People complain about nasal stuffiness after SO2 exposure. This study was to investigate the acute effects of SO2 on nasal vascular and airway resistances in anaesthetized pigs for elucidating the underlying vascular and control mechanisms. Controlled ventilation was passed to the lungs or retrogradely through each nasal cavity. Nasal airway and lower airway pressures were measured to reflect airflow resistance changes. Systemic arterial pressure and nasal arterial flow were measured to calculate nasal vascular resistance. Nasal and pulmonary SO2 challenges were given. At 2 ppm, SO2 decreased systemic blood pressure and nasal vascular resistance but increased nasal airway and lower airway resistances. With increasing level to 8 ppm, SO2 increased systemic arterial pressure, nasal vascular and lower airway resistances but decreased nasal airway resistance. Nasal and pulmonary challenges induced similar responses. Ipsilateral nasal challenge elicited bilateral responses. Ruthenium red abolished the responses to nasal challenges. Bilateral vagosympathectomy eliminated the responses to lung challenges. Hence, SO2 at 2 ppm causes nasal congestion through sensory reflex vasodilatation but at higher levels nasal decongestion through sensory reflex vasoconstriction. Nasal congestion coupled with bronchoconstriction at levels of SO2 below short-term exposure limit (STEL) (≤ 2 ppm) would limit SO2 entering the lungs. Nasal decongestion at levels of SO2 beyond STEL (> 2 ppm) can effectively decrease total airway resistance as concurrent strong bronchoconstriction may impair ventilation.
Administration, Inhalation ; Airway Resistance ; drug effects ; Animals ; Lung ; drug effects ; Nasal Cavity ; drug effects ; Respiration ; Sulfur Dioxide ; pharmacology ; Swine ; Vascular Resistance ; drug effects ; Vasodilation

No abstract available.
Cholecalciferol/*administration & dosage ; Diabetes Mellitus, Type 2/*drug therapy ; Female ; Humans ; *Insulin Resistance ; Male ; Vascular Stiffness/*drug effects

OBJECTIVETo observe the effect of polyethylene oxide (PEO) solution at different concentrations on abdominal aortic blood flow and vascular resistance in rats and evaluate the safety and drag-reducing effect of PEO solution.

METHODSThirty-two rats were anesthetized and randomly divided into 4 groups. An ultrasonic flow probe was deployed on the abdominal aorta (5 mm above the common iliac artery) to measure the blood flow. The carotid artery pressure, iliac artery pressure, iliac vein pressure, central venous pressure (CVP) and ECG were also monitored. Saline or different concentrations of PEO [(1x10(-6)(low), 1x10(-5)(middle) and 5x10(-5)(high) g/ml)] were injected in the 4 groups of rats through the caudal vein at a constant rate of 5 ml/h for 20 min, and the changes of the vascular resistance was observed. RESULTS After injections of 1x10(-6) and 1x10(-5) g/ml PEO, the abdominal aortic flow increased significantly (P<0.05) while the vascular resistance was reduced (P(low)=0.052, P(middle)<0.001) as compared to those in the saline control group. Following the injection with 5x10(-5) g/ml PEO, the abdominal aortic flow increased to a threshold in the initial 4 min, after which it rapidly decreased to approach the baseline levels despite continuous infusion. Blood pressure remained stable after the injections except for 5x10(-5) g/mlPEO injection, which resulted in a reduction of the blood pressure by about 10 mmHg (P=0.014). The heart rate and CVP both underwent no significant changes following the injections.

CONCLUSIONThe drag-reducing effect of PEO is closely related to its concentration, and compared with 1x10(-6) g/ml, 1x10(-5) g/ml PEO more effectively increases the blood flow and decreases the resistance. The effectiveness and safety of EPO are attenuated at a concentration higher than 5x10(-5) g/ml.

Animals ; Aorta, Abdominal ; physiology ; Blood Flow Velocity ; drug effects ; Dose-Response Relationship, Drug ; Male ; Polyethylene Glycols ; pharmacology ; Random Allocation ; Rats ; Rats, Wistar ; Vascular Resistance ; drug effects

Transcranial Doppler (TCD) was carried out to determine the resistive index (RI) values of normal canine cerebral arteries and its reproducibility and to evaluate the change of cerebral vascular resistance following diuretics administration. RI values of rostral cerebral artery (RCA) were compared between fontanelle window and temporal window. Normal ranges and reproducibility of the RI values were examined in the rostal cerebral artery (RCA) and caudal cerebral artery (CCA). And after administration of diuretics, TCD-derived RI values were measured at RCA and CCA. Cerebral vascular RI values of RCA and CCA were 0.55 +/- 0.05 and 0.55 +/- 0.03 in the normal dogs, respectively. There was no significant difference of RI between male and female; between fontanelle window and temporal window. Reproducibility of RI measurements between intraobserver and interobserver were relatively high. The RI of RCA and CCA were significantly increased 15 minutes after mannitol administration (p<0.01) and returned to baseline values by 30 minutes, but it did not significantly change after furosemide and saline administration. The results suggest that TCD is a useful test which can obtain reproducible results from any window and has the advantage of detecting subtle changes in cerebral vascular resistance.
Animals ; Cerebral Arteries/drug effects/*ultrasonography ; Diuretics/pharmacology ; Dogs/*physiology ; Feasibility Studies ; Furosemide/pharmacology ; Mannitol/pharmacology ; Reference Values ; Reproducibility of Results ; Ultrasonography, Doppler/*veterinary ; Vascular Resistance/drug effects/*physiology

BACKGROUNDUnder an insulin resistance (IR) state, overproduction of reactive oxygen species (ROS) may be playing a major role in the pathogenesis of endothelial dysfunction, hypertension and atherosclerosis. Recently, increasing attention has been drawn to the beneficial effects of heme oxygenase-1 (HO-1) in the cardiovascular system. This study aimed to investigate the effects of HO-1 on vascular function of thoracic aorta in IR rats and demonstrate the probable mechanisms of HO-1 against endothelial dysfunction in IR states.

METHODSSprague-Dawley (SD) rats fed with high-fat diet for 6 weeks and the IR models were validated with hyperinsulinemic-euglycemic clamp test. Then the IR rat models (n = 44) were further randomized into 3 subgroups, namely, the IR control group (n = 26, in which 12 were sacrificed immediately and evaluated for all study measures), a hemin treated IR group (n = 10) and a zinc protoporphyrin-IX (ZnPP-IX) treated IR group (n = 8) that were fed with a high-fat diet. Rats with standardized chow diet were used as the normal control group (n = 12). The rats in IR control group, hemin treated IR group and ZnPP-IX treated IR group were subsequently treated every other day with an intraperitoneal injection of normal saline, hemin (inducer of HO-1, 30 micromol/kg) or ZnPP-IX (inhibitor of HO-1, 10 micromol/kg) for 4 weeks. Rats in the normal control group remained on a standardized chow diet and were treated with intraperitoneal injections of normal saline every other day for 4 weeks. Systolic arterial blood pressure (SABP) was measured by tail-cuffed microphotoelectric plethysmography. The blood carbon monoxide (CO) was measured by blood gas analysis. The levels of nitric oxide (NO), inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), blood glucose (BG), insulin, total cholesterol (TC) and triglyceride (TG) in serum, and the levels of total antioxidant capacity (TAOC), malondialdehyde (MDA) and superoxide dismutase (SOD) in the aorta were measured. The expression of HO-1 mRNA and HO-1 protein in aortal tissue were detected by semi-quantitative RT-PCR and Western blot. The vasoreactive tensometry was performed with thoracic aortic rings (TARs).

RESULTSCompared with the normal control group, the levels of SABP, BG, insulin, TC, TG, NO, iNOS and MDA were higher, while the levels of CO, TAOC, SOD and eNOS were lower in IR control rats. After treatment of IR rats for 4 weeks a more intensive expression of HO-1 mRNA and HO-1 protein were observed in hemin treated IR group compared with the normal control group. And compared with 4-week IR control rats, the levels of CO, TAOC, SOD and eNOS were increased, while the levels of SABP and iNOS activity were lower in the hemin treated IR group. Administration of hemin in IR rats appeared to improve the disordered vasorelaxation of TARs to acetylcholine (ACh). Alternatively, the reverse results of SABP, CO, TAOC, SOD, iNOS and vasorelaxation responses to ACh were observed in IR rats with administration of ZnPP-IX.

CONCLUSIONSThe endothelial dysfunction in the aorta is present in the IR state. The protective effects of HO-1 against aortic endothelial dysfunction may be due to its antioxidation and regulative effect of vasoactive substances. It is proposed that hemin, inducer of HO-1, could be a potential therapeutic option for vascular dysfunction in IR states.

Animals ; Aorta ; drug effects ; physiology ; Carbon Monoxide ; blood ; Endothelium, Vascular ; drug effects ; physiology ; Enzyme Induction ; drug effects ; Heme Oxygenase-1 ; analysis ; biosynthesis ; genetics ; Hemin ; pharmacology ; Insulin Resistance ; Male ; Nitric Oxide ; blood ; Oxidative Stress ; Rats ; Rats, Sprague-Dawley ; Systole ; drug effects

OBJECTIVETo study the effects of Naoan tablets on brain hemodynamics and cerebral microcirculation of soft membrane.

METHODCerebral blood stream flux, resistance of blood vessels, blood pressure and heart rate were used as observation indexes in hemodynamics experiment. Artery caliber and the number of capillaries with recovered blood stream were used as observation indexes in microcirculation experiment.

RESULTNaoan tablets at dose of 0.5 g x kg(-1) and 1.0 g x kg(-1) could enhance cerebral blood stream flux, decrease resistance of blood vessels, and reduce blood pressure. While no effects on heart rate. Naoan tablet at dose of 0.7 g x kg(-1) and 2.1 g x kg(-1) could increase the number of capillaries with recovered blood stream and enlarge the artery caliber of soft membrane in rats.

CONCLUSIONNaoan tablets can improve the indexes of hemodynamics and cerebral microcirculation of soft membrane.

Anesthesia ; Animals ; Brain ; blood supply ; Cerebrovascular Circulation ; drug effects ; Codonopsis ; chemistry ; Dogs ; Drug Combinations ; Drugs, Chinese Herbal ; pharmacology ; Female ; Ligusticum ; chemistry ; Male ; Microcirculation ; drug effects ; Plants, Medicinal ; chemistry ; Random Allocation ; Rats ; Rats, Wistar ; Tablets ; Vascular Resistance ; drug effects

Persistent pulmonary hypertension of the newborn infant (PPHN), is a clinical syndrome characterized by elevated pulmonary vascular resistance, resulting from reactive vasoconstriction or structural remodeling of the pulmonary vasculature. Although inhaled nitric oxide (iNO) has emerged as a novel selective treatment of PPHN, responses to iNO are variable according to the etiologies or the clinical situation. A retrospective chart review of 51 newborn infants with PPHN and treated with iNO, was undertaken to evaluate the factors affecting response to iNO. Response to iNO was defined as a reduction in the oxygenation index (OI) of more than 20%, or disappearance of the difference in oxygen saturation between preductal and postductal circulation after iNO therapy. The patients were divided into two groups; the responder group and the non- responder group. Respiratory distress syndrome (RDS) was more commonly associated with PPHN in the responder group than in the non-responder group (p < 0.05), while there were many more patients with congenital diaphragmatic hernia (CDH) in the non-responder group than in the responder group (p < 0.05). Infants with meconium aspiration syndrome (MAS) were similar in both of the two groups. Initial OI, initial mean airway pressure (MAP), and initial and peak NO concentration were significantly lower in the responder group compared to the non-responder group (p < 0.05). Rapid response (response to iNO within the first hour) was shown in 74% of the responder group and 33% of the nonresponder group (p < 0.05). There was no significant differences in the initial chest radiographic findings, such as normal, focal or bilateral diffuse infiltration, with the exception of CDH, between each group. Lower initial OI, lower initial MAP and significant response within the first hour were shown to be favourable factors in response to iNO therapy. Patients with RDS associated with PPHN responded much better to iNO than those with other diseases.
Administration, Inhalation ; Female ; Human ; Infant, Newborn ; Male ; Nitric Oxide/*administration & dosage ; Persistent Fetal Circulation Syndrome/*drug therapy/radiography ; Retrospective Studies ; Treatment Outcome ; Vascular Resistance/drug effects

BACKGROUNDThe hyperdynamic circulatory state in end-stage liver disease is similar to the hemodynamic state in endotoxic shock. Recent research indicated that proper use of norepinephrine (NE) in patients with endotoxic shock could improve the perfusion of visceral organs and raise the survival rate. In this study, dopamine (DA) or NE combined with DA was infused during the orthotopic liver transplantation (OLT) to observe and compare their effects on hemodynamics, oxygenation, and renal function during different stages of the operation.

METHODSThirty American Society of Anesthesiology (ASA) III-IV patients undergoing OLT were randomly divided into group DA and group NE with 15 patients in each group. Vasopressors were infused after induction of anesthesia. DA was infused in group DA; DA and NE in group NE. Data of hemodynamics, oxygenation and renal function were collected after induction, 1 hour in preanhepatic, anhepatic, neohepatic phase and at the end of operation.

RESULTSHeart rate (HR) and mean arterial pressure (MAP) of the two groups were stable. In anhepatic phase, central venous pressure (CVP), mean pulmonary arterial pressure (MPAP), pulmonary arterial wedge pressure (PAWP), cardiac output (CO), and cardiac index (CI) decreased, whereas systemic vascular resistance (SVR) and systemic vascular resistance index (SVRI) increased significantly (P < 0.05). The hemodynamic variables of group NE were more stable than that of group DA. Pulmonary vascular resistance (PVR), pulmonary vascular resistance index (PVRI), power of hydrogen (pH), and mixed venous oxygen saturation (SvO2) had no significant changes. Oxygen delivery (DO2) and oxygen consumption (VO2) decreased during anhepatic phase (P < 0.05), but lactic acid (LAC) increased since anhepatic phase. Blood urea nitrogen (BUN) maintained relatively stable during different phases. Group NE had more urine output (F = 4.733, P = 0.039).

CONCLUSIONSDuring OLT, both DA and NE combined with DA can maintain hemodynamics stable, whereas the latter may create better condition. NE has positive effects on maintenance of renal function.

Adult ; Blood Pressure ; drug effects ; Blood Urea Nitrogen ; Dopamine ; pharmacology ; Female ; Heart Rate ; drug effects ; Humans ; Hydrogen-Ion Concentration ; Liver Transplantation ; Male ; Middle Aged ; Norepinephrine ; pharmacology ; Vascular Resistance ; drug effects

OBJECTIVETo observe the effects of series of Muskone (the muskone includes Slender Dutchmanspipe Root, Inula Root and neither kind of Common Aucklandia Root) on the heart hemodynamics and myocardial consumption of oxygen in experimental dogs, and to explain its pharmacological action on cardiovascular system.

METHODArterial blood pressure, coronary blood flow, resistance in coronary artery, total peripheral resistance, work of left artrium and oxygen consumption index of the cardiac muscles were observed in anaesthetic dogs.

RESULTThe series of Muskone decreased arterial blood pressure significantly, dilated coronary artery and peripheral arteries significantly, increased coronary blood flow, decreased resistance in coronary artery, improved the work of left artrium, the oxygen availability of cardiac muscles and the complaisance of arteries in cardiac muscles.

Animals ; Aristolochia ; chemistry ; Asteraceae ; chemistry ; Blood Pressure ; drug effects ; Coronary Circulation ; drug effects ; Cycloparaffins ; isolation & purification ; pharmacology ; Dogs ; Drug Combinations ; Female ; Heart ; drug effects ; physiology ; Hemodynamics ; drug effects ; Inula ; chemistry ; Male ; Myocardium ; metabolism ; Oxygen Consumption ; drug effects ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry ; Vascular Resistance ; drug effects

AIMTo observe the effect of phenolic alkaloids of Menispermum dauricum (PAMD) on the hemodynamics, coronary circulation and oxygen metabolism of the myocardium in anesthetized dogs.

METHODSIn this study, the changes of LVSP, LVEDP and +/- dp/dtmax, the flow of coronary artery and myocardial energy metabolism were measured in anesthetized dog with PAMD or NS.

RESULTSIn the anesthetized dogs, compared with pre-treatment status, PAMD at 3.5 and 7.0 mg.kg-1 caused decreases in the left ventricular systolic pressure(LVSP), +/- dp/dtmax, heart rate, the rate of oxygen utilization, the coronary and general peripheral resistance. It was found to increase myocardial oxygen and coronary flow. There were no significant change in the left ventricular end diastolic pressure (LVEDP).

CONCLUSIONPAMD can ameliorate hemodynamics, coronary circulation and myocardial metabolism.

Alkaloids ; isolation & purification ; pharmacology ; Animals ; Blood Pressure ; drug effects ; Cardiac Output ; drug effects ; Coronary Circulation ; drug effects ; Dogs ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Female ; Heart Rate ; drug effects ; Male ; Menispermum ; chemistry ; Oxygen Consumption ; drug effects ; Plants, Medicinal ; chemistry ; Random Allocation ; Vascular Resistance ; drug effects