Study on the factors inducing hypersensitivity of the blood vessels to pressor substances in toxemia of pregnancy
| Project/Area Number |
60570769
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Obstetrics and gynecology
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| Research Institution | Saitama Medical Center, Saitama Medical College (1986)
The University of Tokyo (1985) |
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Principal Investigator |
SATOH Kazuo Saitama Medical Center, Saitama Medical College Professor, 医学部, 教授 (80010180)
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| Co-Investigator(Kenkyū-buntansha) |
BABA Kazunori Saitama Medical Center, Saitama Medical College Assistant, 産婦人科, 助手 (30181035)
KOJIMA Toshiyuki Saitama Medical Center, Saitama Medical College Lecturer, 産婦人科, 講師 (90153535)
TAKEDA Satoru Saitama Medical Center, Saitama Medical College Lecturer, 産婦人科, 講師 (20143456)
KINOSHITA Katsuyuki Saitama Medical Center, Saitama Medical College Assistant Professor, 産婦人科, 助教授 (80010354)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1986: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1985: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | Toxemia of pregnancy / <Na^+> - <K^+> ATPase / Na利尿因子 / PG【I_2】 / 血圧 |
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| Research Abstract |
Attention has recently been focused on hypersensitivity of the blood vessels to pressor substances as pathogenesis of toxemia of pregnancy. Natriuretic factor is reported to be involved in regulation of Na retention which is suggested to be one of the causative factors leading to essential hypertension. Natriuretic factor has the stimulatory effect on Na secretion from the kidney by inhibition of <Na^+> - <K^+> ATPase, through which, on the other hand, the increased intracellular Na retention may be brought about in the arterial wall. Consequently, increased intracellular Ca resulting from <Na^+> - <Ca^(++)> exchange reaction may induce hypersensitivity of the blood vessels to pressor substances. Secretion of natriuretic factor may be stimulated during pregnancy through increased body fluid and Na retention, which might result in toxemia of preganacy. Measurement of the activity of <Na^+> - <K^+> ATPase inhibitor in the blood by Hamlyn's method revealed that its activity in toxemia of pregnancy was significantly higher than in normal pregnancy and significant correlation was observed between mean blood pressure and its activity. Higher activity in the umbilical vein than in the umbilical artery indicated production of the factor in the placenta.
Prostaglandin(PG) <I_2> has the lowering effect on blood pressure by relaxation of the blood vessels. Impaired activity.of PG <I_2> production in the endothelium of the blood vessels, therefore, may increase sensitivity of the vessels to pressor substances. Our experimental results showed that production of PG <I_2> was activated in mild toxemia more than in normal pregnancy, whereas in severe one its production was restricted to great extent so that toxemia may be aggravated.
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Report
(1 results)
Research Products
(8 results)
