摘要:

The heating procedure of Fleisch and Ehrenpreis is a poorly selective but useful tool for approaching the chemical nature of the pharmacolog ical receptors. According to their stability to a 47°C temperature, for 20 min, receptors may be considered as heat-labile (protein-receptors?) and heat-stable receptors (protein-stable or nonprotein receptors). Both dexamphetamine- and 5-hydroxytryptamine-induced contractions of isolated rat stomach fundal strips werefound to be inhibited by heating. The finding that both amines act on heat-labile receptors should provide a further support for the hypothesis of a common receptor. The mild temperature employed causes some extensive tissue damage, in addition to the denaturation of the heat-labile receptors for dexamphetamine, 5-HT and BaCl2. It alters slightly the cell membrane, as shown by a transient inhibition of the electrically-induced contraction, by inconstantly occurring modifications of the electrical activity, and more, by the net and slowly reversible blockade of the KCl-provoked contraction. The strong inhibition of the BaCl2-induced contraction suggests that barium ions bind with heat-labile membrane structures. Finally, the cholinergic drug furtrethonium acts on heat-stable receptors

ISSN:0031-7012    

DOI:10.1159/000136207

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

The decrease in the kininogen content of the plasma is dependent on the quantity of intravenously injected carrageenin or glass. A dose response correlationis also evident in animals treated with kaolin, although the curve is comparatively flat.

ISSN:0031-7012    

DOI:10.1159/000136208

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

The influence of glucosamine, galactosamine, glucuronic acid and of some derivatives of these compounds on mucopolysaccharide metabolism and on protein metabolism of primary fibroblast monolayer cultures was studied. Glucosamine, glucosamine · HC1, glucosamine · HJ and glucosamine sulfate (in concentrations of 100 µg/ml each) caused a considerable, statistically highly significant increase of the secretion of mucopolysaccharides by the fibroblasts. N-Acetylglucosamine and N-acetylgalactosamine were effective too, though to a lesser degree. Glucuronic acid was without any influence on mucopolysaccharide production. The protein content of the cultures was not affected by the 7 compounds mentioned so far in concentrations of up to 100 µg/ml. Galactosamine and betaineglucuronate induced a certain depression of a mucopolysaccharide production and simultaneously a decrease of the cellular protein cont

ISSN:0031-7012    

DOI:10.1159/000136209

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

In the experiments with adrenalectomized male white rats (180–200 g) treated with DOCA, the following fact is established: a pronounced selective effect of the compound aethimizol (4,5 bis(methylamid)-1-ethylimidazol bicarbonic acid) on the sodium excretion. The data obtained make it possible to consider aethimizol an antagonist of aldosteron

ISSN:0031-7012    

DOI:10.1159/000136210

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

The effects of daily reserpine treatment on thyroxine (T4) metabolism and thyroid gland iodine metabolism were studied in rats. Animals treated with perchlorate were given daily 125I-T4 injections until urinary and fecal excretion of the label stabilized. Reserpine treatment decreased urinary 125iodide excretion but increased radioactivity eliminated in the feces. T4 utilization did not appear to be affected, however. In a second series of experiments rats were given 125iodide in their drinking water to label endogenous iodide stores. Subsequent reserpine treatment increased 125iodine excretion in the feces on day 1; by day 5, fecal radioiodine elimination was depressed, and was blocked completely by the 8th day of drug treatment. Protein-bound iodine was unchanged until day 14, when a slight decrease was observed. At the same time, thyroidal iodide uptake was increased, whereas total (iodide + iodine) in the gland was decreased. This spectrum of changes could be due to an inhibition of iodide incorporation into T4 and other thyroid hormones.

ISSN:0031-7012    

DOI:10.1159/000136211

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

The pharmacodynamic activity of the cysteine molecule was altered by structural modification of functional moieties. Increasing the basicity of the amino group by esterification of the carboxyl group increased potentiating activity. Substitution on either the amino or sulfhydryl moieties adversely affected potentiating activity. Several sulfhydryl-substituted analogs demonstrated noncompetitive antagonism toward bradykinin and acetylcholine responses. An apparent competitive inhibition of eledoisin responses by lower concentrations of several sulfhydryl-substituted analogs can perhaps be attributed to their structural similarity with methioninamide, the C-terminal amino acid in the eledoisin molecule, or to the involvement of spare receptors. The evidence presented by this work suggests that the amino and sulfhydryl groups are essential for the potentiating activity of cysteine.

ISSN:0031-7012    

DOI:10.1159/000136212

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:0031-7012    

DOI:10.1159/000136213

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:0031-7012    

DOI:10.1159/000136214

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:0031-7012    

DOI:10.1159/000135114

出版商:S. Karger AG    

年代:1961

数据来源: Karger

ISSN:0031-7012    

DOI:10.1159/000135115

出版商:S. Karger AG    

年代:1961

数据来源: Karger