摘要:

The catatonogenic action of haloperidol in rats was assessed through different experimental procedures. In the first experiment the animals were injected intraperitoneally with haloperidol, 0.4–4.0 mg/kg, and then divided into two subgroups. The first group was tested for catatonic behavior from 20 min up to 4 h after the injection, while the second was only tested throughout the last 3- to 4-hour period. In the second experiment, animals received, either 0.2 or 0.6 mg haloperidol/kg 3 times at 15-day intervals, and were tested for catatonic behavior from 20 to 240 min after the injection. 15 days after the last drug session, the same animals were injected with distilled water and then tested for catatonia. The results show that retesting drastically influenced the amount of catatonic behavior and that, when under no drug, the rats still displayed catatonia. The data suggest a learning component of this behavio

ISSN:0031-7012    

DOI:10.1159/000137716

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The importance of natural opioids in the central control of blood pressure, heart rate and respiratory function was evaluated with a synthetic analogue of Met-enkephalin, FK 33-824, which is more resistant to enzymatic degradation than the natural opioids. Increasing concentrations (20, 100, 200 and 400 μg/ml), perfused through the 4th cerebral ventricle of the conscious dog, induced a concentration-related depression of respiratory function – as reflected in arterial pCO2 and pO2 – and heart rate. Naloxone (40 μg/ml) was able to reverse respiratory depression whereas bradycardia was naloxone-resistant even after massive (100μg/kg) intravenous doses. Mean arterial blood pressure was not affected in the tested concentration range. Because respiration was reversed by naloxone, it is concluded that respiratory control is regulated by the mu-type opioid receptor. Heart rate, however, may be governed by the delta-type opioid receptor which is less susceptible to na

ISSN:0031-7012    

DOI:10.1159/000137717

出版商:S. Karger AG    

年代:1982

数据来源: Karger

ISSN:0031-7012    

DOI:10.1159/000137771

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Saturable binding of (–)-3H-codeine was found in the guinea pig medulla (KD = 5.6 × 10–7M, Bmax = 1.4 pmol/mg protein), whereas little stereospecific binding was detected (KD = 4.4 × 10–5M). The saturable binding of (–)-3H-codeine was slightly enhanced by Na+ and by Mg++ but not by Li++ and Ca++. The enhancement appears to be due to an increase in the number of receptor sites. (–)-3H-Codeine binding was displaced by (–)- and (+)-codeine, morphine, (–)- and (+)-methadone but not by barbiturates. Naloxone, at a high concentration (1 × 10–5M), inhibits the binding by only 40%. This agrees with our previously published data which shows that the optical isomers of codeine had significant antitussive effects in the cat, these effects not being antagonized by naloxone. A class of opiate antitussive receptors, which are less naloxone-sensitive and less stereoselective than the mu recept

ISSN:0031-7012    

DOI:10.1159/000137718

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The 2-n-propyl- and 2-n-butyl-3-dimethylamino-5,6-methylenedioxyindenes (pr-MDI and bu-MDI, respectively) have been characterized as calcium antagonists with coronary dilating and antiarrhythmic properties. The quaternary 2-n-butyl-3-trimethylamino MDI (Q-bu-MDI) has been demonstrated to possess very potent antiarrhythmic activity in several model systems. In this investigation, the effects of pr-MDI, bu-MDI and Q-bu-MDI on the mechanical and electrical behavior of isolated guinea pig atria were investigated. The tertiary pr- and bu-MDIs caused marked, concentration-dependent decreases in contractile force of stimulated left atria, while the Q-bu-MDI caused only a slight peak reduction in contractile force which was partially reversed at high concentrations. At a concentration of 3 × 10-4M, the pr- and bu-MDIs significantly depressed the frequency-force profile of stimulated left atria, and significantly decreased membrane excitability (as reflected by a significant increase in threshold voltage), while the Q-bu-MDI did not significantly alter either parameter. Spontaneous right atrial rate was only slightly depressed by the three MDI analogues at concentrations of 3 × 10-5 M or less. At higher concentrations, the tertiary pr- and bu-MDIs were much more potent than the quaternary analogue in reducing atrial rate. These results indicate that Q-bu-MDI, the most potent antiarrhythmic analogue in the MDI series, exhibits significantly lesser deleterious effects on cardiac function than the tertiary MDI

ISSN:0031-7012    

DOI:10.1159/000137719

出版商:S. Karger AG    

年代:1982

数据来源: Karger

ISSN:0031-7012    

DOI:10.1159/000137774

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Prostaglandins (PG) E1 and F2α over a dose range of 2.0 pg/ml to 15 μg/ml were tested to determine if they had an effect on the resting potential, action potential amplitude, or action potential duration of isolated superfused canine cardiac Purkinje fibers or feline papillary muscles. The effect of the PGs on spontaneous rate in Purkinje fibers was also tested. PGE1 and PGF2α over a range of 1.0 pg/ml to 20 μg/ml were tested to determine if these compounds had an inotropic effect on feline papillary muscle. The data show that in the range of concentrations tested, PGE1 and PGF2α do not significantly change the electrophysiologic or mechanical response te

ISSN:0031-7012    

DOI:10.1159/000137720

出版商:S. Karger AG    

年代:1982

数据来源: Karger

ISSN:0031-7012    

DOI:10.1159/000137775

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The effects of oral treatment with atenolol and propranolol on blood pressure, heart rate and plasma cyclic adenosine 3’:5’-monophosphate (cAMP) were studied in a group of young borderline hypertensives. Observations were accomplished after a period of recumbent relaxation and also following psychological stress testing. The latter significantly increased blood pressure, heart rate and plasma cAMP. A direct relationship was found between heart rate and plasma cAMP at rest and also following psychological stress. This relationship was lost following drug treatments. Both beta-blockers significantly reduced all measured variables in both conditions. However, plasma cAMP was most affected by proprano

ISSN:0031-7012    

DOI:10.1159/000137721

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Peptide and non-peptide agents were tested for their stimulatory or inhibitory effects on circular strips of guinea pig isolated tracheae. Substance P, eledoisin, physalaemin, neurotensin, angiotensin, histamine and carbachol were found to contract, while noradrena-line, dopamine, bradykinin, nucleotides (AMP, ADP, ATP) and prostaglandins (PGE1; PGE2, PGA2) induced concentration-dependent relaxations of tracheae contracted with substance P or carbachol. Indomethacin (2.8 × 10–6M) significantly potentiated the effect of substance P and blocked that of bradykinin. The contractions to substance P of tissues treated with indomethacin were not modified by atropine, methysergide, diphenhydramine, cimetidine, pro-pranolol, phentolamine, [Leu8]-AT11, [Leu8]-des-Arg9 = octa(4–11). It is concluded that the guinea pig isolated trachea is a pharmacological preparation sensitive to numerous agents and useful for studying structure-activity relationship and the mechanism of cellular action of several peptides, particularly sub

ISSN:0031-7012    

DOI:10.1159/000137722

出版商:S. Karger AG    

年代:1982

数据来源: Karger