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1.
B. Lacarelle O. Blin C. Audebert P. Auquier H. Karsenty F. Horriere A. Durand 《European journal of clinical pharmacology》1994,46(5):477-478
The kinetics of a single i. v. dose of theophylline given either alone or with flumequine was studied in eight healthy volunteers. No statistically significant differences were observed in the pharmacokinetic parameters of theophylline (volume of distribution, elimination half-life, AUC, plasma clearance) following the two treatments.Pretreatment for 5 days with oral flumequine (400 mg, three times daily) had no significant effect on the disposition of a single i. v. dose of theophylline in healthy volunteers. 相似文献
2.
Liu Changning Zhao Feiyue Zhu Lixia Department of Physiology Institute of Acupuncture Moxibustion China Academy of Traditional Chinese Medicine Beijing China 《世界针灸杂志》1993,(2)
It has been extensively proved that electro-acupuncture elicit analgesia in bothextensive areas and local region via supraspinal structures and spinal cord.The present investigationwas to study the role of P_1-purinergic receptors in the spinal mechanisms of weak electroacupuncture-induced analgesia.Leg withdrawal latency(LWL)to noxious radiant heat focused on the ankle regionwas used to assess the effects of acupuncture and that of P_1-purinergic(adenosine)receptor antago-nists,theophylline and caffeine on the electro-acupuncture(EA)analgesia.EA prolonged the LWLby 16.7%±20.3%,with an after-effect lasting about 15 min.Both theophylline and caffeineblocked the EA-induced prolongation of LWL in a dose-dependent manner at the doses of 1.6-16 mg/kg.These results suggest that P_1-purinegic receptor is involved in the spinal mechanisms of weak EAproduced analgesia in the rat. 相似文献
3.
4.
D. Ukena C. G. Schirren K. -N. Klotz U. Schwabe 《Naunyn-Schmiedeberg's archives of pharmacology》1985,331(1):89-95
Summary Adenosine receptors in guinea pig lung were characterized by measurement of cyclic AMP formation and radioligand binding. 5-N-Ethylcarboxamidoadenosine (NECA) increased cyclic AMP levels in lung slices about 4-fold over basal values with an EC50 of 0.32 mol/l. N6-R-(–)-Phenylisopropyladenosine (R-PIA) was 5-fold less potent than NECA. 5-N-Methylcarboxamidoadenosine (MECA) and 2-chloroadenosine had EC50-values of 0.29 and 2.6 mol/l, whereas adenosine and inosine had no effect. The adenosine receptors in guinea pig lung can therefore be classified as A2 receptors. Several xanthine derivatives antagonized the NECA-induced increase in cyclic AMP levels. 1,3-Diethyl-8-phenylxanthine (DPX; K
i 0.14 mol/l) was the most potent analogue, followed by 8-phenyltheophylline (K
i 0.55 mol/l), 3-isobutyl-1-methylxanthine (IBMX; K
i 2.9 mol/l) and theophylline (K
i 8.1 mol/l). In contrast, enprofylline (1 mmol/l) enhanced basal and NECA-stimulated cyclic AMP formation. In addition, we attempted to characterize these receptors in binding studies with [3H]NECA. The K
D for [3H]NECA was 0.25 mol/l and the maximal number of binding sites was 12 pmol/mg protein. In competition experiments MECA (K
i 0.14 mol/l) was the most potent inhibitor of [3H]NECA binding, followed by NECA (K
i 0.19 mol/l) and 2-chloroadenosine (K
i 1.4 mol/l). These results correlate well with the EC50-values for cyclic AMP formation in lung slices. However, the K
i-values of R-PIA and theophylline were 240 and 270 mol/l, and DPX and 8-phenyltheophylline did not compete for [3H]NECA binding sites. Therefore, a complete characterization of A2 adenosine receptors by [3H]NECA binding was not achieved. In conclusion, our results show the presence of adenylate cyclase-coupled A2 adenosine receptors in lung tissue which are antagonized by several xanthines. 相似文献
5.
K. A. Alkadhi T. R. Brown M. H. Sabouni 《Naunyn-Schmiedeberg's archives of pharmacology》1984,328(1):16-19
Summary The effect of bath-applied adenosine on transmission in the isolated superior cervical ganglion of the rat was investigated. The compound post ganglionic action potential was recorded as an index of ganglionic transmission. Adenosine and 2-chloroadenosine were equipotent in producing a dose-dependent inhibition of the amplitude of the compound action potential. At the highest concentration tested (1 mM) adenosine and 2-chloroadenosine produced about 30% decrease in the amplitude of the compound action potential. This inhibitory effect was antagonized by theophylline (1 and 100 M) which by itself had no significant effect on ganglionic transmission. The adenosine uptake blocker dipyridamole (1 and 100 M) failed to potentiate the inhibitory action of adenosine. Both 4-aminopyridine (20 M) and high frequencies of stimulation (3, 10 and 20 Hz) were effective in nearly completely abolishing the inhibitory effect of adenosine on ganglionic transmission.The results suggest that the inhibitory effect of adenosine on ganglionic transmission may be the result of activation of presynaptic adenosine receptors in the ganglion. 相似文献
6.
The effects of adenosine A1 and A2 receptors on catalepsy were studied in mice. The adenosine agonists 5-N-ethylcarboxamide-adenosine (NECA), N6-phenylisopropyladenosine (PIA) and N6-cyclohexyladenosine (CHA) induced dose dependent catalepsy. The A1 adenosine antagonist 8-phenyltheophylline (8-PT) potentiated catalepsy induced by NECA, R-PIA and CHA. However, theophylline did not potentiate but inhibited the responses induced by NECA, R-PIA and CHA. Neither 8-PT nor theophylline alone has any effect on catalepsy in mice. It is concluded that catalepsy induced by the adenosine agonists may be due to A2 receptor stimulation and that the A1 antagonism may potentiate the response. 相似文献
7.
The experimental hepatic cirrhosis was induced either by bile duct ligation (BDL) or by pretreatment with dimethylnitrosamine
(DMNA). The pharmacokinetics of theophylline were studied after a single intravenous or a single oral administration. Using
the ultrafiltration method, protein-drug binding experiments were also carried out. The bilirubin level was several-fold increased
by BDL, but not by DMNA treatment. The albumin content was decreased in both cirrhotic groups. The total clearance (Clt, ml/kg/hr)
of theophylline in both hepatic cirrhosis groups significantly decreased and the terminal half-life (t1/2) in the cirrhotic rats was increased about two-fold after intravenous and oral administration. The volume of distribution
at steady state (Vdss, ml/kg) was increased slightly in the cirrhotic groups. Protein binding in BDL (8.67±4.85%) decreased
about four-folds, but in DMNA (73.00±9.85%) similar result, was observed as compared with the control. Increased free fraction
of theophylline did not increase the volume of distribution in BDL. Therefore decreased total body clearance of theophylline
was mainly due to decreased intrinsic clearance of theophylline in the liver. The absolute bioavailability of theophylline
in these experiments was between 63.8 and 72.8%(66.1% in BDL, 63.8% in Sham operated and Control, 72.8% in DMNA). These results
suggest that in the experimental hepatic cirrhosis model, administration route does not affect the disposition of theophylline. 相似文献
8.
头孢他啶对大鼠体内氨茶碱药动学的影响 总被引:3,自引:1,他引:3
目的通过检测茶碱在大鼠体内的血药浓度,分析头孢他啶对氨茶碱药动学参数的影响。方法12只大鼠随机分为两组,每组6只,给药前禁食12 h,对照组每只动物分别给予氨茶碱18 mg·kg-1,灌胃1次。实验组给予氨茶碱18 mg·kg-1,ig,并肌内注射头孢他啶100 mg·kg-1,分别在给药前及给药后0.08,0.50,1.00,2.00,4.00,6.00,8.00,12.00 h采血0.3~0.5 mL,置不抗凝离心试管内,离心(10 000 r·min-1),取血清60 μL,用全自动荧光偏振免疫分析仪测茶碱血药浓度。结果茶碱以一室药动学模型消除,头孢他啶与氨茶碱合用与单用氨茶碱比较,药动学参数无明显变化。结论头孢他啶在大鼠体内对氨茶碱药动学无显著影响。 相似文献
9.
辛大永 《实用中医内科杂志》2012,(18):25+28
[目的]观察宣肺通腑法治疗慢性阻塞性肺疾病急性加重期的临床疗效。[方法]将62例慢性阻塞性肺疾病急性加重期患者随机分为两组,治疗组32例,在西医常规治疗的基础上采用宣肺通腑法治疗;对照组30例,采用西医常规治疗。两组均以10d为1疗程,治疗1个疗程后,进行疗效判定。[结果]治疗组总有效率93.75%,对照组总有效率63.33%,治疗组优于对照组。[结论]宣肺通腑法治疗慢性阻塞性肺疾病急性加重期疗效显著。 相似文献
10.
Importance of drug type, tablet shape and added diluents on drug release kinetics from hydroxypropylmethylcellulose matrix tablets 总被引:3,自引:0,他引:3
James L. Ford Michael H. Rubinstein Fionan McCaul John E. Hogan Penny J. Edgar 《International journal of pharmaceutics》1987,40(3):223-234
The dissolution of 7 drugs from hydroxypropylmethylcellulose (HPMC) matrices have been examined to determine the time exponent (tn) required to produce linear dissolution profiles. A value of n = ˜ 0.67 was obtained for time-dependent release for soluble drugs, the precise values being 0.71, 0.65, 0.67 and 0.64 for promethazine hydrochloride, aminophylline, propranolol hydrochloride and theophylline, respectively. The insoluble drugs, indomethacin and diazepam, displayed values of n = 0.90 and 0.82 indicating a near zero-order release. Matrices containing tetracycline hydrochloride, however, showed a value of n = 0.45 and displayed complex release patterns and lower release rates than anticipated on the basis of solubility. Replacement of HPMC by calcium phosphate or lactose increased the dissolution rates of promethazine hydrochloride although the values of n were unchanged. Differences in release rates between lactose and calcium phosphate replacement occurred only when matrices contained high levels of the diluents. A straight line relationship existed between release rates and tablet surface area for HPMC tablets containing promethazine hydrochloride. 相似文献