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Biomedical subjects

G Cheymol

Publications and source records attributed to G Cheymol.

At least 91 records · Page 5Linked to original sources
PubMed1980

[Histamine and serotonin levels in exercise induced bronchospasm in asthmatics (author's transl)].

The authors studied variations in histamine and serotonin levels in whole blood, in ten asthmatics with bronchospasm induced by running. A significant elevation of histamine following exercise was noted both in the asthmatics and in the control group and the difference in histamine levels in the two groups is then significant. However no correlation was found between the level of histamine before or after exercise and bronchospasm or the intensity of the drop in FEV1. This is also true of serotonine. The changes in level of these amines thus seem top play a minimal role in the initiation and intensity of exercise induced bronchospasm in asthmatics.

Adolescent↗
PubMed1979

Effects of the beta-adrenergic blocking agents propranolol and timolol on canine cardiac refractory periods.

The effects of d,1-propranolol and 1-timolol on cardiac refractory periods (RP) were compared in 14 phentobarbital-anesthetized dogs using endocavitary His bundle electrograms and programmable electrical stimulation. Beta-blocking agents were injected at cumulative doses in each dog at 3 day intervals. A control group (6 dogs) received 4 successive saline injections at the same time intervals. RP measurements at a constant drive rate were done before and 10 minutes after each dose of either drug or saline. Propranolol and timolol produced a dose-dependent increase of atrial and atrioventricular nodal refractory periods; dose-response curves were parallel. Depending on the parameter chosen timolol exerted an 8--36 times more potent effect than propranolol. The effects of propanolol and timolol on ventricular effective (VERP) and functional (VFRP) RP were measured in 6 dogs. Both drugs increased VFRP significantly, but saline had the same effect. Only the higher doses of timolol increased VERP significantly. These data confirm that blockade of myocardial beta-adrenergic receptors exerts predominant effects on supraventricular refractoriness and that in anesthetized dogs timolol has more potent beta-blocking properties than does propranolol.

Animals↗
PubMed1979

Study of urinary excretion of butobarbitone in man in relation to the percentage of ideal body weight.

1 Thirty-three patients with no evidence of endocrine disease, hepatic or renal insufficiency or sleep disorders, were classified in groups 1 to 4 in order of increasing of percentage of ideal body weight (IBW) respectively: less than 90% of IBW, 90--120%, 120--180%, and greater than 180% of IBW. After oral administration of 200 mg butobarbitone, concentration of the intact drug was measured by gas liquid chromatographic assay in urine samples collected during 72 h and at three times in blood. 2 A highly significant negative relationship was found between the cumulative excretion of butobarbitone with urine and the logarithm of the percentage of IBW. In contrast for a given weight, excretion of the drug with urine was found to be weakly correlated with the diuresis. 3 The cumulative urinary elimination of butobarbitone was significantly different between the groups studied, except of the difference between the group 2 and 3 of the patients. No significant difference was found between the renal clearances of butobarbitone in the four groups of subjects. 4 We conclude that redistribution of butobarbitone into adipose tissues can explain the obtained results and that obesity modifies the pharmacokinetics of the drug.

Adult↗
PubMed1978

[Merits of the assay of plasma catecholamines in a glucagon test to diagnosis of pheochromocytoma (author's transl)].

In one female patient suffering from an extra-adrenal pheochromocytoma, a stimulation test with glucagon was performed. In spite of the absence of an increase in heart rate and blood pressure, a pronounced increase in plasma catecholamines showed this test to be positive. The authors discuss the reliability criteria of this test, and confirm its good tolerance.

Adrenal Gland Neoplasms↗
PubMed1978

Comparative dromotropic activity of timolol and propranolol in anesthetized dogs.

The comparative dromotropic activity of timolol (TML) and propranolol (PPL) was studied by means of His bundle electrograms in two groups of pentobarbital-anesthetized dogs: group I, 7 non-atropinized dogs; group II, 8 atropinized dogs. beta-Blocking agents were injected in 4 cumulative doses in each dog at 3 days' interval. The effects upon heart rate (HR), and A-V nodal (AH), His--Purkinje (HV) and intraventricular (QS) conduction times were measured. The dromotropic effects of PPL and TML during atrial electrical stimulation and their effects upon chronotropic and dromotropic isoprenaline-induced changes were compared. TML exerted a 9--10 times more potent negative chronotropic effect than PPL and a 4--5 times more potent negative dromotropic effect than PPL on AH conduction time. PPL and TML increased the duration of HV only in higher doses. This effect which was not modified by isoprenaline may be related to their membrane depressant effect. Neither TML, nor PPL nor isoprenaline modified QS duration. TML was 25 times more potent than PPL to antagonize the chronotropic action of isoprenaline and 11--8 times more potent than PPL to antagonize the dromotropic action of isoprenaline upon AH. Parasympathic blockade with atropine did not modify the negative dromotropic activity of PPL and TML but modified their chronotropic effects.

Animals↗
PubMed1977

Pharmacological investigation of cardiovascular and haemodynamic effects of salts of ioxitalamic acid in anaesthetized dogs.

Aqueous solutions of salts of ioxitalamic acid were infected by intravenous, intracarotid, proximal intra-aortic, and intrafemoral route. We observed cardiovascular effects of small magnitude and short duration. They are composed of hypotension (intravenous and intracarotid route), hypotension followed by hypertension (intra-aortic route), changes of LVP, dLVP/dt and contractile strength parallel with those in blood pressure, bradycardia, increased femoral blood flow. Several factors seemed to be involved in the mechanism of these effects: vagal reflex, transient myocardial depression, peripheral vasodilating effect, increased volaemia. By all routes of administration used, the infection of non-iodinated solutions [NaCl, glucose, methylglucamine (MGL) and monoethanolamine (MEA) hydrochloride] of the same osmolarity as ioxitalamate solution, resulted in similar effects.

Animals↗
PubMed1976

Cardiovascular and beta-adrenergic blocking effects of timolol.

The haemodynamic effects of timolol and its inhibiting action on the cardiovascular and bronchial effects of isoproterenol have been studied. Splanchnic nerve activity was recorded. The antiarrhythmic action of timolol was studied on guinea pig isolated atria, using arrhythmias induced by epinephrine, ouabain or coronary ligation in the dog. Timolol is a very potent beta-adrenoceptor blocking agent, without specificity on beta1- or beta2-receptors. No intrinsic beta-stimulating or depressant effects were found. Timolol reduced splanchnic discharges. The antiarrhythmic effect of timolol was limited to epinephrine-induced arrhythmias.

Adrenergic beta-Antagonists↗
PubMed1976

[Comparative study, in the anesthetized dog, of the dromotropic effects of N-propyl ajmaline bitartrate, ajmaline hydrochloride and ajmaline monochloroacetate, by recording of His electrogram].

A-V and intraventricular conduction disturbances induced by 3 different salts of ajmaline: N-propyl ajmaline bitartrate (NPAB), hydrochloride (CHA) and mono chloro-acetate (MCAA), were studied by recording endocavitary His bundle activity in pentobarbital anesthetized dogs. Cumulative dose-response curves were obtained with 3 doses of each compound. The results demonstrate that: a) NPAB exerts a significant depressor effect (9 to 10 times more potent than CHA) on the following three conduction times: auriculo-Hisian, His-Pinkinje and Purkinje-ventricular; b) on His-Purkinje and intra ventricular conduction, MCAA exerts a weaker depressor effect than that of Nab. The lack of parallelism of dose-response curves prevents further comparative quantification; c) on atrio-hisian conduction, MCAA presents a delayed dose-related depressor effect suggesting the presence of an active metabolite. It is concluded that among ajmaline derivatives studied, Nab appears to be the most depressor on A-V and intraventricular conduction in the pentobarbital anesthetized dog.

Acetates↗
PubMed1975

[Cardiovascular and hemodynamic effects of derivatives of metoclopramide].

Two salicylamides, thiapride and sultopride, were found to provoke a dose-related depressor effect in the anesthetized dog. This effect was qualitatively similar to that of procaïnamide and metoclopramide. The hypotensive and negative inotropic effects were not related to the parasympathic system. In fact these compounds are weak autonomic antagonists. They do not exert any anticholinesterase activity. Intra-arterial administration provoked vasodilation.

Animals↗
PubMed1975

[Anti-arrhythmic effects of derivatives of metoclopramide].

The antiarrhythmic effect of Metoclopramide and its analogs, sultopride and thiapride, were studied. In the dog arrhythmias were induced by epinephrine, ouabain and coronary artery ligation. In the guinea-pig the effect of each compound was determined on the ouabain-induced arrhythmias as well as on the refractoriness of the electrically stimulated isolated atria. In the dog sultropide and thiapride were less active than metoclopramide. However, metoclopramide and thiapride depressed auriculo-ventricular conduction. None of these agents exerted a protective antiarrhythmic effect in the guinea-pig. Metoclopramide increased the refractoriness while sultropide and thiapride were almost inactive. Unlike metoclopramide, the two analogs have no local anesthetic activity.

Anesthetics, Local↗