Einflu\ eines Β1-Rezeptorenblockers auf die Plasmaspiegel des atrialen natriuretischen Peptids bei Patienten mit essentieller Hypertonie unter Ergometerbelastung

Summary In order to investigate the behaviour of atrial natriuretic peptide (ANP) in untreated mild to moderate essential hypertension and the influence of blood pressure normalisation by a ₁-receptor blocker a study was conducted in groups of normotensive and hypertensive middle aged subjects. 10 normal subjects and 10 patients with essential hypertension (WHO I–II) without any medication and on betaxolol monotherapy were studied at rest and during graded exercise. In addition the response of ANP, cyclic guanosine monophosphate (cGMP) and the renin-aldosterone-system was investigated.Normal subjects and hypertensive patients did not differ in ANP levels at rest and also responded with a comparable exercise dependent increase at all workload levels. A steady decrease of ANP was noticed during the recovery period in both groups. After-blocker treatment in the hypertensive patients ANP concentrations significantly rose, both at rest and more pronounced during exercise. cGMP reacted in a similar way but showed a more inert response. A counter-regulatory behaviour between ANP and PRA or aldosterone, as seen under volume shifts, could not be detected. These findings demonstrate that plasma ANP is not altered in untreated essential hypertension. Increased ANP levels in ₁-blocker treatment may contribute to its blood lowering effect.

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Abkürzungsverzeichnis ANP atriales natriuretisches Peptid - ALD Aldosteron - C_In Inulin Clearance - cGMP zyklisches Guanosinmonophosphat - irANP immunoreaktives atriales natriuretisches Peptid - PAH Paraaminohippursäure - PRA Plasma-Renin-Aktivität - RAA-System Renin-Angiotensin-Aldosteron-System - RBF renaler Blutflu - RIA Radioimmunoassay - RVR renaler Gefä\widerstand     

Evidence for the existence of two forms of α2A-adrenoceptors in the rat

Summary The _2A-adrenoceptors in rat spleen, kidney, spinal cord and cerebral cortex were studied using [³H]-RX821002 radioligand binding. In the spleen, spinal cord and cerebral cortex, the ligand bound to saturable sites with a K _d of about 1 nmol/l and capacities of 134, 240 and 290 fmol/mg protein, respectively. Computer modelling competition curves for 39 drugs, including those for _2A-, _2B- or _2C-adrenoceptor selective drugs, indicated that the sites labelled by [³H]-RX821002 in the spleen consisted of a single population of _2A-adrenoceptors. However, the competition curves for guanoxabenz were definitely biphasic and resolved into two site fits, indicating that guanoxabenz was binding to both high affinity (K _d = 35 nmol/1) and low affinity (K _d = 8900 nmol/1) _2A-adrenoceptor sites in the proportions 57% and 43%, respectively. The K _d ^Sfor a number of ₂-adrenoceptor subtype selective drugs, measured in competition with [³H]-RX821002 in cerebral cortex and spinal cord, were highly correlated with those obtained in the spleen indicating their _2A-adrenoceptor nature. However, by contrast to the results with the spleen, the guanoxabenz competition curves for the spinal cord and cerebral cortex were monophasic and resolved only into one site fits, the K _d of guanoxabenz being about 4000 nmol/l for both tissues. Drug K _d ^Sfor kidney _2A-adrenoceptors were also determined using [³H]-RX821002. For nearly all drugs tested, the K _d ^Swere highly correlated with those found for the _2A-adrenoceptors in the other rat tissues. However, for guanoxabenz, the data indicated that it competed with [³H]-RX821002 at a single _2A-adrenoceptor site with a K _d of 39 nmol/1. When the rat _2A-adrenoceptor gene RG20 was transiently expressed in COS-7 cells and its ligand binding properties probed using [³H]-RX821002, the drug K _d ^Sobtained were also highly correlated with those found for the _2A-adrenoceptors in the spleen, cerebral cortex, spinal cord and kidney of the rat. For the RG20 encoded receptor, the guanoxabenz competition curves were steep and monophasic and modelled best into one site fits, with the Kd of guanoxabenz being 5200 nmol/1.It is suggested that guanoxabenz can differentiate between two forms of _2A-adrenoceptors in the rat: _2A1 and _2A2. The _2A1-form is present in the spleen and kidney where it shows a high apparent affinity for guanoxabenz. The _2A2-form shows a low apparent affinity for guanoxabenz and is present in the spleen, cerebal cortex and spinal cord. The _2A2-form of the rat ₂-adrenoceptor appears to be encoded by the RG20 gene. The _2A, and _2A2-adrenoceptor forms do not represent high and low affinity receptor forms for agonists because assays included EDTA, Gpp(NH)p and Na⁺, which eliminated the high affinity receptors for agonists.     

Influences of different adenosine receptor subtypes on catalepsy in mice

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.     

乳化剂OP存在下胶束增溶分光光度法测定水中镉

目的：用胶束增溶分光光度法测定水中镉的含量,并比较了乳化剂OP(聚乙二醇辛基苯基醚)和吐温-20(聚氧乙烯山梨醇酐单月桂酸酯)的胶束增溶作用。方法：分别以体积分数为10％OP和体积分数为10％吐温-20为增溶剂,以PAN(1-(2-吡啶偶氮)-2-萘酚)为显色剂,在555nm波长处测定水中镉络合物的吸光度。结果：相同条件下,同浓度的镉络合物用OP的吸光度值是吐温-20的1．6倍,用OP作乳化剂平均回收率为96．5％,平行样品的相对平均偏差为2．57％,标准曲线线性良好,回归系数r=0．999 9,ε=4．6×104L·mol-1·cm-1。结论：乳化剂OP的增溶作用优于吐温-20,此法测定水中痕量镉较好。     

消瘀片对粥样硬化兔血浆ET和血清NO水平的影响

目的　探讨消瘀片抑制血管平滑肌细胞增生的可能作用机理。方法　采用高脂饮食加腹主动脉内膜剥脱术制成兔腹主动脉粥样硬化模型 ,通过放免法和比色法分别测定口服消瘀片 0 .16～ 0 .32 g/ (kg·d) 12周后血浆内皮素 (Endothelin - 1,ET - 1)和血清一氧化氮 (NitricOxide,NO)含量的消长变化。结果　服用消瘀片后的兔血浆ET - 1水平明显降低 ,而血清NO含量明显增加。结论　消瘀片可能是通过降低血浆ET - 1水平 ,增加血清NO含量而抑制动脉粥样硬化血管壁平滑肌细胞的增殖。     

关节灵片镇痛、抗炎作用的实验研究

为探讨关节灵片的镇痛、抗炎作用,用热板法和扭体法观察该药镇痛作用,结果关节灵片为不同剂量灌胃给药对小鼠热致痛和醋酸致痛均有明显抗痛作用,呈现一定的量效关系;关节灵片对二甲苯所致炎性水肿亦有显著的抑制作用。提示关节灵具有较好的镇痛抗炎作用。     

活血化瘀疗法治疗口腔扁平苔癣的疗效观察

目的 探讨活血化阏中成药复方苔癣片对口腔扁平癣（ＯＬＰ）患者红细胞免疫功能的调节作用,为临床用药提供依据。方法 ４０例ＯＬＰ患者随机分为二组,分别给予复方苔癣片、昆明山海棠片进行治疗,采用酵母地检测了治疗前后ＲＢＣ－Ｃ３bＲＲ及ＲＢＣ－ＩＣＰ的变化。结果 治疗２个月后复方苔癣片对ＯＬＰ患者红细胞免疫功能的调节明显优于册海棠片。结论 复方苔癣片是治疗ＯＬＰ的一种有效而副作用轻微的药物,植得在临床上推     

双氯酚酸钠米索前列醇片的抗炎作用研究

双氯酚酸钠米索前列醇片（ＤＳＭＴ）（２０,１０ｍｇ／ｋｇ）连续２ｄ灌胃给药可显著地抑制二甲苯所致鼠耳肿胀（Ｐ〈０．０１,Ｐ〈０．０５）;ＤＳＭＴ（１５,７．５ｍｇ／ｋｇ）灌胃给药均可非常显著抑制角叉菜胶至炎后３ｈ内大鼠足肿胀;ＤＳＭＴ高、低剂量组（１５,７．５ｍｇ／ｋｇ）灌胃给药７ｄdisplay structure     

复方螺旋藻片对正常及实验性糖尿病小鼠血糖的影响

目的：观察复方螺旋藻片（ＦＳＴ）对正常及实验性糖尿病小鼠血糖的影响。方法：用ＦＳＴ１．５ｇ／ｋｇ、３ｇ／ｋｇ分别灌胃给予正常小鼠、链脲佐菌素（ＳＴＺ）性糖尿病小鼠、肾上腺素（Ａｄｒ）性及葡萄性高血糖水鼠,连续１４ｄ后,分别测定各组小鼠空腹血糖。结果：ＦＳＴ１．５ｇ／ｋｇ、３ｇ／ｋｇ能显著降低正常小鼠空腹血糖及ＳＴＺ性糖尿病小鼠高血糖,同时还能拮抗Ａｄｒ与外源性葡萄糖 所致小鼠血糖升高（便ＦＳＴ１．     

Effect of hepatic cirrhosis on the pharmacokinetics of theophylline in rats

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 (t_1/2) 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.