摘要:

SUMMARY1. Experimental obstructive jaundice in the Wistar rat causes a significant decrease in heart rate.2. Intravenous administration of cholic acidin vivoelicits a dose‐dependent negative chronotropic effect.3. Atropine or vagotomy significantly reduces, but does not abolish, the negative chronotropic effect of cholic acid.4. Ganglion blockade and decerebration diminishes the negative chronotropic effect of cholic acid, but to a lesser extent than atropine or vagotomy.5. Sympathetic depletion by reserpine slightly potentiates the response to cholic acid.6. The effect of cholic acid injected cranially into the common carotid artery is less than when administered into the jugular vein.7. The haemolysis caused by cholic acid does not appear to be involved in the negative chronotropic effect.8. It is concluded that cholic acid causes both a direct as well as a vagally mediated negative chronotropic effect in the Wistar ra

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1978.tb00645.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

SUMMARY1. Cholic acid has a dose‐dependent negative chronotropic effect on isolated atria ofWistar rats.2. The positive inotropic effect of cholic acid is the result of a negative chronotropic effect and can be eliminated by electrical pacing.3. Cholic acid does not appear to exert its negative chronotropic effect through cholinoceptors and alterations in bath concentrations of calcium and potassium does not influence this effect significantly.4. Cholic acid is a functional antagonist of isoprenaline.5. It is suggested that cholic acid exerts its negative chronotropic effect by forming a monolayer on the surface of the cell membrane, thereby mechanically interfering with membrane functio

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1978.tb00646.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

SUMMARY1. The effects of ajmaline, cocaine, phenytoin, lignocaine, procainamide, propranolol, quinidine and trimetazidine on the contractility and the refractory period of isolated rat papillary muscles were compared.2. At the higher concentrations used, all drugs suppressed the contractile tension of the rat papillary muscles.3. The effects of these drugs on the refractory period were compared at concentrations at which the contractile tension was suppressed by 30% of the control. At this point, lignocaine, procainamide, ajmaline and quinidine prolonged the refractory period more than two‐fold while the effects of propranolol and phenytoin were slight, cocaine and trimetazidine had little or no effec

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1978.tb00647.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

SUMMARY1. The effects of seven dopamine amino acid conjugated derivatives were compared with those of dopamine on sinus rate and contractile force using the isolated, blood‐perfused dog atrium preparation.2. Each of these dopamine derivatives induced dose‐related positive chronotropic and inotropic effects.3. The positive chronotropic and inotropic effects were obtained with the same rank order of potency for each effect with six of the dopamine derivatives. Their rank order and relative potency (dopamine = 1000) were:N‐Ileu‐dopamine (3)>N‐Glu‐Pro‐dopamine (1) =N‐Ala‐Glu‐dopamine (l)>N‐Gly‐Gly‐dopamine (0.3) = N‐γ‐Glu‐dopamine (0.3)>N‐Gly‐Gly‐Leu‐dopamine (0.1)>N‐Gly‐Gly‐Pro‐dopa‐mine (0.01).4. In doses producing equal positive inotropic effects, the positive chronotropic effect ofN‐Gly‐Gly‐Leu‐dopamine was much less than with the other derivatives tested. Its potency compared to dopamine (= 1000) was 0.3 for the inotropic and 0.1 for the chronotropic effect.5. The duration of action of doses of the derivatives producing approximately equal positive inotropic responses was in the orderN‐Ileu‐dopamine =N‐γ‐Glu‐dopamine =N‐Gly‐Pro‐dopamine =N‐Ala‐Glu‐dopa

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1978.tb00648.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

SUMMARY1. Satisfactory surgical anaesthesia in sheep was achieved by i.v. injection of thiopentone sodiumper se(20mg/kg); and also with thiopentone/methoxyfiurane and thiopentone/halothane anaesthetics (2–3% and 1.5–2%, respectively).2. Cardiac arrhythmias were not observed during thiopentone sodium, thiopentone/methoxyfiurane and thiopentone/halothane anaesthesia. However, during thiopentone anaesthesia, one sheep displayed a high degree of sinus tachycardia followed with ventricular tachycardia.3. Pneumograms recorded during thiopentone sodium and thiopentone/methoxyfiurane anaesthesia showed no irregularity, but in thiopentone/halothane anaesthesia, 30% of the sheep developed Cheyne‐Stokes periodic respiration.4. Packed cell volume (PCV) and haemoglobin (Hb) were significantly decreased in thiopentone/methoxyfiurane and thiopentone anaesthetized sheep, but not in animals anaesthetized by thiopentone/halothane.5. White blood cell count (WBC) was significantly decreased only in thiopentone/methoxyfiurane anaesthetized sheep, but was not remarkable in thiopentone and thiopentone/halothane anaesthetized animals.6. A significant lymphocytopenia occurred in thiopentone/methoxyfiurane and in thiopentone/halothane anaesthetized sheep, but not in the thiopentone anaesthetized animals. This was accompanied with an increase in neutrophils.7. Clotting time fell, but the extent and time course was different in thiopentone, thiopentone/methoxyfiurane and thiopentone/halothane anaesthesia.8. From these data, it is suggested that thiopentone sodium, thiopentone/methoxyfiurane and thiopentone/halothane have different effects on different blood parameters during prolonged anaesthesia, and may be clinically signif

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1978.tb00649.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

SUMMARY1. The syndrome of obesity induced by neonatal injection of monosodium glutamate (MSG) has been further studied in mice. In confirmation of previous studies stunting and decreased pituitary and gonadal weights were observed.2. After weaning food intake was consistendy less in MSG‐treated than control mice. Body lipid stores were significantly elevated in MSG‐treated mice by 2 weeks of age and increased progressively up to 4 months.3. Plasma glucose was comparable between MSG‐treated and control mice in the fed state whereas after an overnight fast MSG‐treated mice exhibited relative hypo‐glycaemia.4. Obese MSG‐treated mice did not exhibit resistance to exogenous insulin and disposed of an intravenous glucose load more rapidly than control mice.5. Hyperinsulinaemia was present inconsistently in both fed and fasted mice and in response to administered glucose.6. Neonatal administration of MSG provides a useful additional model for studying the role of the hypothalamus

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1978.tb00650.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

SUMMARY1. The β‐adrenoceptor antagonists atenolol, metoprolol, acebutolol, practolol, propranolol and pindolol have been tested for their ability to reduce isoprenaline‐induced bronchodilation and tachycardia in the anaesthetized dog.2. Atenolol, metoprolol, acebutolol and practolol all possessed a similar degree of cardioselectivity in this animal m

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1978.tb00651.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

SUMMARY1. Intraperitoneal injections of cimetidine into rats markedly reduced gastric acid production. When given at a dose of 50 mg/kg body weight, rate of acid production fell from a mean of 2.73 μmol/min (s.d. = 0.32) to a lowest level of 0.81 (s.d. = 0.28): the difference was highly significant (P<0.005). When given in a dose of 100 mg/kg, the rate of acid production further fell to 0.18 μmmol/min (s.d. = 0.12;P<0.001).2. Treatment with cimetidine in doses of 100 mg/kg 8‐hourly during a 24 h period of restraint prevented the development of acute gastric ulceration in the rat. Pretreatment with cimetidine also protected against the ulcerogenic effects of intragastrically administered bile or lysolecithin.3. The marked sustained reduction of acid production most probably accounts for the protective effect of cimetidine against ulcer production in the rat stom

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1978.tb00652.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

SUMMARY1. A precise and rapid gas chromatographic method for the measurement of plasma sodium valproate concentrations is presented.2. The extraction is a single step procedure, and is reproducible and linear throughout the concentration range encountered.3. Clinical evaluation of the drug is presented in eighteen epileptics on the basis of the percentage of days on which subjects had seizures before and after sodium valproate therapy.4. A tentative therapeutic range for sodium valproate is presented on the basis of plasma levels and therapeutic effect.

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1978.tb00653.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

SUMMARY1. The concentration of methylguanidine and guanidinosuccinic acid has been measured in normal human plasma and discrepancies between various published methods for measuring methylguanidine have been resolved. Previous methods have been modified to allow these guanidines, together with guanidinoacetic acid and creatine, to be measured on the same serum sample.2. Mean values in six normal subjects were as follows: methylguanidine 1.62 μmol/1 (s.d. = 1.3); guanidinosuccinic acid 0.66 μmol/1 (s.d. = 0.22); guanidinoacetic acid 7.06μmol/l (s.d. = 1.29); creatine 80.9μmol/l (s.d. = 37

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1978.tb00654.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY