The Experts below are selected from a list of 96 Experts worldwide ranked by ideXlab platform

Isabelle Woditsch - One of the best experts on this subject based on the ideXlab platform.

  • On-line measurement of nitric oxide release from Organic nitrates in the intact coronary Circulation
    Naunyn-Schmiedeberg's Archives of Pharmacology, 1991
    Co-Authors: Karsten Schrör, Stefan Förster, Isabelle Woditsch
    Abstract:

    This study determines the release of nitric oxide (NO) from the coronary Circulation of Langendorff hearts of rabbits, subsequent to administration of glyceryl trinitrate (GTN) and SIN-1. NO was measured on-line in the coronary effluent by the oxyhaemoglobin technique. Infusion of either GTN (10–40 moles/l) or SIN-1 (0.1–2.3 μmoles/l) into the coronary inflow resulted in a concentration-dependent NO release into the coronary effluent and a decrease in the coronary vascular resistance. NO generation from SIN-1 was identical with and without passage of the coronary Circulation whereas NO generation from GTN was only detected after passage of the coronary vascular bed. NO generation by both substances was in the same range as endogenous NO release by two endothelium-dependent vasodilators, bradykinin (0.05 μmoles/l) and substance P (0.05 μmoles/l). Oxyhaemoglobin used for the assay of NO, inhibited the relaxation by SIN-1, but did not reduce vessel relaxations induced by GTN or iloprost, a stable prostacyclin analogue. Removal of the coronary endothelium by trypsin or pretreatment with L-N^G-Monomethyl-arginine (30 μmoles/l) did neither affect NO release from GTN and SIN-1 nor the vasodilatory effect of both substances. These data are the first to directly demonstrate endothelium-independent NO release from Organic nitrates during passage of an intact Organ Circulation. They additionally suggest a subendothelial site of metabolic NO formation from GTN.

  • Reduced nitric oxide release causes nitrate tolerance in the intact coronary Circulation
    Journal of Cardiovascular Pharmacology, 1991
    Co-Authors: Stefan Förster, Isabelle Woditsch, Henning Schröder, Karsten Schrör
    Abstract:

    We investigated the possible involvement of reduced nitric oxide (NO) formation in development of nitrate tolerance in an intact Organ Circulation. NO formation was measured spectrophotometrically on-line in the coronary effluent of Langendorff hearts of rabbits. Short-term (3 min) infusion of glyceryl nitrate (GTN, 40 μM) or a sydnonimine, into the coronary vascular resistance and NO release into the coronary effluent. Pretreatment with 250 μM GTN for 30 min resulted in considerably reduced NO formation and coronary vasodilation, whereas NO release and coronary vasolidation subsequent to SIN-1 remained unchanged

Karsten Schrör - One of the best experts on this subject based on the ideXlab platform.

  • On-line measurement of nitric oxide release from Organic nitrates in the intact coronary Circulation
    Naunyn-Schmiedeberg's Archives of Pharmacology, 1991
    Co-Authors: Karsten Schrör, Stefan Förster, Isabelle Woditsch
    Abstract:

    This study determines the release of nitric oxide (NO) from the coronary Circulation of Langendorff hearts of rabbits, subsequent to administration of glyceryl trinitrate (GTN) and SIN-1. NO was measured on-line in the coronary effluent by the oxyhaemoglobin technique. Infusion of either GTN (10–40 moles/l) or SIN-1 (0.1–2.3 μmoles/l) into the coronary inflow resulted in a concentration-dependent NO release into the coronary effluent and a decrease in the coronary vascular resistance. NO generation from SIN-1 was identical with and without passage of the coronary Circulation whereas NO generation from GTN was only detected after passage of the coronary vascular bed. NO generation by both substances was in the same range as endogenous NO release by two endothelium-dependent vasodilators, bradykinin (0.05 μmoles/l) and substance P (0.05 μmoles/l). Oxyhaemoglobin used for the assay of NO, inhibited the relaxation by SIN-1, but did not reduce vessel relaxations induced by GTN or iloprost, a stable prostacyclin analogue. Removal of the coronary endothelium by trypsin or pretreatment with L-N^G-Monomethyl-arginine (30 μmoles/l) did neither affect NO release from GTN and SIN-1 nor the vasodilatory effect of both substances. These data are the first to directly demonstrate endothelium-independent NO release from Organic nitrates during passage of an intact Organ Circulation. They additionally suggest a subendothelial site of metabolic NO formation from GTN.

  • Reduced nitric oxide release causes nitrate tolerance in the intact coronary Circulation
    Journal of Cardiovascular Pharmacology, 1991
    Co-Authors: Stefan Förster, Isabelle Woditsch, Henning Schröder, Karsten Schrör
    Abstract:

    We investigated the possible involvement of reduced nitric oxide (NO) formation in development of nitrate tolerance in an intact Organ Circulation. NO formation was measured spectrophotometrically on-line in the coronary effluent of Langendorff hearts of rabbits. Short-term (3 min) infusion of glyceryl nitrate (GTN, 40 μM) or a sydnonimine, into the coronary vascular resistance and NO release into the coronary effluent. Pretreatment with 250 μM GTN for 30 min resulted in considerably reduced NO formation and coronary vasodilation, whereas NO release and coronary vasolidation subsequent to SIN-1 remained unchanged

Stefan Förster - One of the best experts on this subject based on the ideXlab platform.

  • On-line measurement of nitric oxide release from Organic nitrates in the intact coronary Circulation
    Naunyn-Schmiedeberg's Archives of Pharmacology, 1991
    Co-Authors: Karsten Schrör, Stefan Förster, Isabelle Woditsch
    Abstract:

    This study determines the release of nitric oxide (NO) from the coronary Circulation of Langendorff hearts of rabbits, subsequent to administration of glyceryl trinitrate (GTN) and SIN-1. NO was measured on-line in the coronary effluent by the oxyhaemoglobin technique. Infusion of either GTN (10–40 moles/l) or SIN-1 (0.1–2.3 μmoles/l) into the coronary inflow resulted in a concentration-dependent NO release into the coronary effluent and a decrease in the coronary vascular resistance. NO generation from SIN-1 was identical with and without passage of the coronary Circulation whereas NO generation from GTN was only detected after passage of the coronary vascular bed. NO generation by both substances was in the same range as endogenous NO release by two endothelium-dependent vasodilators, bradykinin (0.05 μmoles/l) and substance P (0.05 μmoles/l). Oxyhaemoglobin used for the assay of NO, inhibited the relaxation by SIN-1, but did not reduce vessel relaxations induced by GTN or iloprost, a stable prostacyclin analogue. Removal of the coronary endothelium by trypsin or pretreatment with L-N^G-Monomethyl-arginine (30 μmoles/l) did neither affect NO release from GTN and SIN-1 nor the vasodilatory effect of both substances. These data are the first to directly demonstrate endothelium-independent NO release from Organic nitrates during passage of an intact Organ Circulation. They additionally suggest a subendothelial site of metabolic NO formation from GTN.

  • Reduced nitric oxide release causes nitrate tolerance in the intact coronary Circulation
    Journal of Cardiovascular Pharmacology, 1991
    Co-Authors: Stefan Förster, Isabelle Woditsch, Henning Schröder, Karsten Schrör
    Abstract:

    We investigated the possible involvement of reduced nitric oxide (NO) formation in development of nitrate tolerance in an intact Organ Circulation. NO formation was measured spectrophotometrically on-line in the coronary effluent of Langendorff hearts of rabbits. Short-term (3 min) infusion of glyceryl nitrate (GTN, 40 μM) or a sydnonimine, into the coronary vascular resistance and NO release into the coronary effluent. Pretreatment with 250 μM GTN for 30 min resulted in considerably reduced NO formation and coronary vasodilation, whereas NO release and coronary vasolidation subsequent to SIN-1 remained unchanged

H Matsuki - One of the best experts on this subject based on the ideXlab platform.

  • development of an implantable undulation type ventricular assist device for control of Organ Circulation
    Artificial Organs, 2004
    Co-Authors: Tomoyuki Yambe, Kou Imachi, Yasuyuki Shiraishi, Mune Ichi Shibata, Tasuku Yamaguchi, Q Wang, Xudong Duan, Makoto Yoshizawa, Akira Tanaka, H Matsuki
    Abstract:

    : It is well known that a rotary blood pump (RP) is effective as a small ventricular assist device (VAD). It might be still more effective if pulsation was available. The undulation pump (UP), which is a type of small RP, can also produce pulsation. In Japan, a development project for an implantable type UP ventricular assist device (UPVAD) is now advanced. Six universities and some companies together have been in charge of the development project for 5 years. In this study, the influence which the UP under development has on Circulation in internal Organs was investigated. Goats with the same weight as an average Asian person were used for the experiment. The left chest cavity was opened after resection of the fourth rib and the heart was approached. A cannula was inserted in the left ventricle from the apex. An outflow cannula was inserted into the left descending aorta. Heart muscle was excised using a newly developed puncher. The UPVAD was implanted using a left-heart bypass system. The myocardial blood flow, carotid arterial blood flow, and the kidney blood flow were recorded together with an electrocardiogram, blood pressure, and the flow rate. In these animal experiments, the blood Circulation dynamic state was stabilized and sufficient support of the left heart was observed. Myocardial blood flow, carotid arterial flow, and a kidney blood flow increase resulting from UPVAD support was observed. Often the problem of multiple Organ failure is important at the time of clinical application of a ventricular assist device. Assisting Circulation to internal Organs is important for prevention of multiple Organ failure. It was concluded that the UPVAD might be useful for prevention of multiple Organ failure.

Shoichi Imai - One of the best experts on this subject based on the ideXlab platform.

  • Effects of sodium nitroprusside (MR7S1) and nitroglycerin on the systemic, renal, cerebral, and coronary Circulation of dogs anesthetized with enflurane
    Cardiovascular Drugs and Therapy, 1992
    Co-Authors: Masami Hamaguchi, Takaharu Ishibashi, Naoki Katsumata, Akio Mitomi, Shoichi Imai
    Abstract:

    In beagle dogs anesthetized with enfluranenitrous oxide, effects of sodium nitroprusside (SNP; MR7S1) and nitroglycerin (NTG) on hemodynamics and main Organ Circulation were studied to evaluate their effectiveness and safety as hypotensive agents during anesthesia. SNP (MR7S1) infusion (1–10 μg/kg/min) decreased arterial blood pressure in a dose-dependent manner. The hypotension was stable during the infusion. After discontinuation of infusion, the blood pressure rapidly returned to the initial level. The hypotension was associated with decreases in cardiac output and total peripheral resistance. NTG infusion (3–10 μg/kg/min) decreased arterial blood pressure, too, but the hypotension was less marked and not dose dependent, and the recovery was slower. Neither drug changed the heart rate. Infusion of SNP (MR7S1) and NTG did not change the hypotension induced by the injection of adenosine, SNP, and NTG. Furthermore, cerebral blood flow, cerebral oxygen consumption, and renal blood flow were unchanged during the hypotension produced by either drug. Coronary blood flow was decreased, but this was due to decreases in cardiac oxygen consumption. In conclusion, SNP (MR7S1) is superior to NTG as a hypotensive agent during anesthesia in efficacy, clear dose dependency, and rapid recovery. The hypotension induced by NTG as well as SNP (MR7S1) seems to have no undesirable effects on the Circulation of important Organs.