| Co-Investigator(Kenkyū-buntansha) |
NISHIDA Yasuhiro KAGAWA MEDICAL SCHOOL, PHYSIOLOGY, ASSISTANT, 医学部, 助手 (90172668)
ISHIDA Toshihiko KAGAWA MEDICAL SCHOOL, INTERNAL MEDICINE, ASSOCIATE, 医学部附属病院, 講師 (50159737)
MORITA Hironobu KAGAWA MEDICAL SCHOOL, PHYSIOLOGY, ASSOCIATE, 医学部, 講師 (80145044)
TANAKA Satoshi KAGAWA MEDICAL SCHOOL, SURGERY, PROFESSOR, 医学部, 教授 (30033062)
MATSUO Hisayuki MIYAZAKI MEDICAL COLLEGE, BIOCHEMISTRY, PROFESSOR, 医学部, 教授 (50028685)
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| Research Abstract |
We have studied following subjects; A) effect of atrial natriuretic peptide (ANP) on pulmonary circulation, B) uptake of ANP by the visceral organs, C) effect of ANP on visceral circulation, D) effect of ANP on water and NaCl absorption across the intestine, E) effects of ANP on coronary circulation, myocardial oxygen consumption and cardiac function, F) effect of ANP on glucose metabolism.
A) PULMONARY CIRCULATION ANP attenuated an increase in incremental pulmonary vascular resistance of vascularly isolated and ventilated lung lobe caused by elevation of pulmonary venous pressure. Control incremental pulmonary vascular resistance was not affected by ANP. Intravenous infusion of ANP decreased arterial oxygen partial pressure.
B) UPTAKE OF ANP BY THE VISCERAL ORGANS The intestine took about 25% of delivered ANP, but the liver did not.
C) VISCERAL CIRCULATION ANP decreased hepatic arterial blood flow (HAF) and portal venous flow (PVF) as well as cardiac output (CO). Decreases of HAF and PVF were about the same ratio as CO. This means that ANP does not affect visceral circulation.
D) WATER AND NaCl ABSORPTION ACROSS THE INTESTINE ANP suppressed water and NaCl absorption across the jejunum but not across the ileum.
E) CORONARY CIRCULATION, MYOCARDIAL OXYGEN CONSUMPTION AND CARDIAC FUNCTION Intravenous infusion of ANP decreased arterial pressure, left atrial pressure, left ventricular pressure, cardiac output, coronary blood flow, dP/dt and myocardial oxygen consumption, and increases heart rate. When left atrial pressure was maintained at the control level, ANP did not cause these changes. Therefore, these changes are secondary to a decrease of circulating blood volume caused by ANP. A decrease of circulating blood volume caused by infusion of ANP (0.3 micro-gram/kg for 30min) was 18.2 ml. ANP decreases circulating blood volume but does not affect cardiac function.
F) GLUCOSE METABOLISM This is on-going project.
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