEP) and carboxypeptidase Y-like kininase (CPY) in urine, but were inactivated mainly by angiotensin-converting enzyme (ACE) in the plasma. 3. Ebelactone B inhibited CPY, while poststatin inhibited CPY and NEP. 4. Daily administration of poststatin (5 mg/kg per day, s.c.) for 3 days reduced blood pressure (BP) in DOCA salt-treated BN-Ki rats, but not in BN-Ka rats. 5. Ebelactone B (5 mg/kg per day, s.c.) also reduced BP in BN-Ki rats, which was accompanied by increased urinary sodium excretion, but had no effect on BP in BN-Ka rats. 6. Lisinopril (5 mg/kg per day, s.c.) had no effect on BP in either rat strain. 7. Arterial kinin levels in BN-Ki rats increased significantly (2.2-4.6 pg/mL) with captopril (10 mg/kg, s.c.). However, arterial kinin levels that induced hypotension following the infusion of bradykinin (1000 ng/kg per min, i.v.) were 110-fold higher than endogenous arterial kinin levels attained following captopril. 8. These results suggest that inhibition of kinin degradation on the luminal side of the renal tubules may effectively attenuate hypertension.

Delayed treatment of Na+/H+ exchange inhibitor SM-20220 reduces infarct size in both transient and permanent middle cerebral artery occlusion in rats

SM-20220 (N-(aminoiminomethyl)-1-methyl-1H-indole-2-carboxamide methanesulfonate) is a Na+/H+ exchanger (NHE) inhibitor which has been shown to attenuate cerebral edema in the rat transient focal ischemia model. However, to date, the effect of SM-20220 on cerebral infarction has not been examined. The present experiments were designed to investigate these effects, using both transient and permanent middle cerebral artery (MCA) occlusion models in rats. A dose of 1 mg/kg given intravenously 30 min after the onset of transient MCA occlusion reduced the infarcted area. In the permanent MCA occlusion model, SM-20220 reduced the infarcted area when treatment was delayed for 5, 30 or 60 min after the onset of ischemia. The present results show that NHE has a crucial role in the pathogenesis of ischemic brain damage. This NHE inhibitor may be useful for treating stroke because of its effectiveness with both forms of ischemia and because of its postischemic administration.

Cerebroprotective properties of SM-20220, a potent Na(+)/H(+) exchange inhibitor, in transient cerebral ischemia in rats

The aim of this study was to investigate the contribution of the Na(+)/H(+) exchanger to cerebral ischemia using SM-20220 (N-(aminoiminomethyl)-1-methyl-1H-indole-2-carboxamide methanesulfonate), a newly synthesized compound. In in vitro experiments, we evaluated the inhibitory effect of SM-20220 on the Na(+)/H(+) exchanger in cultured neurons and glial cells. The IC(50) of SM-20220 in neurons and glial cells was 5 nM and 20 nM, respectively. To examine the in vivo effects of SM-20220 on brain injury, we used a transient middle cerebral artery occlusion model in rats. SM-20220 given intravenously 1 h after occlusion significantly reduced the extent of cerebral edema, Na(+) content and infarcted area in a dose-dependent manner. The results of the present study suggest that the Na(+)/H(+) exchanger is involved in the aggravation of brain edema and infarction, and its inhibitor may exert protective effects on post-ischemic brain damage.

Melatonin, its precursors, and synthesizing enzyme activities in the human ovary

The presence of melatonin (N-acetyl-5-methoxytryptamine) and its precursors, serotonin (5-hydroxytryptamine) and N-acetylserotonin, was demonstrated in extracts of human ovary using reverse-phase high-performance liquid chromatography coupled with fluorometric detection. In addition, activities of two melatonin-synthesizing enzymes, arylalkylamine N-acetyltransferase (NAT) and hydroxyindole-O-methyltransferase (HIOMT), were found in human ovary homogenates. The apparent Michaelis constants for the substrates of NAT and HIOMT in the human ovary were similar to those reported for the pineal glands of humans and other mammals. These findings strongly suggest that the human ovary, like the pineal gland, may synthesize melatonin from serotonin by the sequential action of NAT and HIOMT.

Removal of enterogenous cyst of the cervical spine through anterior approach

Enterogenous cyst is a cause of spinal cord compression. The cyst has been treated surgically through a posterior approach in spite of the location ventral to the spinal cord. We saw two patients who had recurrence at 1 and 3 years after partial removal through this approach. We removed the cyst at the level of the cervical spine in four patients totally or subtotally through an anterior approach. All patients improved neurologically, and there were no signs or symptoms of recurrence at follow-up of from 2 to 13 years (average, 7 years 3 months). It is reasonable to approach the cyst located ventrally to the spinal cord through the anterior route, where the relationship between the cyst wall and the spinal cord can be viewed directly.

Lectin histochemistry in rat liver fibrosis induced by heterologous serum sensitization

The localization of carbohydrates in rat livers with fibrosis induced by heterologous serum was examined by lectin histochemical and biochemical techniques. Twenty-four lectins were used to visualize the different carbohydrates in paraffin sections of normal and fibrotic liver tissues. No differences in staining patterns of these lectins were observed between normal and fibrotic livers in hepatocyte cell membranes including bile canaliculi, sinusoidal endothelial, or bile ductal cells. Kupffer cells strongly stained with Vicia villosa agglutinin (VVA) were seen only in the periportal zone of the normal liver, but they were observed in the periportal zone and scattered throughout the pseudolobular zone in the fibrotic liver. The cytoplasm of some hepatocytes was strongly stained by Bandeiraea simplicifolia lectin-I (BSL-I). BSL-I positive hepatocytes in normal liver were localized in the periportal zone, but those in the fibrotic liver were scattered in the periportal and perifibrous zones. After polyacrylamide gel electrophoresis of liver glycoproteins, differences in molecular sizes of BSL-I positive glycoproteins (79 and 81 kD) were detected by lectin blotting. Cell density of perifibrous BSL-I positive hepatocytes may be useful as a diagnostic parameter for liver fibrosis and/or cirrhosis. Two distinct staining patterns with twelve lectins were observed in fibrotic septa of the fibrotic liver. The fibrotic septa were stained with six characteristic lectins, and the centrilobular septa were stained with all these twelve of lectins. Histopathological assessment of the centrilobular fibrotic septa stained with these characteristic lectins may contribute to the diagnosis and prognosis of hepatic fibrosis.

Effect of catalase and thioredoxin addition to sperm incubation medium before in vitro fertilization on sperm capacity to support embryo development

OBJECTIVE

To determine whether addition of catalase and thioredoxin to sperm incubation medium before IVF improves sperm potential to support embryo development.

DESIGN

CD-1 mouse spermatozoa were preincubated without or with catalase or thioredoxin for 1 hour before IVF, and sperm motility parameters, fertilization rate, and embryo development were determined.

SETTING

A conventional laboratory setting.

INTERVENTION(S)

Mice were superovulated with pregnant mare serum gonadotropin and hCG. Eggs in cumulus oophorus were collected and used for fertilization with epididymal spermatozoa.

MAIN OUTCOME MEASURE(S)

Sperm motility parameters, fertilization rate, and embryo development.

RESULT(S)

Sperm motility parameters and fertilization rates were not affected by catalase treatment. However, the rates of blastocyst and hatching blastocyst formation when catalase-treated (16 micrograms/mL) spermatozoa were used were significantly higher than those observed with nontreated spermatozoa (44% versus 24%, 31% versus 2%, respectively). Addition of thioredoxin to preincubation media did not affect the percentage of motility and the fertilization rate but increased the rate of blastocyst formation to an extent similar to that triggered by catalase (2.7- and 3.3-fold, respectively).

CONCLUSION(S)

These results suggest that H2O2 produced in sperm suspensions before IVF reduces their potential to promote embryo development, that these toxic effects of H2O2 are latent, appearing mainly 3 to 5 days after IVF, and that catalase and thioredoxin are efficient agents to protect sperm potential to support embryo development.

Effect of sperm lipid peroxidation on fertilization

This study was aimed at determining, with homologous mouse gametes, whether a level of membrane lipid peroxidation insufficient to affect sperm motility parameters can alter sperm fertilizing potential. The addition of ferrous ions and ascorbic acid (Fe2+/ Asc) to mouse sperm suspensions increases the formation of thiobarbituric acid-reactive substances (TBARS), an indicator of lipid peroxide breakdown products, without significantly affecting the level of sulfhydryl groups. In the presence of Fe2+/Asc concentrations above > 0.4/2.0 mM, spermatozoa become immotile. However, at concentrations < or = 0.4/2.0 mM of Fe2+/Asc, i.e., conditions in which the TBARS formation is increased by < or = 4.6-fold over that of controls, motility remains unaffected for up to 3 hours. In the presence of 0.4/ 2.0 mM Fe2+/Asc, treated spermatozoa increase their fertilizing potential by 50%, as measured by the formation of two-cell embryos. This increase is not caused by improvements in sperm motility parameters (percentage, linearity, velocity, hyperactivation) or sperm capacitation. On the other hand, there is a significant increase in the capacity of mouse spermatozoa to bind to homologous zona pellucida. In conclusion, mild peroxidative conditions, that increase lipid peroxide formation 4.6-fold without significantly modifying free sulfhydryl groups and sperm motility parameters, improve the fertilizing potential of spermatozoa by increasing their binding capacity to zona pellucida.

Inhibitory effects of a phosphate diester of alpha-tocopherol and ascorbic acid (EPC-K1) on myocardial infarction in rats

The inhibitory effect of a phosphate diester of alpha-tocopherol and ascorbic acid (EPC-K1) was examined in myocardial infarction induced in rats, in comparison with a selective 5-lipoxygenase inhibitor, AA-861. EPC-K1 significantly reduced the infarct size at 24 and 48 h after ligation, whereas AA-861 reduced it only at 48 h after ligation. In in-vitro experiments, EPC-K1 inhibited not only superoxide anion generation (IC50 = 4.2 x 10(-5) M), but also acid phosphatase activity (IC50 = 2.4 x 10(-5) M) in rat polymorphonuclear leukocytes in a concentration-dependent manner, while AA-861 showed marginal effects on both actions. These results indicated that EPC-K1 induced cardioprotective effects by affecting neutrophil functions by inhibition of generation of superoxide-anion generation and acid-phosphatase activity. The mechanism of the reduction of the infarct size by EPC-K1 differed from that of AA-861, which latter inhibited 5-lipoxygenase and the formation of leukotriene B4.

Increase in vascular sensitivity to angiotensin II and norepinephrine after four-day infusion of 0.3 M sodium chloride in conscious kininogen-deficient brown Norway Katholiek rats

Kininogen-deficient Brown Norway Katholiek (deficient BN-Ka) rats excreted a small amount of kinin in their urine, compared with normal BN Kitasato (normal BN-Ki) rats from the same strain. Intraarterial (i.a.) infusion (6 ml/kg/hr) of conscious deficient BN-Ka rats with 0.15 M NaCl did not increase mean arterial blood pressure (MBP) [from 103 +/- 2 (pre) to 93 +/- 6 mmHg (day 4)] and did not cause sodium accumulation in the serum, cerebrospinal fluid or erythrocytes, but 0.3 M NaCl infusion significantly increased MBP from 104 +/- 3 (pre) to 130 +/- 5 mmHg (day 4) with increased sodium levels in the serum, cerebrospinal fluid and erythrocytes. Infusion of 0.3 M NaCl in normal BN-Ki rats neither increased MBP nor accumulated sodium. The dose-response curve of the increase in MBP for angiotensin II injection (i.a., bolus, 1-1000 pmol/kg) in 0.3 M NaCl-infused deficient BN-Ka rats shifted to the left by a factor of 10 compared with that in 0.15 M NaCl-infused deficient BN-Ka rats, and that for norepinephrine injection shifted to the left by a factor of 30. Normal BN-Ki rats did not show any enhancement in MBP elevation with 0.3 M NaCl. These results suggest that the sodium accumulation attributable to a lack of kinin generation may be related to increased vascular reactivity to angiotensin II and norepinephrine.

Ebelactone B, an inhibitor of urinary carboxypeptidase Y-like kininase, prevents the development of deoxycorticosterone acetate-salt hypertension in rats

Kininogen-deficient Brown Norway Katholiek rats (BN-Ka) excrete little urinary kinin, compared with normal rats of the same strain (BN Kitasato rats (BN-Ki)). Deoxycorticosterone acetate-salt treatment increased systolic blood pressure in both rats, but much faster in BN-Ka than in BN-Ki. Daily subcutaneous administration of ebelactone B (15 and 5 mg/kg/day), a rat urinary carboxypeptidase Y-like kininase inhibitor, significantly reduced systolic blood pressure in BN-Ki, but not in BN-Ka. This treatment significantly increased urinary Na+ excretion and reduced Na+ concentration in the erythrocytes in BN-Ki, but not in BN-Ka. An angiotensin-converting enzyme inhibitor, lisinopril (5 mg/kg/day s.c.), did not reduce the systolic blood pressure in either BN-Ki or BN-Ka. These results suggested that ebelactone B has promise as a preventive agent for the development of hypertension acting through the inhibition of urinary kinin degradation.

Effects of L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-1- benzopyran-6yl-hydrogen phosphate] potassium salt on cerebral energy state and consciousness recovery following transient forebrain ischemia in gerbils

Effect of L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H -1- benzopyran-6yl-hydrogen phosphate] potassium salt (EPC-K1, CAS 127061-56-7), a diester of alpha-tocopherol and ascorbic acid, on transient cerebral ischemia was studied in Mongolian gerbils. Cerebral energy metabolism and intracellular pH (pHi) were estimated employing in vivo 31P nuclear magnetic resonance (NMR) spectroscopy. Intraperitoneal injection of EPC-K1 (5 or 10 mg/kg) prior to ischemia significantly ameliorated pHi reduction in a dose dependent manner during ischemia. After reperfusion, energy and pHi recoveries were significantly faster in the EPC-K1 groups than in the control group. EPC-K1 (10 mg/kg) significantly reduced the extent of cerebral edema. Moreover, administration of EPC-K1 immediately after reperfusion significantly shortened the consciousness recovery in a dose dependent manner. The results suggest that EPC-K1 may exert protective effects on ischemic brain and may have therapeutic value in ischemic stroke.

Hypertension induced by a nonpressor dose of angiotensin II in kininogen-deficient rats

Brown Norway Katholiek rats with very low levels of plasma kininogens excreted a much smaller amount of kinin in the urine than normal rats of the same strain. The systolic blood pressure of 7-week-old kininogen-deficient rats (132 +/- 2 mmHg, n = 7) was not different from that of normal rats. Angiotensin II (Ang II) (20 micrograms/d SC) from 7 weeks of age for 2 weeks with a micro-osmotic pump caused significant increases in blood pressure (181 +/- 5 mm Hg, n = 7, 9 weeks old) in the deficient rats, although the same treatment induced no blood pressure increase in the normal rats. Also during this period, the deficient rats had significantly higher heart rates, tended to excrete less urinary sodium, and showed significantly higher sodium levels in serum, erythrocytes, and cerebrospinal fluid compared with the normal rats. Ang II increased urinary excretion of aldosterone in both deficient and normal rats (P < .05). Spironolactone treatment (50 mg/kg per day) for 7 days in deficient rats restored blood pressure and heart rate to normal levels and significantly reduced sodium levels in erythrocytes and cerebrospinal fluid. Subcutaneous infusion of bovine low-molecular-weight kininogen with an osmotic pump in Ang II-treated deficient rats induced significant reductions in blood pressure, heart rate, and erythrocyte sodium levels. By contrast, subcutaneous infusion of the bradykinin antagonist Hoe 140 in Ang II-treated normal rats induced a hypertensive response in parallel with significant increases in heart rate and erythrocyte sodium level. These results suggest that the lack of kinin generation observed in the kininogen-deficient rats may cause the hypertensive response during the administration of a nonpressor dose of Ang II mainly through sodium retention probably caused by aldosterone release.

Diuretic and natriuretic effect of ebelactone B in anesthetized rats by inhibition of a urinary carboxypeptidase Y-like kininase

Ebelactone B (EB) (10(-7)-10(-5) M) inhibited dose-dependently carboxypeptidase (CP) Y-like exopeptidase, one of the major kininases separated from rat urine, whereas it inhibited neither CPA, CPB or neutral endopeptidase (NEP). Degradation of bradykinin (BK) to BK-(1-8) in rat urine was completely inhibited by EB (10(-5) M) with the increased generation of BK-(1-7). Intraduodenal administration of EB (3 mg/kg) to anesthetized rats caused marked diuresis (by 110%) and natriuresis (130%), in parallel with the increase in urinary kinin levels (110%). Intravenous infusion of a BK antagonist, Hoe140 (3 mg/kg/hr), strongly blocked both EB-induced diuresis and natriuresis. EB may be a novel type of diuretic and natriuretic agent that acts by increasing urinary kinin levels.

High sensitivity to salt in kininogen-deficient brown Norway Katholiek rats

Brown Norway Katholiek rats, which have very low levels of plasma kininogens, excreted a much smaller amount of kinin in the urine than normal rats of the same strain. The systolic blood pressure of 7-week-old kininogen-deficient rats fed low (0.3%) NaCl diets (131 +/- 4 mm Hg, n = 12) was not different from that in normal rats. Two percent NaCl diets given from 7 weeks of age for 4 weeks caused rapid increases in blood pressure (167 +/- 4 mm Hg, n = 12, 9 weeks old) in deficient rats, although the same diets induced no blood pressure increase in normal rats. Urinary excretion of active kallikrein and prokallikrein remained constant in both rat groups throughout NaCl loading. During this period, the deficient rats secreted less urine (9 weeks old, P < .05) and less urinary sodium (11 weeks old, P < .05). Serum levels of sodium in deficient rats were higher (P < .05) than in normal rats at 9 weeks of age. Intracellular concentrations of sodium in the erythrocytes of deficient rats were higher (P < .05) than in normal rats throughout NaCl loading. Subcutaneous infusion of bovine low molecular weight kininogen with an osmotic pump in NaCl-loaded deficient rats induced a reduction (P < .01) in blood pressure and increases (P < .05) in urine volume and urinary sodium and kinin levels. By contrast, subcutaneous infusion of the bradykinin antagonist Hoe 140 or of aprotinin in NaCl-loaded normal rats induced a hypertensive response. This antagonist treatment reduced urine volume and urinary sodium. These results indicate that the lack of kinin generation observed in the kininogen-deficient rats was related through sodium retention to the hypertensive response to NaCl loading.

Poststatin, a novel inhibitor of bradykinin-degrading enzymes in rat urine

Incubation of bradykinin with rat urine resulted in the successive degradation of bradykinin to bradykinin-(1-8), bradykinin-(1-7) and bradykinin-(1-6). In contrast, in rat plasma, bradykinin was degraded via either bradykinin-(1-8) or bradykinin-(1-7) to bradykinin-(1-5). Phosphoramidon (1 mM) partially inhibited the degradation of bradykinin by rat urine, as well as the conversion of bradykinin-(1-7) to bradykinin-(1-6). D,L-2-Mercaptomethyl-3-guanidinoethylthiopropanoic acid (1 mM) and captopril (1 mM) did not have a significant effect on any of the degradation steps in rat urine. In contrast, all of the degradation steps in urine, namely, from bradykinin to bradykinin-(1-8), from bradykinin-(1-8) to bradykinin-(1-7) and from bradykinin-(1-7) to bradykinin-(1-6), were markedly inhibited by poststatin (1 mM), even though this compound was reported originally to be a novel inhibitor of post-proline cleaving enzyme. Poststatin (1 mM) did not inhibit the degradation of bradykinin in rat plasma. These results indicate that poststatin is an effective inhibitor of kinin-degrading enzyme in rat urine.

In vitro studies on the influence of L-ascorbic acid 2-[3,4-dihydro- 2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6yl-hy drogen phosphate] potassium salt on lipid peroxidation and phospholipase A2 activity

The effects of L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2- (4,8,12-trimethyltridecyl)-2H-1-benzopyran-6yl-hydrogen phosphate] potassium salt (EPC-K1, CAS 127061-56-7), a new compound for ischemia-reperfusion injuries, on lipid peroxidation and phospholipase A2 activity were studied in vitro using rat brain homogenates and human plasma. EPC-K1 inhibited phospholipase A2 activity in human plasma in a concentration-dependent manner (IC50 = 7.3 x 10(-4) mol/l), whereas a mixture of alpha-tocopherol and ascorbic acid did not exhibit this effect. In rat brain homogenates, EPC-K1 also inhibited lipid peroxidation in a concentration-dependent manner (IC50 = 2.3 x 10(-6) mol/l). alpha-Tocopherol was less active than EPC-K1. These properties of EPC-K1 suggest that EPC-K1 may prove useful in the treatment of ischemia-reperfusion injuries.

[A case of significant, non-neoplastic, ovarian hypertestosteronism]

A 24-year-old female with significant ovarian hypertestosteronism, who responded well both to gonadotropin releasing hormone (GnRH) agonist and cyclic administration of estrogen and gestagens in terms of suppressing circulating testosterone levels is reported. The patient's menstrual periods had been regular since menarche at the age of 12 until she became amenorrheic at the age of 20. She visited our facility in November 1988 after receiving three cycles of estrogen and gestagen replacement therapy from a previous physician which caused withdrawal bleeding. Clomiphen citrate reportedly failed to induce apparent ovulation. On her first visit with us, she was 160 cm tall weighing 47 kg with apparent hoarseness but not with hirsutism. Pelvic examination revealed significant clitoromegaly but otherwise normal external and internal genitalia. Laparoscopic examination disclosed that her uterus appeared to be normal with bilateral ovaries relatively small (4 x 4 x 3 cm) without tumorous or polycystic appearance. Histological examination of her ovaries obtained at laparoscopy showed several primary follicles with mild infiltration of the stromal cells. No thickened tunica albuginea or cystic formation were observed. These findings did not support either polycystic ovary or hyperthecosis. Serum testosterone (T) levels were extremely high (7.1 ng/ml), while serum androstenedione levels were only slightly above normal range (3.1 ng/ml). Urine 17-KS excretion was slightly increased (6.1 mg/day), while 17-OHCS output was within normal range (4.0 mg/day). Basal serum LH and FSH levels were within normal range and LH pulse frequency was reduced to 1 in 4 hours. Administration of dexamethasone 1 mg/day for 2 days did not suppress circulating T and free T levels but lowered serum cortisol concentration and urine excretion of 17-OHCS. Blood glucose and insulin levels were within normal limits and their responses to oral glucose administration were normal. Abdominal and pelvic ultrasonography and computed tomography as well as adrenal scintigraphy did not reveal any tumorous lesions in bilateral adrenals and ovaries. Administration of GnRH agonist, Buserelin 900 micrograms/day, suppressed circulating T concentrations to 0.7 ng/ml in 8 days, while it had no significant effects on DHEA and DHEA-S levels. After 16 weeks of Buserelin administration, ovulation was successfully induced by hMG administration. Cyclic estrogen and gestagen replacement therapy by Kaufmann's schedule for 2 cycles also suppressed serum T levels to normal, female range. Thus, the present case represents non-neoplastic, non-PCO, ovarian hypertestosteronism which responded well both to GnRH agonist and estrogen and gestagen replacement therapy in terms of lowering circulating T levels.

[The development of a new operating hysteroscopic fiberscope and its clinical application]

A new operating hysteroscopic fiberscope consisting of soft and rigid parts (4.8mm outer diameter) was developed with the support of Fuji Photo Optical Company. The working part of the scope can be divided into three sections: A flexible soft front section, a rotary rigid middle section and a flexible self retained semirigid rear section. With these functional parts the intrauterine target can be approached directly to perform the following operations. 1. Directed intrauterine biopsy. Thirty-five patients diagnosed as having endometrial polyp (13), submucous myoma (8), endometrial hyperplasia (4), endocervical polyp (3), endometrial carcinoma (2) and others (5) underwent direct biopsy with hysteroscopic control. No cervical dilatation or anesthesia was necessary. 2. Transcervical recanalization. In six cases of proximal tubal occlusion, a ureteral catheter or a percutaneous coronary balloon angiocatheter was introduced into the tubal ostium of the obstructed side to resolve the occlusion successfully with concomitant laparoscopy. 3. Hysteroscopic chorionic villus sampling. Chorionic villus sampling was performed with a ureteral catheter under direct hysteroscopic control and ultrasound guidance in eighteen pregnant women at from seven to fourteen gestational weeks. In fifteen cases, the samplings were performed satisfactory. 4. Removal of a lost IUD. Three cases of lost IUD underwent hysteroscopic removal without difficulty. Our results have proved that this scope is a very useful tool for intrauterine operations.

In vivo measurements of intra- and extracellular Na+ and water in the brain and muscle by nuclear magnetic resonance spectroscopy with shift reagent

The introduction of new paramagnetic shift reagents in the nuclear magnetic resonance (NMR) method has made it possible to distinguish intra- and extracellular ions in tissues or organs in vitro. We measured the intra- and extracellular 23Na and 1H in vivo in the gerbil brain and skeletal muscle by NMR spectroscopy employing the shift reagent, dysprosium triethylenetetraminehexaacetate (Dy[TTHA]3-). Without Dy(TTHA)3-, the 23Na and 1H signals were seen only as single peaks, but gradual intravenous infusion of Dy(TTHA)3- separated these signals into two peaks, respectively. The unshifted peaks reflected the intracellular 23Na and 1H signals, while the shifted peaks reflected the extracellular signals. In the brain spectra, an additional small peak, which represented intravascular signals, was detected and its intensity increased after injection of papaverine hydrochloride. The present method is advantageous over the microelectrode technique because of its nondestructiveness and its capability for obtaining intra- and extracellular volume information from measurements of the 1H spectra, the peaks of which reflect the intra- and extracellular water amounts. The intracellular Na+ increase associating with increased cellular volume after ouabain in the muscle was clearly visualized by this method. The technique is clearly of use for physiological and pathophysiological studies of organs.