ISSN:0901-9928    

DOI:10.1111/j.1600-0773.1987.tb01744.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Abstract:The action of lithium on calcium‐calmodulin‐activated and forskolin‐activated catalytic unit of adenylate cyclase has been studied. The catalytic unit was solubilized from rat brain and separated from the guanine nucleotide binding protein by gel filtration. Calcium‐calmodulin‐stimulated and forskolin‐stimulated catalytic unit activities were inhibited in the presence of 2 mM and 1 mM of lithium, respectively. No inhibitory effect was observed on the basal activity. The inhibitory effect of lithium on the stimulated activities was antagonized by magnesium. Lithium did not influence the interaction of the enzyme substrate (ATP) with the catalytic unit. The present results indicate that lithium interacts directly with the catalytic unit of the adenylate cyclase system. In the neuron, lithium might interfere with a divalent cation site on the cat

ISSN:0901-9928    

DOI:10.1111/j.1600-0773.1987.tb01745.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Abstract:Rat isolated hearts were perfused according to the Langendorff's method. The hearts were prelabelled with3H‐noradrenaline (3H‐NA) and the left coronary artery was occluded during 10 min. The liberation of3H‐NA and the development of ventricular arrhythmias were investigated during ischaemia and the following reperfusion period. In control preparations, reperfusion was followed by ventricular fibrillation and a sudden release of radioactivity in the coronary effluent. Antidepressants such as imipramine, metapramine, mianserin and nomifensine prevented reperfusion arrhythmias in a concentration‐dependent manner and caused bradycardia. Amineptine, however, was ineffective in preventing reperfusion arrhythmias even in a high concentration, this agent did not decrease heart rate. Nevertheless none of the antidepressants changed the rate of liberation of3H‐NA during the ligation and reperfusion periods. A quinidine like action seems the most appropriate explanation for the cardiac effects of these antidepress

ISSN:0901-9928    

DOI:10.1111/j.1600-0773.1987.tb01746.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Abstract:The binding characteristics of3H‐SCH 23390 in rat striatum prepared in potassium phosphate buffer are described. The amount of binding sites labeled by3H‐SCH 23390 decreased monoexponentially when exposed to increasing radiation dose. The molecular weight was determined to 78,000 daltons similar to the molecular mass of3H‐piflutixol binding to D‐1 receptor previously reported, however lower than the molecular mass of dopamine D‐1 agonist binding sites (Gredal&Niel

ISSN:0901-9928    

DOI:10.1111/j.1600-0773.1987.tb01747.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Abstract:Diazepam has previously been shown to affect the acetylcholine synthesizing system in mouse brain. This paper reports studies on the effect of diazepam on muscarinic receptor density and on pharmacological effects of oxotremorine. The receptor density was studied using a new technique that allows such studies to be performedin vivounder physiological conditions. The method is based on the fact that L‐hyoscyamine, the active antipode of atropine, binds specifically to muscarinic receptors in the brain, and can be measured with high sensitivity by gas chromatography‐mass spectrometry. Diazepam was found to modify the binding properties of muscarinic receptors in CNS, thereby decreasing the functional receptor pool. It also prevented tremor induced by the muscarinic agonist oxotremorine. Diazepam could however not prevent the hypothermia induced, but rather accentuated this effect of oxotremorine. It is concluded that diazepam, directly or indirectly, influences the effect of cholinergic stimulators by modulating the size of the muscarinic receptor p

ISSN:0901-9928    

DOI:10.1111/j.1600-0773.1987.tb01748.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Abstract:A previous study (Sund&Lauterbach 1986) in the isolated guinea pig mucosa showed a complex pattern of 1‐naphthol (I) metabolism and metabolite (glucuronide = II and sulphate = III) transport in relation to tissue studied (jejunum and colon) and administration side (lumen versus blood side). In the present paper aspects of I metabolism and II and III transport have been further studied. The experiments involved: I. Omission of inorganic sulphate in the incubation solution at one particular side or at both sides, to see if and how intestinal sulphoconjugation depended on side of sulphate ion entry, and if II and III efflux might be linked to sulphate ion influx. 2. Similar omission experiments with inorganic phosphate, and 3. Incubation in presence of 2,6‐dichloro‐4‐nitrophenol (IV), a drug claimed to be a selective inhibitor of sulphoconjugation. The experiments showed: I. In the jejunum, sulphate ion caused a much stronger stimulation of III formation from the lumen than from the blood side, when I was added at the luminal side. In the colon, however, the sulphate ion was more effective on the blood side than on the lumen side, regardless of side at which I was added. More experiments are needed to clarify if conjugate efflux is affected by sulphate ion omission as well. 2. Omission of inorganic phosphate did neither affect I metabolism nor II and III efflux. 3. IV (present at both sides at once) had complex effects, involving inhibition of II and III synthesis as well as their efflux, and, in part, a change in their normal lumen: blood distribution pattern. Efflux inhibition was the more prominent effect in the jejunum, whereas depression of sulphoconjugation was so in th

ISSN:0901-9928    

DOI:10.1111/j.1600-0773.1987.tb01749.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Abstract:Thein vitrolymphocyte response to mitogen stimulation and thein vitrolymphocyte sensitivity to glucocorticoid were examined in 72 kidney transplanted patients before and after administration of high or low doses of glucocorticoid. Administration of 10 mg of prednisone orally to 10 patients did not significantly change the mitogen responses or the lymphocyte sensitivity to methylprednisolone. Likewise, administration of 100‐120 mg of methylprednisolone, intravenously to 62 patients did not significantly affect the mitogen responses, but, in contrast, the lymphocyte sensitivity to the immunosuppressive effect of methylprednisolone was clearly increased. This effect was highly significant in both cyclosporine A and azathioprine treated patients. These findings suggest that a change of the lymphocyte sensitivity to the immunosuppressive effect of methylprednisolone may occur after a high dose of glucocorticoid, anaesthesia and surgery, although no changes of the immunefunctionsin vitrocan be demonstrated by examining the mitogen response of the lymphocyte cultures. No relationship was found in the present study between the individual lymphocyte sensitivity to glucocorticoid and metabolic clearance rat

ISSN:0901-9928    

DOI:10.1111/j.1600-0773.1987.tb01750.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Abstract:After incubation of miniprisms from rat cerebral cortex or hippocampus with3H‐myo‐inositol, labelling of the phospholipid (“Lipid”) and inositol phosphate (“InsP”) fractions was found. Inositol phospholipid hydrolysis (“PI breakdown”) was stimulated by noradrenaline, 5‐hydroxytryptamine and carbachol. Expressing data as InsP/(Lipid + InsP) was found to be a superior measure of the rate of PI breakdown compared with the more commonly used InsP d.p.m. unit, since the former was found to be independent of the volume of the miniprism aliquot used and the degree of labelling of inositol phospholipids. The PI breakdown responses to noradrenaline, 5‐hydroxytryptamine and particularly carbachol were found to be enhanced by increasing the assay [K+] from 5.88 mM to 18.2 mM. Storage of hippocampal samples at — 70° by the “slow freeze ‐ fast thaw” method of Hardyet al.(1983) resulted in a decreased degree of labelling of the Lipid and InsP fractions and a loss of the PI response to noradrenaline when assayed at a [K+] of 5.88 mM, but a reasonable response was seen in these samples at an assay [K+] of 18.2 mM. The temperature of the Krebs‐Henseleit buffer used in the preparation of the miniprisms was found to be important

ISSN:0901-9928    

DOI:10.1111/j.1600-0773.1987.tb01751.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Abstract:Four aluminium compounds ‐nitrate, chloride, sulphate and bromide‐ were administered orally and intraperitoneally to rats and mice. The LD50 ‐values (14 days) were determined. The majority of deaths occurring during the first four days. The clinical and physical signs appearing after intoxication include among others lethargy, decreased locomotor activity, piloerection, weight loss and perorbital bleeding. After 14 days no alterations in liver and renal functions were detected in the animals which received intraperitoneally the LD50 ‐values of aluminium nitrate as a single dose. Aluminium concentrations were highest in liver and spleen. No histopathological lesions could be observed. To compare the efficacies of nine chelating agents on the toxicity of aluminium in mice, the therapeutic index and the therapeutic effectiveness of each chelating agent have been calculated. Malic, succinic, oxalic and malonic acids showed the best results with malic and succinic acids being the most effective. Deferoxamine mesylate (DFOA), sodium salicylate, L‐cysteine and citric acid were not so effective as antidotes for acute aluminium toxicity. Aurin tricarboxylic acid (ATCA) should not be used due to its high

ISSN:0901-9928    

DOI:10.1111/j.1600-0773.1987.tb01752.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Abstract:Atropine resistant secretion from the submaxillary and sublingual glands was demonstrated upon electrical stimulation of the chorda‐lingual nerve at high frequencies. The flow rate of the protein‐rich saliva was low, and it declined rapidly and markedly upon prolonged stimulation. The results show that one or more substances other than acetylcholine are released by parasympathetic stimulation and that they may be of importance for the regulation of the exocrine functions of the glands. When the continuous mode of electrical stimulation at a low frequency of the nerve was changed to an intermittent mode of stimulation at a high frequency (in the absence of atropine), the secretion of fluid and protein decrea

ISSN:0901-9928    

DOI:10.1111/j.1600-0773.1987.tb01753.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY