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1.
The dihydrogenated alkaloids of ergot, dihydroergocornine (DHO 180) and an equal mixture of dihydroergocornine, dihydroergocristine and dihydroergokryptine known as CCK 179 have been found to be therapeutic adjuncts in the medical treatment of peripheral vascular diseases. Their action is primarily that of adrenergic blockage, although depression of the brain stem is to be considered. The mixture of alkaloids (CCK 179) was found to be more effective than a single alkaloid, dihydroergocornine (DHO 180). A greater number of patients were benefited, relief of symptoms was greater and the dosage easier to establish. A favorable therapeutic response of clinical significance with the mixture was obtained in approximately 60 per cent of all cases investigated. It was of greater benefit in the organic occlusive diseases, where a larger percentage of favorable responses was obtained than in the purely vasospastic disorders. Orally and subcutaneously, CCK 179 exhibited vasodilating properties which compared favorably with paravertebral and peripheral nerve block, reflex heat, alcohol and sympathectomy. Surface temperatures were elevated, oscillometric readings increased and tolerance to cold increased in a statistically significant number of cases. Effects of sympathectomies were frequently enhanced. Following subcutaneous administration, increased surface temperatures of the extremities of one to two hours' duration were obtained in 90 per cent of all cases.Paresthesias, nocturnal cramps and intermittent claudication were improved. A sense of well-being was occasionally exhibited. Blood pressure and pulse rates were rarely affected. Blood pressure was lowered in normotensive patients, but was rarely changed in hypertensive patients. Symptoms of overdosage appeared after two to three months of continuous therapy. These were manifested by lowered surface temperatures, decreased tolerance to cold, return of intermittent claudication and occasionally by vague general discomfort. These symptoms disappeared on cessation of therapy. Improvement frequently followed. In only one case was there an immediate reaction. Following subcutaneous administration of CCK, blood pressure and pulse rate increased and oscillometric readings and surface temperatures decreased. Frequent courses of therapy with interruptions were necessary for maintenance of improvement.  相似文献   

2.
A comparison of nicotinic acid, a non-narcotic analgesic and a series of injectable and oral ergot preparations tested by various methods in treating 40 patients with typical migraine indicate that ergot alkaloids are far superior in producing symptomatic relief.A comparison of ergotamine tartrate, dihydroergotamine (DHE-45) and dihydroergocornine (DHO-180) indicated that ergotamine tartrate is the most effective and perhaps the most toxic, DHE-45 is slightly less effective and considerably less toxic, and that DHO-180 is the least effective but also the least toxic. When given orally, these alkaloids were about half as effective as when given by injection. EC-110 (ergotamine nitrate with caffeine) was the most effective.DHO-180 in liquid form, given daily for one month, had a marked preventive effect on migraine attacks.  相似文献   

3.
A comparison of nicotinic acid, a non-narcotic analgesic and a series of injectable and oral ergot preparations tested by various methods in treating 40 patients with typical migraine indicate that ergot alkaloids are far superior in producing symptomatic relief.A comparison of ergotamine tartrate, dihydroergotamine (DHE-45) and dihydroergocornine (DHO-180) indicated that ergotamine tartrate is the most effective and perhaps the most toxic, DHE-45 is slightly less effective and considerably less toxic, and that DHO-180 is the least effective but also the least toxic. When given orally, these alkaloids were about half as effective as when given by injection. EC-110 (ergotamine nitrate with caffeine) was the most effective.DHO-180 in liquid form, given daily for one month, had a marked preventive effect on migraine attacks.  相似文献   

4.
Severe hypoglycemia with isoelectric EEG induced extensive deterioration of the energy state and gross alteration of amino acid contents on the rat cerebral and cerebellar cortex. During recovery, tissue glucose concentration returned to normal, while both lactate and pyruvate concentrations increased to above normal. In the recovery period, the ATP concentration increased but the adenine nucleotide pool remained reduced, even if the ADP and AMP contents were close to normal. Phosphocreatine was restored to normal concentration with reciprocal changes in creatine content. During recovery there was a rise in glutamate and glutamine concentrations, gamma-aminobutyrate content returning to normal value. Ammonia and aspartate decreased below normal, while alanine increased above normal. The effect of some pharmacological agents on the posthypoglycemic recovery was tested: (a) Ergot alkaloids (dihydroergocristine, dihydroergocriptine, dihydroergocornine); (b) Vinca minor alkaloids (vincamine TPS, (–) eburnamonine); (c) Rauwolfia serpentina alkaloids (reserpine, raubasine); (d) synthetic agent (piracetam). During the posthypoglycemic recovery, these different agents exhibited different, or even contrasting, interferences on glycolytic metabolites, amino acids and energy-rich phosphates. The metabolic alterations in the cerebellar cortex were qualitatively of the same character of those in neocortex. However, the metabolic alterations were less extensive and more sensitive to drug action.  相似文献   

5.
目的:本实验观察胆囊收缩素(CCK)在福尔马林致痛大鼠感觉信息传递中的作用。方法:用免疫组织化学技术,分别观察阴性对照、生理盐水、福尔马林致痛后1h和福尔马林致痛后3h大鼠脊髓背角的感觉神经元神经肽CCK表达的变化。结果:大鼠足底注射福尔马林1h后,脊髓背角Ⅰ、Ⅱ层神经元CCK表达阳性细胞数明显增加(P〈0.01),且注射侧阳性细胞数明显高于非注射侧。注射福尔马林1h后,注射侧和非注射侧CCK表达阳性细胞的半定量光密度均值分别是0.397±0.014和0.295±0.007,差异有显著性(P〈0.01);注射福尔马林3h后,注射侧和非注射侧脊髓背角CCK表达阳性细胞的半定量光密度均值分别是0.366±0.009和0.303±0.005,差异仍有显著性(P〈0.01)。结论:福尔马林致痛大鼠脊髓CCK表达阳性细胞的半定量光密度均值增加,进一步证实CCK在炎性痛信息传递通路的多个环节中参与了痛觉调制。  相似文献   

6.
The long, occult phase of pre-invasive carcinoma of the uterine cervix provides the clinician with his greatest opportunity in the actual prophylaxis of invasive cancer. By the use of four-quadrant biopsies and Papanicolaou smears, the authors increased by almost 20 times the frequency of diagnosis of preinvasive carcinoma of the uterine cervix.Radiation therapy of invasive carcinoma in 147 patients produced five-year “cure” in 84 per cent of stage I cases, 65 per cent of stage II cases. The over-all rate for stages I to IV, inclusive, was 51 per cent.Surgical management of this form of cancer, with preservation of the urinary tract, is an inadequate operation as judged by the extirpative standards observed in operations for cancer at other major anatomical sites.Improvements in technique of irradiation, more accurate measurements of depth dosage at critical sites, and more uniform dosage throughout the parametrial areas, have decreased the incidence of major complications of irradiation.Radical panhysterectomy and pelvic node dissection should be reserved for patients proved to have radioresistant lesions.The application of routine block dissection of pelvic nodes for Stage I and Stage II lesions, clinically controlled by irradiation, is of doubtful theoretic, and no evident practical value.Subject to future evaluation, pelvic eviscerative procedures seem to offer some salvage in cases of recurrent (occasionally primary) advanced lesions in rigidly selected patients.  相似文献   

7.
A trial of methyldopa in hypertension was conducted in 60 patients for a mean time of 9.4 months. Initially, four different dosages of methyldopa were studied and blood pressure was significantly lowered in the supine and standing positions. Standing blood pressure was significantly reduced more than supine. An average of 5.2 visits passed before maintenance blood pressure was obtained. There was no significent evidence of deterioration during the duration of this study. Side effects were mild. Only two patients voluntarily requested discontinuance of this study. Tolerance to the drug occurred and approximately 50 per cent of the patients no longer had a significant blood pressure reduction to methyldopa alone by the end of the study. Methyldopa appears to be a significant addition to the drug therapy of hypertension.  相似文献   

8.
The humoral control of secretion of the proteolytic enzymes trypsin and chymotrypsin was studied in yellowtail (Seriola quinqueradiata). In vitro trials were performed to investigate the effects of cholecystokinin (CCK) and two commercially available gastrin peptides. Isolated preparations of pyloric caeca/pancreas release trypsin and chymotrypsin when incubated with cholecystokinin (CCK) at 10 microM and gastrin I (G1) at 50 microM after 15 min of incubation. On the other hand, G1 at 10 microM and gastrin-related peptide (G2) did not enhance trypsin and chymotrypsin secretion. The studies concerning the CCK effects at different incubation temperatures have shown that trypsin and chymotrypsin secretion at 25 degrees C was stimulated by CCK after 15 min, while at 10, 15 and 20 degrees C the stimulatory effects of CCK were observed only after 30 min of incubation. The CCK effects were increased at higher incubation temperatures and longer incubation periods.  相似文献   

9.
In the pyrimidine biosynthetic pathway, N-carbamyl-L-aspartate (CA-asp) is converted to L-dihydroorotate (DHO) by dihydroorotase (DHOase). The mechanism of this important reaction was probed using primary and secondary 15N and 13C isotope effects on the ring opening of DHO using isotope ratio mass spectrometry (IRMS). The reaction was performed at three different temperatures (25, 37, and 45 degrees C for hamster DHOase; 37, 50, and 60 degrees C for Bacillus caldolyticus), and the product CA-asp was purified for analysis. The primary and secondary kinetic isotope effects for the ring opening of the DHO were determined from analysis of the N and C of the carbamyl group after hydrolysis. In addition, the beta-carboxyl of the residual aspartate was liberated enzymatically by transamination to oxaloacetate with aspartate aminotransferase and then decarboxylation with oxaloacetate decarboxylase. The 13C/12C ratio from the released CO2 was determined by IRMS, yielding a second primary isotope effect. The primary and secondary isotope effects for the reaction catalyzed by DHOase showed little variation between enzymes or temperatures, the primary 13C and 15N isotope effects being approximately 1% on average, while the secondary 13C isotope effect is negligible or very slightly normal (>1.0000). These data indicate that the chemistry is at least partially rate-limiting while the secondary isotope effects suggest that the transition state may have lost some bending and torsional modes leading to a slight lessening of bond stiffness at the carbonyl carbon of the amide of CA-asp. The equilibrium isotope effects for DHO --> CA-asp have also been measured (secondary 13K(eq) = 1.0028 +/- 0.0002, primary 13K(eq) = 1.0053 +/- 0.0003, primary 15K(eq) = 1.0027 +/- 0.0003). Using these equilibrium isotope effects, the kinetic isotope effects for the physiological reaction (CA-asp --> DHO) have been calculated. These values indicate that the carbon of the amide group is more stiffly bonded in DHO while the slightly lesser, but still normal, values of the primary kinetic isotope effect show that the chemistry remains at least partially rate-limiting for the physiological reaction. It appears that the ring opening and closing is the slow step of the reaction.  相似文献   

10.
The intracellular Na ion activity (aiNa) and the contractile tension (T) of sheep cardiac Purkinje fibers were simultaneously measured employing recessed-tip Na+-selective glass microelectrodes and a mechano-electric transducer. The aiNa of 6.4 +/- 1.6 mM (mean +/- SD, n = 56) was obtained in fibers perfused with normal Tyrode's solution. The changes in aiNa and T were measured during and after the exposure of fibers to a cardiac glycoside, dihydro-ouabain (DHO) in concentrations between 5 X 10(-8) M and 10(-5) M. The exposure time to DHO was 15 min. Both aiNa and T did not change in fibers exposed to 5 X 10(-8) M DHO, and the threshold concentration for the effect of DHO appeared to be around 10(-7) M. In DHO concentrations greater than the threshold, the increases in aiNa and T strongly correlated during the onset of DHO effects. The recoveries of aiNa and T were variable and slow, being dependent on the DHO concentration. In those fibers which recovered from the effects of DHO, the time-course of aiNa recovery was similar to that of T recovery. In fibers exposed to DHO of 5 X 10(-6) M or greater, the apparent toxic effects were observed in both action potential and contraction after an initial increase in T. The fibers manifesting the apparent toxic effects has a aiNa of approximately 30 mM or greater. The results of this study indicate that the increase in aiNa is associated with the positive inotropic action of the cardiac glycoside.  相似文献   

11.
低浓度双氢哇巴因对豚鼠心室肌细胞内游离钙浓度的影响   总被引:6,自引:1,他引:5  
Yin JX  Wang YL  Li Q  Shang ZL  Su SW 《生理学报》2002,54(5):385-389
用激光共聚焦显微镜检查研究低浓度双氢哇巴因(DHO)对豚鼠心室肌细胞内钙浓度([Ca^2 ]i)的影响。DHO 1fmol/L-1 mmol/L可增加心室肌细胞的[Ca^2 ]i,尤其以10pmol/L DHO为显著,Nisoldipine,EGTA或TTX可分别部分抑制10pmol/L DHO的作用,去除胞外K^ 和Na^ 后,上述作用仍存在,以上结果表明,低浓度DHO中通过激活钙通道和TTX敏感的钠通道,或许还可直接促进胞内钙释放来增加[Ca^2 ]i,并有不依赖Na^ /K^ 泵而升高[Ca^2 ]i的作用。  相似文献   

12.
Dihydroorotate dehydrogenases (DHODs) oxidize dihydroorotate (DHO) to orotate (OA) using the FMN prosthetic group to abstract a hydride equivalent from C6 and a protein residue (cysteine for class 1A DHODs) to deprotonate C5. The fundamental question of whether the scission of the two DHO C-H bonds is concerted or stepwise was addressed for the class 1A enzyme from Lactococcus lactis by determining kinetic isotope effects (KIEs) on flavin reduction in anaerobic stopped-flow experiments. Isotope effects were determined at two pH values. At pH 7.0, KIEs were approximately 2-fold for DHO labeled singly at the 5-position or the 6-position and approximately 4-fold for DHO labeled at both the 5- and 6-positions. At pH 8.5, the KIEs observed for DHO labeled at the 5-position, the 6-position, and the 5- and 6-positions were approximately 2-, approximately 3-, and approximately 6-fold, respectively. These isotope effects are consistent with a concerted oxidation of DHO. The pH dependence of reduction was also determined, and a pKa of 8.3 was found. This pKa can be attributed to the ionization of the active site cysteine which deprotonates C5 of DHO during the reaction. To further investigate the importance of the active site base, two site-directed mutants were also studied: Cys130Ala (removal of the active site base) and Cys130Ser (replacement with the active site base used by class 2 DHODs). Both mutant enzymes exhibited binding affinities for DHO similar to that of the wild-type enzyme. Reduction of both mutants was extremely slow compared to that of the wild type; the rate of reduction increased with pH, showing no sign of a plateau. Interestingly, double-deuterium isotope effects on the Cys130Ser mutant also showed a concerted mechanism for flavin reduction.  相似文献   

13.
Oscillometric blood pressures are derived from the amplitude envelope of oscillometric pulses generated in an occlusive cuff during cuff inflation or deflation; one factor which will affect the characteristics of these pulses is the size of the cuff bladder. Because limiting values are stipulated in recommendations and standards for bladder sizes, there is a wide variety of acceptable cuff sizes for any particular application. An experimental and theoretical study was undertaken to show the dependence of oscillometric blood pressures on bladder size. Actual cuff-arm compliance data were obtained from two subjects for two cuffs of different bladder size. Theoretical analysis was then applied to the data to predict the effects of different bladder sizes on the characteristics of the pulses. The results show that cuff-arm compliance and bladder size interact to affect the pulse amplitude and hence oscillometric blood pressure determination. These results suggest that blood pressures obtained using the oscillometric method may vary depending on cuff size, and in particular that replacement cuffs for oscillometric non-invasive blood pressure monitors should be chosen carefully.  相似文献   

14.
倪宏  王守彪  徐珞  唐明 《动物学报》2001,47(2):179-181,T001
本实验用原位杂交法,对听源性遗传癫痫易感大鼠(P77PMC)癫痫发作前,单次癫痫发作和多次发作时大脑颞皮层CCK mRNA阳性信号进行了检测,结果显示:(1)单次和多次癫痫发作后颞皮层CCK mRNA阳性神经元数量明显增加(P<0.01);(2)多次癫痫发作者上述脑区CCK mRNA阳性神经元数量较单次癫痫发作有明显的下降(P<0.01),大脑颞皮层CCK mRNA增高表明,CCK mRNA在癫痫发作过程中起了某种作用,多次癫痫发作大鼠CCK mRNA表达降低提示,单次和多次癫痫发作时大脑皮层CCK mRNAl转录的调控可能存在不同的机制。  相似文献   

15.
Lactic acid production by rat retina in a medium containing phosphate was studied chemically. One half as much lactic acid was found as in a medium containing bicarbonate. In our experience the rate of respiration in a phosphate medium was sensitive to oxygen tension, for it was 38 per cent lower at 10 per cent and 51 per cent lower at 5 per cent oxygen than at 100 per cent oxygen. Previously Laser had reported no decrease in respiration at 5 per cent oxygen in phosphate medium. In phosphate medium, when the oxygen tension was varied, respiration and glycolysis bore a reciprocal relationship to each other. In bicarbonate medium, when the oxygen tension was lowered from 95 per cent to 5 per cent there was no significant change in the respiration, but glycolysis was increased nearly to the anaerobic level. This agrees with the earlier experiment of Laser in bicarbonate medium and adds support to his conclusion that the rate of glycolysis is controlled by oxygen tension rather than by the rate of respiration, under the conditions of the experiment.  相似文献   

16.
Southwest Australian Banksia woodlands are highly diverse plant communities that are threatened by drought‐ or temperature‐induced mortality due to the region's changing climate. We examined water relations in dominant Banksia menziesii R. Br. trees using magnetic leaf patch clamp pressure (ZIM‐) probes that allow continuous, real‐time monitoring of leaf water status. Multiple ZIM‐probes across the crown were complemented by traditional ecophysiological measurements. During summer, early stomatal downregulation of transpiration prevented midday balancing pressures from exceeding 2.5 MPa. Diurnal patterns of ZIM‐probe and pressure chamber readings agreed reasonably well, however, ZIM‐probes recorded short‐term dynamics, which are impossible to capture using a pressure chamber. Simultaneous recordings of three ZIM‐probes evenly spaced along leaf laminas revealed intrafoliar turgor gradients, which, however, did not develop in a strictly basi‐ or acropetal fashion and varied with cardinal direction. Drought stress manifested as increasing daily signal amplitude (low leaf water status) and occasionally as rising baseline at night (delayed rehydration). These symptoms occurred more often locally than across the entire crown. Microclimate effects on leaf water status were strongest in crown regions experiencing peak morning radiation (East and North). Extreme spring temperatures preceded the sudden death of B. menziesii trees, suggesting a temperature‐ or humidity‐related tipping point causing rapid hydraulic failure as evidenced by collapsing ZIM‐probe readings from an affected tree. In a warmer and drier future, increased frequency of B. menziesii mortality will result in significantly altered community structure and ecosystem function.  相似文献   

17.
1. The effect of dietary amino acids and protein on cholecystokinin (CCK) release into plasma was investigated in chicks by feeding a meal through a stomach tube, followed by the CCK determination with specific CCK-8 antibody. 2. The results showed that both isolated soya protein and an amino acid mixture simulating the amino acid composition of the soya protein increased the release of CCK, though to a lesser extent with a delayed response in the former, when added to a protein-free diet. 3. Among amino acids added singly to the protein-free diet, phenylalanine was more efficient than arginine and valine, exerting a response almost identical to the complete amino acid mixture.  相似文献   

18.
为研究大口黑鲈(Micropterus salmoides) 胆囊收缩素(Cholecystokinin, CCK)和其受体(Cholecystokinin receptor, CCKR)基因在摄食活动中的功能, 研究通过克隆得到CCK1、CCK2、CCK1R和CCK2R基因的编码区序列, 其长度分别为414、387、1368和1359 bp, 分别编码137、128、455和452个氨基酸。荧光定量结果表明CCK1和CCK2基因均在脑组织中高表达, 其次为肠道组织, 而CCK1R和CCK2R基因分别在胆囊和脑组织中高表达。在摄食后24h内, CCK1、CCK2、CCK1R和CCK2R基因的相对表达量呈先升高后下降趋势, 其中CCK1、CCK1R和CCK2R基因在摄食后3h相对表达量达到最高值, 而CCK2基因在摄食后12h相对表达量达到最高值(P<0.05)。禁食过程中CCK1、CCK1R和CCK2R基因相对表达量在禁食14d时显著升高(P<0.05)。复投喂后CCK1、CCK1R和CCK2R基因的相对表达趋势与餐后表达趋势相似, 呈先升高后降低趋势。但在禁食和复投喂过程中CCK2基因相对表达量并无显著变化。综上所述, 研究结果推测CCK1基因可能与CCK1R、CCK2R基因结合, 作为饱腹信号因子, 通过抑制食欲调控大口黑鲈摄食、消化等生理过程; 而CCK2基因可能作为短期食欲因子调节摄食活动。研究结果可为大口黑鲈摄食活动调节提供理论依据。  相似文献   

19.
A new method to assay the mitochondrial pyrimidine de novo enzyme, dihydroorotate (DHO) dehydrogenase, which catalyzes the dehydrogenation of DHO, with orotic acid as the product was developed. The assay was optimized using a rat liver mitochondrial preparation. Orotic acid was quantified with high-performance liquid chromatography using an anion-exchange column (Partisil-SAX) with uv detection at 280 nm. Isocratic elution with low phosphate buffer at pH 4.0 was used. The detection limit was 20 pmol per injection, which is comparable to previously described radiometric assays. The HPLC assay was compared with a spectrophotometric assay measuring orotic acid formation in a deproteinized reaction mixture. Absorbance was measured at the optimal wavelength for orotic acid, 278.5 nm. This assay is less sensitive and less specific than the HPLC assay, which can also detect UMP which might be formed from orotic acid in whole homogenates. With both assays kinetic parameters of the enzyme were determined. In the high concentration range (80-1000 microM) both Km and Vmax values were comparable. With the HPLC assay the concentration range was extended down to 12 microM and initial rates could be determined. The apparent Km was about 12 microM. The HPLC assay is also suitable for use in the study of inhibition of DHO dehydrogenase.  相似文献   

20.
The effects of three subcutaneous injections of 3 nmol/100 g body weight of the cholecystokinin type 2 (CCK2) receptor agonist pentagastrin on adrenocorticotrophic hormone (ACTH) and corticosterone secretion and proliferative activity of regenerating rat adrenal cortex were investigated. Pentagastrin did not alter either ACTH and corticosterone plasma concentrations or the adrenal mitotic index at day 5 of regeneration. In contrast, it increased (by about 50%) the adrenal mitotic index at day 8 of regeneration, and the effect was blocked by the simultaneous administration of equimolar doses of the CCK2-receptor antagonist PD-135,158. It is suggested that the activation of CCK2 receptors exerts a growth promoting action on the regenerating rat adrenal cortex.  相似文献   

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