共查询到20条相似文献,搜索用时 31 毫秒
1.
P.M.Shaughn O'Brien G.Marcus Filshie Fiona Broughton Pipkin 《Prostaglandins & other lipid mediators》1977,13(1):171-181
The rise in arterial blood pressure in response to angiotensin II was studied in the last third of pregnancy in rabbits. The response was compared with that of pregnant rabbits during infusion of prostaglandin E2 and F2α. Prostaglandin E2 significantly diminished the rise in diastolic pressure in response to angiotensin II. Prostaglandin F2α did not alter the response. Intravenous indomethacin elevated the blood pressure and caused an absolute increase in the pressor response. It did not mediate a change in the percentage rise in blood pressure in response to angiotensin II. 相似文献
2.
Dopamine and prostaglandin A1 were infused intravenously in 4 patients with the hepatorenal syndrome, in 1 patient with acute tubular necrosis, and 1 patient with cortical necrosis. Large doses of prostaglandin A1 decreased arterial blood pressure preventing increase in dosage; in contrast, high doses of dopamine elevated blood pressure. When the two drugs were administered conjointly, much larger doses of each agent could be administered without change in arterial blood pressure. Significant improvement of renal function was not observed in any of these critically ill patients during or within 24 hours after dopamine and prostaglandin A1 administration. This study demonstrated that extremely large doses of these vasodilating agents can be safely administered conjointly. 相似文献
3.
Nancy J. Kenney 《Prostaglandins & other lipid mediators》1983,25(3):335-342
Repeated intracerebroventicular injections of 1 μg prostacyclin reduce mean arterial pressure of conscious normotensive rats and reverse the elevation of blood pressure of conscious rats resulting from the intraventricular injection of angiotensin II. The reduction of blood pressure of normotensive rats by prostacyclin is enhanced by pretreatment with probenecid, an inhibitor of fatty-acid transport across biological membranes. Although probenecid does not completely inhibit the transport of fatty acids from the brain to the periphery, the greater effectiveness of prostacyclin in probenecid-treated animals suggests that centrally injected prostacyclin need not leak into the periphery to reduce blood pressure. When the dose of prostacyclin is reduced to 100 ng repeated each minute for 10 min, no change of blood pressure of normotensive rats is observed. The failure of the lower dose of prostacyclin to reduce blood pressure may be due to its rapid degradation. Ventricular injections of 6-keto-prostaglandin F1a, a major product of prostacyclin metaolism, causes an increase of blood pressure which may counteract the action of prostacyclin itself. 相似文献
4.
L.G. Letts D.L. Newman S.E. Greenwald Priscilla J. Piper 《Prostaglandins & other lipid mediators》1983,26(4):563-572
The left anterior descending coronary artery in anaesthetized greyhounds was perfused at constant pressure with blood pumped from the carotid artery. Phasic and mean coronary flow, left ventricular pressure, dP/dt, cardiac output, ECG, heart rate and systemic pressure were measured. Leukotriene (LT) D4 was administered into the left anterior descending coronary artery as a bolus injection. LTD4 caused dose-related reductions in coronary flow. Other parameters showed little immediate change although a gradual decrease in left ventricular pressure, dP/dt, cardiac output and systemic pressure occurred after administration of LTD4. Following intracoronary administration of LTD4 small surface haemorrhages were observed over the area perfused. The reduction in coronary flow was not inhibited by indomethacin. 相似文献
5.
Kiyoshi Oshima Kimiichiro Matsumoto Takeshi Tsuda Kuniharu Shibata Motoharu Hayashi 《Prostaglandins & other lipid mediators》1978,15(3):473-483
The smooth muscle stimulating activity of a new PGE1 analog, 16, 16-dimethyl-trans-Δ2-PGE1 methyl ester (ONO-802) was evaluated by simulataneous;y recording the EMG of the uterus and intestines, along with urinary bladder pressure, and blood pressure in pregnant and non-pregnant Japanese monkeys (). Single intravenous injections of ONO-802 in increasing dosages (0.2–5 μg/kg) were found to be 50–100 times or more effective in inducing uterine contraction than PGF2α and PGE1. A mild, transient gastrointestinal muscle stimulating activity was observed, but change in urinary bladder pressure and blood pressure was not evident. ONO-802 induced uterine contractions in the pregnant animals were 10 times greater than in the non-pregnant animals. These results suggest that ONO-802 may be a suitable clinical prostaglandin for use in therapeutic abortion. 相似文献
6.
The following experiments were designed in order to examine the inter-relationships of various prostaglandins (PG's) and the adrenergic nervous system, in conjunction with blood pressure and heart rate responses, . Stimulation of the entire spinal cord (50v, 0.3–3 Hz, 1.0 msec) of the pithed rat increased blood pressure, heart rate and plasma epinephrine (EPI) and norepinephrine (NE) concentration (radioenzymatic-thin layer chromatographic assay). Infusion of PGE2(10–30 μg/kg. min, i.v.) suppressed blood pressure and heart rate responses to spinal cord stimulation while plasma EPI (but not NE) was augmented over levels found in control animals. PGI2 (0.03–3.0 μg/kg. min, i.v.) suppressed the blood pressure response to spinal cord stimulation without any effect on heart rate or the plasma catecholamine levels. PGE2 and PGF2α(10–30 μg/kg. min, i.v.) did not change the blood pressure, heart rate or plasma EPI and NE responses to the spinal cord stimulation although PGF2α disclosed an overall vasopressor effect during the pre-stimulation period. At the pre-stimulation period it was also observed that PGE2, PGF2α and PGI2, had a positive chronotropic effect on the heart rate, the cardiac accelerating effect of PGE2 was not abolished by propanolol. These studies suggest that in the rat, PGE2 and PGI2 modulate sympathetic responses, primarily by interaction with the post-synaptic elements — PGE2 on both blood vessels and the heart and PGI2 by acting principally on blood vessels. 相似文献
7.
Central neurotransmitter receptors in hypertensive rats 总被引:1,自引:0,他引:1
Muscarinic cholinergic ([3H]QNB), α1 ? ([3H]WB-4101), and α2 ? ([3H]clonidine) adrenergic ligand binding was measured in various regions of the brains of adult normotensive, spontaneously hypertensive, and DOCA-salt hypertensive rats. There was a 66% increase in the number of α1-adrenergic receptors in hypothalamus of the spontaneously hypertensive rats as compared to normotensive controls, with no change in the Kd value. There were no other differences in the spontaneously hypertensive rats and none in the DOCA-salt model. α1-Adrenergic binding was elevated in hypothalamus of spontaneously hypertensive rats 4–20 weeks of age even though blood pressure in the 4-week old animals was not at hypertensive levels (i.e., <150 mmHg). Treatment of adult spontaneously hypertensive rats with clonidine HCl significantly reduced blood pressure but failed to alter the binding of [3H]WB-4101 in hypothalamus. Thus, it appears that the enhanced number of α1-adrenergic receptors in hypothalamus of spontaneously hypertensive rats is neither a consequence of the increased blood pressure, nor a phenomenon common to all models of hypertension. 相似文献
8.
P. R. Terrio D. F. Stiffler 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1994,164(4):272-277
Larval Ambystoma tigrinum were examined to determine their cardiovascular responses to three types of acidosis: metabolic acidosis via NH4Cl gavage; respiratory acidosis via hypercapnia; and anesthetic-induced acidosis, via triacine methanesulphonate. In addition, another group of (metabolic acidosis) animals were tested to determine the role of -mediated catecholamine control on cardiovascular and acid-base regulation. The metabolic and respiratory acidoses produced typical amphibian responses. Anesthesia produced a significant mixed acidosis with respiratory and metabolic components. The cardiovascular responses to metabolic and respiratory acidosis were increased heart rate and pulse pressure. There were no significant changes in diastolic pressure, however, systolic pressure increased as a result of the increased pulse pressure. Animals subjected to metabolic acidosis via -blockade with propranolol did not display the increased heart rate and pulse pressure and the acidosis was deepened and prolonged. Anesthesia resulted in a cardiac slowing and increased pulse pressure, probably explained by the Frank-Starling relationship. There was no change in diastolic pressure. Anesthetized animals had depressed blood O2 tension and elevated blood lactate.Abbreviations HR
heart rate
- RBC
red blood cell(s)
- TMS
triacine methanesulphonate 相似文献
9.
Projections of climate‐driven changes in tuna vertical habitat based on species‐specific differences in blood oxygen affinity
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K. A. S. Mislan Curtis A. Deutsch Richard W. Brill John P. Dunne Jorge L. Sarmiento 《Global Change Biology》2017,23(10):4019-4028
Oxygen concentrations are hypothesized to decrease in many areas of the ocean as a result of anthropogenically driven climate change, resulting in habitat compression for pelagic animals. The oxygen partial pressure, pO2, at which blood is 50% saturated (P50) is a measure of blood oxygen affinity and a gauge of the tolerance of animals for low ambient oxygen. Tuna species display a wide range of blood oxygen affinities (i.e., P50 values) and therefore may be differentially impacted by habitat compression as they make extensive vertical movements to forage on subdaily time scales. To project the effects of end‐of‐the‐century climate change on tuna habitat, we calculate tuna P50 depths (i.e., the vertical position in the water column at which ambient pO2 is equal to species‐specific blood P50 values) from 21st century Earth System Model (ESM) projections included in the fifth phase of the Climate Model Intercomparison Project (CMIP5). Overall, we project P50 depths to shoal, indicating likely habitat compression for tuna species due to climate change. Tunas that will be most impacted by shoaling are Pacific and southern bluefin tunas—habitat compression is projected for the entire geographic range of Pacific bluefin tuna and for the spawning region of southern bluefin tuna. Vertical shifts in P50 depths will potentially influence resource partitioning among Pacific bluefin, bigeye, yellowfin, and skipjack tunas in the northern subtropical and eastern tropical Pacific Ocean, the Arabian Sea, and the Bay of Bengal. By establishing linkages between tuna physiology and environmental conditions, we provide a mechanistic basis to project the effects of anthropogenic climate change on tuna habitats. 相似文献
10.
R. M. Bevan P. J. Butler 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1994,164(5):349-354
Arterial blood pressure was monitored in voluntarily diving tufted ducks. Mean arterial blood pressure while diving increased during the pre-dive tachycardia, fell to resting levels on submersion, then gradually increased before peaking on surfacing. Estimated total peripheral resistance fell during the pre-dive and post-dive tachycardia, presumably to allow the oxygen stores to be loaded and replenished respectively and/or for carbon dioxide levels to be reduced. Changes in mean arterial blood pressure and total peripheral resistance suggest that peripheral vasoconstriction occurs in some vascular beds during a dive. An increase in arterial blood pressure (and therefore perfusion pressure) may be employed to increase blood flow and oxygen delivery to the active leg muscles.Abbreviations ecg
Electrocardiogram, f
H, heart rate
- MABP
mean arterial blood pressure
-
P
b
blood pressure(s)
- TPR
total peripheral resistance
-
V
b
cardiac output 相似文献
11.
Tetrapolar rheography according to Kubicek has been used to estimate the adaptive capacity of the cardiovascular system in 150 five- to seven-year-old children at rest and during mental load. Mental load evokes two variants of stroke volume (SV) responses, one of them characterized by an increase in the SV, and the other, by a decrease in the SV and an increase in the diastolic blood pressure (BPd). Irrespective of the direction of the change in the SV, short-term adaptation to mental load in most five- to seven-year-old children does not stress the mechanisms of the cardiovascular system control and is generally favorable. In 13–15% of the children examined, short-term adaptation to mental load considerably stressed the cardiovascular system control. This is expressed in increased systolic blood pressure (BPs), BPd, and heart rate (HR); decreased CV and cardiac output (Q); and a prolonged restoration period for most central hemodynamic parameters. 相似文献
12.
Wesley W. Weathers 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1976,105(2):173-184
Summary The influence of temperature on blood viscosity and consequently on the potential for oxygen transport by blood was determined using a controlled flow, variable pressure tube viscometer, and blood from adult bullfrogs. Blood viscosity was determined as a function of hematocrit and temperature, and oxygen capacity was determined as a function of hematocrit. These data were used to describe 1) the potential for oxygen transport in the tube viscometer, and 2) the relation between the optimal hematocrit, the hematocrit which provided the greates oxygen transport, and temperature. The optimal hematocrit increased at a rate of 0.237% per °C increase in temperature. This value is close to the rate of change inin vivo hematocrit of 0.246 and 0.240% per °C increase in body temperature (Tb) observed in winter bullforgs acclimated to 5 and 20°C, respectively. During the summer the hematocrit ratio showed no consistent relation to Tb. These results suggest that in bullfrogs the cardiovascular adjustments to change in Tb involve the optimal hematocrit in winter, but not in summer. 相似文献
13.
Kazuoki Kondo Tetsuji Okuno Takao Saruta Eiichi Kato 《Prostaglandins & other lipid mediators》1979,17(5):769-774
The effects of intraventricularly administered prostaglandins I2 (PGI2), E2 (PGE2), F2α (PGF2α) and indomethacin on systemic blood pressure were investigated in conscious rats. PGI2 (1.25 – 10 g/kg) decreased blood pressure in a dose-related manner, whereas PGE2 (100 – 1000 ng/kg) dose-dependently increased blood pressure. Both PGF2α (0.31 – 20 μg/kg) and indomethacin (0.625 – 40 μg/kg) had no effects on blood pressure. These results indicate that intraventricular injection of PGI2 or PGE2 can induce significant changes in blood pressure, while endogenous prostaglandins synthesized in the brain seem to play a minor role in direct regulation of systemic blood pressure in the rat. 相似文献
14.
PurposeFluid management using a body composition monitor (BCM) based on bioimpedance spectroscopy has been found to be beneficial for maintenance hemodialysis (MHD) patients. Our purpose was to provide a management procedure for the adjustment of post-dialysis overhydration (OHpost) and to evaluate whether this approach could improve blood pressure.MethodsPost-dialysis fluid status was assessed weekly using the BCM. The reference value of OHpost and the flow procedure for post-dialysis target weight (PDTW) adjustment were established via measurements of OHpost in 60 normotensive MHD patients. In the interventional study, we adjusted the PDTW of hypertensive patients to the optimal OHpost range, with a 0.2–0.5 kg change in PDTW per week.ResultsThis observational study included 130 anuric MHD patients, of whom 60 were in the pre-dialysis systolic blood pressure (sBPpre) < 140 mmHg group. On multivariate logistic regression analysis, we found that only OHpost was significantly associated with sBPpre ≥ 140 mmHg (odds ratio = 2.293, p = 0.000). Patients in the OHpost < ?1.8 L group were mainly male and younger, and had higher post-dialysis diastolic blood pressure, ultrafiltration volume, levels of nutrition markers (serum albumin and creatinine), body mass index, and lean tissue index (LTI). On multiple stepwise regression analysis, only the change in LTI was found to be an independent predictor of OHpost [R2 0.208, β = ?0.196, 95% CI (?0.296, ?0.095), p < 0.001]. The reference value of OHpost was found to deviate by ? 2.5–0.5 L from that of normotensive patients. At the end of the study, the systolic blood pressure of 38 patients was less than 140 mmHg after PDTW adjustment. The changes in OHpost from the initial to last adjustment were significant (t = 5.431, p < 0.001), with a substantial decrease in the sBPpre (t = 11.208, p < 0.001).ConclusionsAssessment of OHpost and LTI using a BCM with a patient-specific optimal PDTW adjustment flow can lead to significantly better control of hypertension in anuric MHD patients. 相似文献
15.
Grzegorz Bilo Miriam Revera Maurizio Bussotti Daniele Bonacina Katarzyna Styczkiewicz Gianluca Caldara Alessia Giglio Andrea Faini Andrea Giuliano Carolina Lombardi Kalina Kawecka-Jaszcz Giuseppe Mancia Piergiuseppe Agostoni Gianfranco Parati 《PloS one》2012,7(11)
Slow deep breathing improves blood oxygenation (SpO2) and affects hemodynamics in hypoxic patients. We investigated the ventilatory and hemodynamic effects of slow deep breathing in normal subjects at high altitude. We collected data in healthy lowlanders staying either at 4559 m for 2–3 days (Study A; N = 39) or at 5400 m for 12–16 days (Study B; N = 28). Study variables, including SpO2 and systemic and pulmonary arterial pressure, were assessed before, during and after 15 minutes of breathing at 6 breaths/min. At the end of slow breathing, an increase in SpO2 (Study A: from 80.2±7.7% to 89.5±8.2%; Study B: from 81.0±4.2% to 88.6±4.5; both p<0.001) and significant reductions in systemic and pulmonary arterial pressure occurred. This was associated with increased tidal volume and no changes in minute ventilation or pulmonary CO diffusion. Slow deep breathing improves ventilation efficiency for oxygen as shown by blood oxygenation increase, and it reduces systemic and pulmonary blood pressure at high altitude but does not change pulmonary gas diffusion. 相似文献
16.
Tetsuji Okuno Kazuoki Kondo Hiromichi Suzuki Takao Saruta 《Prostaglandins & other lipid mediators》1980,19(6):855-864
The effects of prostaglandins E2 (PGE2), I2 (PGI2) and F2α (PGF2α), arachidonic acid and indomethacin on pressor responses to norepinephrine were examined in conscious rats. Intravenously infused PGE2 (0.3, 1.25 μg/kg/min), PGI2 (50, 100 ng/kg/min), PGF2α (1.8, 5.4 μg/kg/min) and arachidonic acid (0.7, 1.4 mg/kg/min) did not change the basal blood pressure. Both PGE2 and PGI2 significantly attenuated pressor responses to norepinephrine, whereas PGF2α significantly potentiated them. Arachidonic acid, a precursor of the prostaglandins (PGs), significantly attenuated pressor responses to norepinephrine. Since the attenuating effect of arachidonic acid was completely abolished by the pretreatment with indomethacin (5 mg/kg), arachidonic acid is thought to exert an effect through its conversion to PGs. On the contrary, intravenously injected indomethacin (0.2–5.0 mg/kg) facilitated pressor responses to norepinephrine in a dose-related manner without any direct effect on the basal blood pressure. These results suggest that endogenous PGs may participate in the regulation of blood pressure by modulating pressor responses to norepinephrine in conscious rats. 相似文献
17.
Song Dekun Marczis Janos Olano Marta Kovach Arisztid G. B. Wilson David F. Pastuszko Anna 《Neurochemical research》1997,22(9):1111-1117
This study investigated the relationships between blood pressure, cortical oxygen pressure, and extracellular striatal dopamine in the brain of adult cats during hemorrhagic hypotension and re-transfusion. Oxygen pressure in the blood of the cortex was measured by the oxygen dependent quenching of phosphorescence and extracellular dopamine, dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) by in vivo microdialysis. Following a 2 h stabilization period after implantation of the microdialysis probe in the striatum, the mean arterial blood pressure (MAP) was decreased in a stepwise manner from 132 ± 2 Torr (control) to 90 Torr, 70 Torr and 50 Torr, holding the pressure at each level for 15 min. The whole blood was then retransfused and measurements were continued for 90 min. As the MAP was lowered there was a decrease in arterial pH, from a control value of 7.37 ± 0.05 to 7.26 ± 0.06. The PaCO2 decreased during bleeding from 32.3 ± 4.8 Torr to 19.6 ± 3.6 Torr and returned to 30.9 ± 3.9 Torr after retransfusion. The PaO2 was 125.9 ± 15 Torr during control conditions and did not significantly change during bleeding. Cortical oxygen pressure decreased with decrease in MAP, from 50 ± 2 Torr (control) to 42 ± 1 Torr, 31 ± 2 Torr and 22 ± 2 Torr, respectively. A statistically significant increase in striatal extracellular dopamine, to 2,580 ± 714% of control was observed when MAP decreased to below 70 Torr and cortical oxygen pressure decreased to below 31 Torr. When the MAP reached 50 Torr, the concentration of extracellular dopamine increased to 18,359 ± 2,764% of the control value. A statistically significant decrease in DOPAC and HVA were observed during the last step of bleeding. The data show that decreases in systemic blood pressure result in decrease in oxygen pressure in the microvasculature of the cortex, suggesting vascular dilation is not sufficient to result in a full compensation for the decreased MAP. The decrease in cortical oxygen pressure to below 32 Torr is accompanied by a marked increase in extracellular dopamine in the striatum, indicating that even such mild hypoxia can induce significant disturbance in brain metabolism. 相似文献
18.
《Chronobiology international》2013,30(2):205-216
Congestive heart failure is associated with a loss of circadian and short-term variability in blood pressure and heart rate. In order to assess the contribution of elevated cardiac sympathetic activity to the disturbed cardiovascular regulation, we monitored blood pressure and heart rate in mice with cardiac overexpression of the β1-adrenoceptor prior to the development of overt heart failure. Telemetry transmitters for continuous monitoring of blood pressure and heart rate were implanted in 8 to 9-week-old wildtype and transgenic mice, derived from crosses of heterozygous transgenic (line β1TG4) and wildtype mice. Cardiovascular circadian patterns were analyzed under baseline conditions and during treatment with propranolol (500 mg/L in drinking water). Short-term variability was assessed by spectral analysis of beat-to-beat data sampled for 30 min at four circadian times. Transgenic β1TG4 mice showed an increase in 24 h heart rate, while blood pressure was not different from wildtype controls. Circadian patterns in blood pressure and heart were preserved in β1TG4 mice. Addition of propranolol to the animals’ drinking water led to a reduction in heart rate and its 24 h variation in both strains of mice. Short-term variability in blood pressure was not different between wildtype and β1TG4 mice, but heart rate variability in the transgenic animals showed a rightward shift of the high-frequency component in the nocturnal activity period, suggesting an increase in respiratory frequency. In conclusion, the present study shows that both the circadian and the short-term regulation of blood pressure and heart rate are largely preserved in young, nonfailing β1-transgenic mice. This finding suggests that the loss of blood pressure and heart rate variability observed in human congestive heart failure cannot be attributed solely to sympathetic overactivity but reflects the loss of adrenergic responsiveness to changes in the activity of the autonomic nervous system. 相似文献
19.
Background
Carbon dioxide (CO2) is a recognized vasodilator of myocardial blood vessels that leads to changes in myocardial oxygenation through the recruitment of the coronary flow reserve. Yet, it is unknown whether changes of carbon dioxide induced by breathing maneuvers can be used to modify coronary blood flow and thus myocardial oxygenation. Oxygenation-sensitive cardiovascular magnetic resonance (CMR) using the blood oxygen level-dependent (BOLD) effect allows for non-invasive monitoring of changes of myocardial tissue oxygenation. We hypothesized that mild hypercapnia induced by long breath-holds leads to changes in myocardial oxygenation that can be detected by oxygenation-sensitive CMR.Methods and Results
In nine anaesthetized and ventilated pigs, 60s breath-holds were induced. Left ventricular myocardial and blood pool oxygenation changes, as monitored by oxygenation-sensitive CMR using a T2*-weighted steady-state-free-precession (SSFP) sequence at 1.5T, were compared to changes of blood gas levels obtained immediately prior to and after the breath-hold. Long breath-holds resulted in an increase of paCO2, accompanied by a decrease of paO2 and pH. There was a significant decrease of blood pressure, while heart rate did not change. A decrease in the left ventricular blood pool oxygenation was observed, which was similar to drop in SaO2. Oxygenation in the myocardial tissue however, was maintained throughout the period. Changes in myocardial oxygenation were strongly correlated with the change in paCO2 during the breath-hold (r = 0.90, p = 0.010).Conclusion
Despite a drop in blood oxygen levels, myocardial oxygenation is maintained throughout long breath-holds and is linearly correlated with the parallel increase of arterial CO2, a known coronary vasodilator. Breathing maneuvers in combination with oxygenation-sensitive CMR may be useful as a diagnostic test for coronary artery function. 相似文献20.
Osmotic minipumps were used to infuse carbachol chloride (1.23 μg/hr), echothiophate iodide (0.5 μg/hr), histamine dihydrochloride (10 μg/hr), prostaglandin E2 (1.0 μg/hr) and thyrotropin-releasing hormone (0.5 and 5.0 μg/hr) solutions into the cerebral ventricles of unanesthetized rats and blood pressure was measured by the tail-cuff method. Histamine dihydrochloride, prostaglandin E2 and thyrotropin-releasing hormone produced an initial rise in blood pressure, but were not effective in producing sustained elevations in blood pressure. Carbachol infusions elevated blood pressure throughout the 7-day infusion period when results were compared to saline-infused animals. Infusions of echothiophate iodide, an anticholinesterase agent, produced an initial rise in blood pressure but these pressor effects were not sustained. In animals infused with echothiophate for 7 days, the pressor response to a challenge dose of echothiophate was diminished. 相似文献