摘要:

The agent, 6-(N, N-diethylamino)-hexyl-3,4,5-trimethoxybenzoate (TMB-6) which relaxes smooth and skeletal muscle by interfering with intracellular Ca++ availability was tested for its electrophysiological effects on canine cardiac Purkinje fibres and feline papillary muscles. In both tissues the drug causes a decrease in resting membrane potential and action potential amplitude as well as spontaneous rate in Purkinje fibres, and an increase in stimulus needed to reach threshold. The minimum effective dose for both tissues was similar at 7.32 × 10–5M. The drug effects were reversible in both tissues upon removal of the TMB-6. The Ca++-deρendent action potentials of canine cardiac Purkinje fibres were also inhibited by TMB-6 at dose range of 7.32 x 10–5 –24.4 x 10–5M. Because of its electrophysiological effects on threshold, automaticity and ‘slow response’ action potentials and its reversibility, TMB-6 could become a useful antiar

ISSN:0031-7012    

DOI:10.1159/000136585

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

The administration of a diet deficient in thiamin results in elevated hepatic microsomal activity of aniline hydroxylase, ethylmorphine demethylase, NADPH cytochrome c reductase and cytochrome P-450 when compared to similar female rats fed diets supplemented with thiamin. Accompanying these differences in enzyme activity are increased concentrations of microsomal docosahexaenoic acid and arachidonic acid. Binding of aniline to microsomes from rats fed high levels of thiamin is decreased due to a decrease in cytochrome P-450. On the other hand, the binding of ethylmorphine to P-450 is decreased by feeding high levels of thiamin. The daily administration of mestranol enhanced ethylmorphine and aniline metabolism to a greater extent in rats fed thiamin-rich diet than in rats fed thiamin-deficient diet or laboratory chow. This treatment did not increase cytochrome P-450, cytochrome c reductase or microsomal protein nor does it appear to affect the binding of aniline to cytochrome P-450. Ethylmorphine binding is generally decreased by this treatment. Alterations in the Michaelis constants for these reactions were limited to an increase in the KS for aniline in pair-fed animals and in the KS for ethylmorphine in thiamin-deficient rats receiving 1.0 mg mestranol per day.

ISSN:0031-7012    

DOI:10.1159/000136586

出版商:S. Karger AG    

年代:1976

数据来源: Karger

ISSN:0031-7012    

DOI:10.1159/000135774

出版商:S. Karger AG    

年代:1966

数据来源: Karger

摘要:

Totally isolated whole porcine stomachs, perfused extracorporeally with homologous blood, were used for recording gastric electrical and mechanical activity. Hormones were administered into the arterial system of the isolated organ. Pentagastrin, methacholine and electrical stimulation of the vagus nerve induced premature control potentials with uncoupling of the normal, phase-locked, pattern of electrical control activity and also produced electrical response activity and mechanical reaction. When glucagon was infused a progressive decrease of frequency of the cycles of electrical control activity was observed. Glucagon also abolished electrical response activity and mechanical activity, if they were present prior to hormone infusion. When pentagastrin, methacholine or electrical stimulation were applied during the infusion of glucagon, the responses to these stimulants were decreased or absent. The inhibitory action of glucagon was dependent on the duration of infusion of this hormone and lasted for 30–45 min after the infusion was discontinued. During infusion of glucagon the mean gastric arterial perfusion pressure and gastric peripheral vascular resistance were reduce

ISSN:0031-7012    

DOI:10.1159/000136587

出版商:S. Karger AG    

年代:1976

数据来源: Karger

ISSN:0031-7012    

DOI:10.1159/000135775

出版商:S. Karger AG    

年代:1966

数据来源: Karger

ISSN:0031-7012    

DOI:10.1159/000135776

出版商:S. Karger AG    

年代:1966

数据来源: Karger

ISSN:0031-7012    

DOI:10.1159/000135777

出版商:S. Karger AG    

年代:1966

数据来源: Karger

ISSN:0031-7012    

DOI:10.1159/000135778

出版商:S. Karger AG    

年代:1966

数据来源: Karger

摘要:

Cardiac hypertrophy in weanling beagle dogs was obtained by a loose aortic banding with a 10-mm Dacron-Teflon band, positioned 1 cm distal from the aortic valve. 9 months later all animals developed left ventricular hypertrophy without signs of heart failure. Sarcoplasmic reticulum proteins as well as their calcium-exchanging properties were measured in hypertrophic heart and in those from sham-operated control animals. The calcium exchangeable fraction for hypertrophic heart was found to be higher than for controls, while sarcoplasmic reticulum proteins obtained from hypertrophic hearts were lower than those obtained from control animals. It is probable that the increase in the calcium exchangeable fraction could represent a mechanism of compensation in an early stage of the development of the hypertrophic heart whose sarcoplasmic reticulum fraction is not adequately developed.

ISSN:0031-7012    

DOI:10.1159/000136644

出版商:S. Karger AG    

年代:1976

数据来源: Karger

ISSN:0031-7012    

DOI:10.1159/000135779

出版商:S. Karger AG    

年代:1966

数据来源: Karger