摘要:

Abstract:α‐And β‐adrenergic inotropic effects have been shown to be qualitatively different. In order to further characterize these differences we compared the mechanical responses to α‐ and β‐adrenoceptor stimulation, respectively, in electrically driven left ventricular papillary muscles from rat heart. The muscles were stimulated by either isoprenaline (β‐adrenoceptor stimulation), phenylephrine in the presence of propranolol (α‐adrenoceptor stimulation) or phenylephrine alone (combined α‐ and β‐adrenoceptor stimulation). Isometric tension (T), rate of rise and decline of tension (first derivative = T′) and rate of transition from tension rise to tension decline (negative part of second derivative = T″) were recorded. These recordings disclosed qualitative differences between the α‐ and β‐inotropic response both in dose‐response and time course experiments. Maximal β‐adrenoceptor stimulation caused a small increase in Tmax(18%), intermediate increases in T′max(45%) and T′min(68%) and a considerable increase in T″min(145%) (“β‐type” effect). Maximal α‐adrenoceptor stimulation increased all qualities by about the same degree (23–24%) (“α‐type” effect). While β‐adrenoceptor stimulation gave a dose‐dependent and pronounced increase in the ratio T″min/T′max(relaxation‐onset index), α‐adrenoceptor stimulation decreased it to subcontrol values and phenylephrine alone gave a small dose‐dependent increase at higher doses. The time course of the α‐adrenoceptor stimulation was characterized by a transient decrease in all qualities followed by an increase which reached maximum at 4–5 min. β‐Adrenoceptor stimulation gave a monophasic response which reached maximum after 1–2 min. Phenylephrine alone gave mainly an “α‐type” effect although T″minincreased significantly more in the absence than in the presence of propranolol and T″min/T′maxshowed a small increase which developed slowly. Thus β‐adrenoceptor stimulation activated relaxation compared to contraction by a higher degree than did α‐adrenoceptor stimulation. This probably reflects different mechanisms of action. While the α‐effect may rely primarily on an i

ISSN:0001-6683    

DOI:10.1111/j.1600-0773.1982.tb00932.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract:Total and differential leucocyte counts, thrombocyte count and blood clotting time of fishes exposed up to 40 days to sewage and some of its individually reproduced chemical factors, fertilisers (urea, potash), chlorinated insecticides (BHC, endrin) and organophosphorus insecticides (monochrotophos, phosphamidon) indicate pathological disturbances involving injury and haemorrhage in tissues.

ISSN:0001-6683    

DOI:10.1111/j.1600-0773.1982.tb00933.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract:l‐Noradrenaline·HCl (l‐NA),d‐noradrenaline·HCl (d‐NA) and dopamine·HCL (DA) were locally applied in the nucleus accumbens of awake rats. When the animals were observed in a dark open field arena it was found that low doses ofl‐NA or DA produced suppression of ambulatory activity followed by an increase in the activity at higher doses.l‐NA was more potent than DA in producing these effects and about 4 times higher doses of DA were required to produce the same effect.d‐NA was not without effects but was less e

ISSN:0001-6683    

DOI:10.1111/j.1600-0773.1982.tb00934.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract:A radioceceptor and a liquid chromatographic assay quantitating serum thioridazine and its active metabolites yielded widely disparate results. The difference between the results of the two assays was relatively random. Contrary to earlier suggestions the radioreceptor assay may not be suitable for the measurement of all neuroleptics particularly when a common reference, such as chlorpromazine, is used.

ISSN:0001-6683    

DOI:10.1111/j.1600-0773.1982.tb00935.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract:Leukotriene (SRS) appears to contribute to the prolonged phase of the tracheal contraction induced by egg albumin, indomethacin and tartrazine as this response was effectively antagonised by FPL 55712. Egg albumin, indomethacin and tartrazine reduced the cAMP level of guinea pig trachea pretreated with adrenergic, cholinergic, histaminergic and 5‐hydroxytryptaminergic antagonists. Egg albumin, but not the other agents, caused a transient increase of the cGMP content. The metabolic and contractile effects were blocked by FPL 55712. It is suggested that the cAMP reduction caused by egg albumin, indomethacin and tartrazine might promote contractions of the tracheal muscl

ISSN:0001-6683    

DOI:10.1111/j.1600-0773.1982.tb00936.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract:Treatment of egg albumin sensitized guinea pigs with repeated concentrations of egg albumin changed the Schultz‐Dale response. The dose‐response curve of egg albumin on the trachea was shifted to the right. Both the amount of SRS‐A and histamine released by antigen exposure from sensitized or desensitized guinea pig lungs were almost similar. Regarding the number of H1‐receptors in an isolated membrane fraction from the lungs of sensitized and desensitized guinea pigs, no significant differences was observed. On the contrary, the receptor‐response to SRS‐A was found to be decreased in desensitized trachea in comparison with sensitized trachea. The treatment of guinea pigs with repeated threshold concentrations of histamine did not change the contractile response neither to histamine nor to egg albumin. The decreased Schultz‐Dale response after repeated egg albumin treatmentin vivomight depend on desensitization of a hypothetical S

ISSN:0001-6683    

DOI:10.1111/j.1600-0773.1982.tb00937.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract:The inducing effects of octachlorostyrene (OCS) and hexachlorobenzene (HCB), chlorinated hydrocarbon contaminants found in fish, on the microsomal cytochrome P‐450 system were studied in rats. Administration of single doses of OCS and HCB at 50mg/kg intraperitoneally and higher led to increases in microsomal protein and cytochrome P‐450 content, cytochrome P‐450 reductase, ethylmorphine N‐demethylase, 4‐nitroanisole O‐demethylase, acetanilide 4‐hydroxylase, but not in benzo(a)pyrene hydroxylase activities. Similar patterns of induction were seen after 14 days repeated intraperitoneal or oral dosing. Sodiumdodecylsulfate polyacrylamide gel electrophoresis of microsomes from OCS and HCB treated rats showed increases in proteins similar to those found after phenobarbital (PB) induction. Under the present experimental conditions OCS and HCB were found to be PB

ISSN:0001-6683    

DOI:10.1111/j.1600-0773.1982.tb00938.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract:Bisacodyl (=BIS) and picosulphate (=PICO) have been given perorally to postoperative gallstone patients, who have undergone biliary tract surgery with the insertion of an indwelling T‐tube. The doses corresponded to 7.7 mg of their common free diphenol desacetylbisacodyl (=DES). The bile was sampled in hourly fractions from the external limb of the T‐tube; these fractions were analysed by a modification of the HPLC method previously used to study biliary excretion in the rat. In the BIS‐patients (n=8), DES in conjugated form occurred in significant concentration already in the first fractions; peak excretion values equivalent to 4–8 μg DES/ml bile were reached in 2–5 hours. Unchanged BIS could not be detected, and the concentration levels of unconjugated DES were insignificant. The PICO‐patients (n=8) on the other hand showed low DES concentrations (conjugated+free≤0.5 μg DES/ml) in all fractions, or low initial concentrations followed by a more or less pronounced rise in the later fractions. These results are, qualitatively, as in the rat. However, the dose fractions excreted in bile (assuming a total hepatic output of 50 ml/hour) seem smaller than those to be expected from rat experiments, at least as far as B

ISSN:0001-6683    

DOI:10.1111/j.1600-0773.1982.tb00939.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract:The degree of myocardial cell necroses in pigs exposed to stress induced by a myorelaxant (succinylcholine) for about 12 min. was investigated. The β‐adrenoceptor blocker propranolol was given in varying doses prior to the induced stress. The degree of necroses in these pigs was evaluated according to a point scale, ranging from 0 to 6 points, and compared with the changes found in untreated controls following stress. The blood levels of noradrenaline and adrenaline were assayed before, during, and immediately after the period of stress. No protective effect of propranolol on the cardiac lesions was found when the drug was administered intravenously in a single dose of either 1 mg or 3 mg per kg. During the period of stress the blood levels of noradrenaline were high, indicating a high degree of activity in the sympatho‐adrenal system. Propranolol in a single dose of 10 mg per kg intravenously reduced the number and size of heart lesions, while the blood levels of the catecholamines were lower under stress than after administration of 1 and 3 mg propranolol. After oral treatment with propranolol, 120 mg three times a day for 6 or 7 days, an almost complete absence of heart cell necrosis after the stress was obtained. The activity of the sympatho‐adrenal system was elevated, as reflected by the high blood levels of catecholamines. The results indicate that stress‐induced heart cell necrosis is mediated via the activity of the sympatho‐adrenal system. The difference between a single and repeated doses of propranolol in protecting the heart suggests a complex ation of the adrenergic β‐rec

ISSN:0001-6683    

DOI:10.1111/j.1600-0773.1982.tb00940.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract:The actylation of sulfanilamide and procainamide in suspensions of isolated rat parenchymal cells was studied in absence and presence of ethanol (33 mM), acetate (0.5–5 mM), citrate (4 mM), pyruvate (4 mM), and L(minus;)carnitine (2 mM). Ethanol treatment enhanced the sulfanilamide acetylation whereas the acetylation of procainamide was considered to be unchanged. Acetate (1–5 mM), citrate, and pyruvate treatment enhanced the acetylation of both sulfanilamide and procainamide. Acetate (4 mM) increased both Kmand Vmaxof both sulfanilamide and procainamide acetylation. Combined treatment with L(minus;)carnitine and either acetate, pyruvate, or citrate enhanced the acetylation rate of sulfanilamide more than acetate, pyruvate, or citrate, respectively alone. In cell suspensions treated with L(minus;)carnitine and acetate or pyruvate, the acetylation kinetics of sulfanilamide changed from zero‐to apparent first‐order. With procainamide as test drug, a further increase of the acetylation rate was found when L(minus;)carnitine was added to citrate or pyruvate. Acetyl‐CoA increased the rate of sulfanilamide acetylation in rat liver homogenates in a dose depende

ISSN:0001-6683    

DOI:10.1111/j.1600-0773.1982.tb00941.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY