Minoru Sanpei

Fukushima Medical University, Hukusima, Fukushima, Japan

Are you Minoru Sanpei?

Claim your profile

Publications (8)13.29 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Endothelin-1, a 21 amino acid polypeptide produced by vascular endothelial cells, has potent vasoactive properties. The purpose of this study was to estimate the effects of exogenous big endothelin-1 on fetal lamb circulation. Regional blood flow was measured by the colored microsphere technique during continuous infusion (60 minutes) of big endothelin-1, or saline (control), in 12 chronically instrumented sheep fetuses. After 60 minutes of big endothelin-1 administration, the fetal plasma endothelin-1 concentration increased significantly from 24.0 +/- 6.7 to 49.7 +/- 31.4 pg/mL (P = .018) without significant changes in fetal arterial blood gases. Continuous infusion of big endothelin-1 decreased blood flow in most organs except the brain and the heart. After the big endothelin-1 infusion, the blood flow to the brain significantly increased from 158 +/- 51 to 174 +/- 71 mL/min/100 g (P = .002); the blood flow to the heart also increased significantly from 171 +/- 95 to 200 +/- 112 mL/min/100 g (P = .001), respectively. Continuous infusion of endothelin-1 decreases blood flow in most of organs except the brain and the heart. It is likely that endothelin-1 plays an important role in fetal redistribution of blood flow.
    Obstetrics and Gynecology 11/2005; 106(4):818-23. · 4.80 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To measure plasma concentrations of endothelin (ET)-1, NO metabolites (nitrate/nitrite; NOx) and 6-keto PGF1 alpha (PGF1 alpha) in maternal and fetal sheep blood, and to evaluate the effects of big ET-1 on hemodynamic response, blood gases and NO and 6-keto PGF1 alpha production in near term fetal sheep. Hemodynamic parameters were measured during infusion of big ET-1 into the carotid vein in chronically catheterized fetal sheep on day 125 of gestation. Fetal arterial blood samples were obtained for ET-1, PGF1 alpha) and nitrate/nitrite (NOx) measurements. ET-1, NOx and PGF1 alpha plasma concentrations were all significantly higher in fetal compared with the maternal plasma. Big ET-1 significantly decreased fetal systolic and diastolic blood pressure and significantly increased fetal heart rate. Big ET-1 stimulated plasma PGF1 alpha), but not NOx , concentration. Circulatory regulating factors in the fetus were up-regulated. The effects of ET-1 on fetal hemodynamic response may be mediated via prostacyclin, but not via the NO pathway.
    Journal of Perinatal Medicine 02/2004; 32(6):495-9. · 1.95 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Various dysfibrinogenemias have been identified worldwide. This paper describes a case of dysfibrinogenemia recently identified in our laboratory. A 34-year-old pregnant woman without any clinical complaints was admitted to our hospital for delivery. She had an extremely low fibrinogen concentration as determined by the thrombin time method though immunoassay showed a titer within the reference range. Dysfibrinogenemia was suspected and further analyses were performed including on her family. Thrombin time was measured using human and bovine thrombin with and without calcium ion. Reptilase time was also measured. To identify the genetic mutation responsible for this dysfibrinogen, genomic DNA extracted from the blood was analyzed for mutation-rich regions in the fibrinogen gene. The subject, her mother and her two infants showed the same pattern of results while her father showed a regular pattern. Thrombin time calculated using both human and bovine thrombin and reptilase time was elongated in the propositus. The extent of the elongation was decreased in the presence of calcium ion. DNA sequencing showed heterogeneous fibrinogen gammaR275C mutations in the propositus, mother and two children. The father showed no mutation. A case of dysfibrinogenemia gammaR275C without any clinical symptoms was found by routine coagulation testing and was genetically identified.
    Clinica Chimica Acta 12/2002; 325(1-2):151-6. · 2.85 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Various dysfibrinogenemias have been identified worldwide. This paper describes a case of dysfibrinogenemia recently identified in our laboratory. Patient: A 34-year-old pregnant woman without any clinical complaints was admitted to our hospital for delivery. She had an extremely low fibrinogen concentration as determined by the thrombin time method though immunoassay showed a titer within the reference range. Dysfibrinogenemia was suspected and further analyses were performed including on her family. Thrombin time was measured using human and bovine thrombin with and without calcium ion. Reptilase time was also measured. To identify the genetic mutation responsible for this dysfibrinogen, genomic DNA extracted from the blood was analyzed for mutation-rich regions in the fibrinogen gene. Results: The subject, her mother and her two infants showed the same pattern of results while her father showed a regular pattern. Thrombin time calculated using both human and bovine thrombin and reptilase time was elongated in the propositus. The extent of the elongation was decreased in the presence of calcium ion. DNA sequencing showed heterogeneous fibrinogen γR275C mutations in the propositus, mother and two children. The father showed no mutation. Conclusions: A case of dysfibrinogenemia γR275C without any clinical symptoms was found by routine coagulation testing and was genetically identified.
    Clinica Chimica Acta 01/2002; · 2.85 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: The aim of this study was to illuminate the mechanism of a redistribution of blood flow in fetuses. Nitric oxide (NO) is now known to play important functional roles in the vasculature. We measured plasma nitrate (the metabolites of nitric oxide) concentrations in maternal and fetal sheep at term, and compared the effect of NO donors on isolated carotid and renal arteries from fetuses.Methods: (1) Blood samples were taken from maternal and fetal arteries in sheep at 132 ± 2 days’ gestation, and were collected for nitrate determination with Griess reagent. (2) Rings of carotid and renal arteries with intact endothelium from fetal sheep were positioned in organ chambers filled with Krebs-Henseleit solution (37°C) bubbled with 5% CO2 in air (pH: 7.4) and isometric tension was recorded. Concentration-response relationships to sodium nitroprusside (SNP), nitroglycerine (NTG) and diethylamine nitric oxide (DEA/NO) with pretreatment NO scavenger, oxyhemoglobin (10–5 M), and vehicle were determined.Results: (1) Plasma nitrate levels were significantly higher in fetuses than in maternal sheep. (2) Nitric oxide donor concentrations dependently inhibited in phenylepherine-precontracted carotid and renal arteries. The relaxation of both rings was attenuated by previous treatment with oxyhemoglobin. Nitric oxide sensitivity was greater in carotid arteries than in renal arteries. The order of potency was SNP > NTG > DEA/NO in the two types of arteries.Conclusion: These observations indicate that NO may play an important role in the redistribution of blood flow in fetuses.
    Journal of Obstetrics and Gynaecology Research 01/2002; 28(2):112-114. · 0.84 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this study was to investigate the effects of prolonged (24-h) non-acidemic hypoxemia on plasma endothelin-1 and atrial natriuretic peptide (ANP) in fetal goats. During continuous infusion of nitrogen into the maternal trachea, fetal plasma endothelin-1 and ANP levels were measured in nine chronically instrumented goat fetuses at 117-129 days' gestation. Endothelin-1 and ANP were measured by radioimmunoassay. Fetal arterial pO(2) decreased significantly from 23.1 +/- 1.0 mmHg (control) to 15.2 +/- 0.9 mmHg during the first 2 h of hypoxemia and to 15.7 +/- 1.1 mmHg at the end of the experimental period of hypoxemia. The plasma endothelin-1 concentration increased from 10.6 +/- 1.9 pg/ml to 20.4 +/- 4.3 pg/ml (p < 0.05) during the first 2 h and was 19.7 +/- 2.4 pg/ml (p < 0.01) at the end of the experimental period. The plasma ANP concentration also increased, from 20.3 +/- 5.5 pg/ml to 23.0 +/- 4.7 pg/ml in the first 2 h and then to 58.0 +/- 8.8 pg/ml (p < 0.05) at the end of the experimental period. There was a significant negative correlation between fetal plasma endothelin-1 and pO(2), but no significant correlation was found between fetal plasma ANP and pO(2). Prolonged non-acidemic hypoxemia induces a continuous increase in fetal plasma endothelin-1 and ANP levels. Fetal plasma ANP increases time-dependently but endothelin-1 remains constant during hypoxemia.
    The Journal of Maternal-Fetal Medicine 12/2001; 10(6):409-13.
  • American Journal of Obstetrics and Gynecology - AMER J OBSTET GYNECOL. 01/2001; 185(6).
  • American Journal of Obstetrics and Gynecology - AMER J OBSTET GYNECOL. 01/2001; 185(6).

Publication Stats

9 Citations
13.29 Total Impact Points

Institutions

  • 2004–2005
    • Fukushima Medical University
      • • Division of Medicine
      • • Department of Obstetrics and Gynecology
      Hukusima, Fukushima, Japan