ABSTRACT
In dogs, treatment with guanabenz, carteolol, and muzolimine for 7 days, reduced the blood pressure responses to bilateral occlusion of the carotid arteries, electric stimulation of central vagus nerve, acetylcholine after atropinization, nicotine, l-noradrenaline, angiotensin II, l-adrenaline, KC1 and asphyxia.
Subject(s)
Blood Pressure/drug effects , Carteolol/pharmacology , Guanabenz/pharmacology , Guanidines/pharmacology , Muzolimine/pharmacology , Propanolamines/pharmacology , Pyrazoles/pharmacology , Anesthesia , Animals , Dogs , MaleABSTRACT
Putrescine produced in anesthetized dogs significant cardiovascular changes at higher doses than other transmitters. The hypotensive response observed after intravenous injection is due to histamine release. Tachycardic effects seem to be due both to release of histamine and to a reflex stimulation of carotid-sinus baroreceptors. The hypotensive and bradycardic effects observed after microinjection of putrescine into the III cerebral ventricle or into the vertebral artery are due to an increase in parasympathetic output.
Subject(s)
Cardiovascular System/drug effects , Putrescine/pharmacology , Animals , Blood Pressure/drug effects , Dogs , Heart Rate/drug effects , Injections, Intra-Arterial , Injections, Intravenous , Injections, Intraventricular , Male , Putrescine/administration & dosage , Respiration/drug effectsABSTRACT
Mexiletine (MXT) is a drug endowed with a marked antiarrhythmic activity which may be included in 1B class of drugs employed in the therapy of arrhythmias. In experimental cardiovascular research, MXT at very high doses induces a decrease in the arterial blood pressure and cardiac performance of dogs. MXT reduces the carotid baroreceptor responses, the fall in blood pressure following pharadic stimulation of the peripheral trunk of the vagus nerve and it also inhibits catecholamine uptake. All these effects may be related to the local anaesthetic activity which MXT possesses and which need careful consideration in the clinical use of the drug.
Subject(s)
Cardiovascular System/drug effects , Mexiletine/toxicity , Propylamines/toxicity , Animals , Anura , Blood Pressure/drug effects , Dogs , Heart Rate/drug effects , In Vitro Techniques , RatsSubject(s)
Antihypertensive Agents/chemical synthesis , Bridged Bicyclo Compounds/chemical synthesis , Bridged-Ring Compounds/chemical synthesis , Acetylcholine/antagonists & inhibitors , Anesthetics, Local/chemical synthesis , Animals , Bridged Bicyclo Compounds/pharmacology , Diamines/chemical synthesis , Diamines/pharmacology , Glycine/analogs & derivatives , Glycine/chemical synthesis , Glycine/pharmacology , Hemodynamics/drug effects , Mice , RatsABSTRACT
The effects of 15(S) 15-methyl-PGF2 alpha were studied on the cardiovascular system of dogs. Intravenous and intravertebral artery administration of 15(S)-methyl-PGF 2 alpha induced arterial hypertensive and respiratory effects more intense and longer lasting than those observed for PGF2 alpha. Intravenous administration of 15(S) 15-methyl-PGF2 alpha induced a decrease of vascular reactivity to 1-norepinephrine and 1-epinephrine and to carotidal occlusion. Infiltration of the carotid sinus walls with 15(S) 15-methyl-PGF2 alpha decreased the baroreceptor reactivity.
Subject(s)
Cardiovascular System/drug effects , Prostaglandins F/administration & dosage , Animals , Blood Pressure/drug effects , Bradycardia/physiopathology , Cardiovascular System/physiopathology , Carotid Sinus/drug effects , Carotid Sinus/physiopathology , Dinoprost , Dogs , Heart Rate/drug effects , Hypertension/physiopathology , Injections, Intra-Arterial , Prostaglandins F/pharmacology , Respiration/drug effects , Tachycardia/physiopathology , Venous Pressure/drug effects , Vertebral ArteryABSTRACT
Hemostatic defects of chronic aggressive hepatitis (CAH), 25 cases, and of liver cirrhosis, 20 cases, were investigated. The following assays were performed: liver function tests, thromboelastogram, prothrombin time (PT), partial thromboplastin time (PTT), factors I, II, V, X, XIII, euglobulin lysis time, fibrinogen degradation products (FDP), platelet count, morphology and agglutinability. High incidence of hemostatic defects was present in both groups. Thromboelastogram, PTT, prothrombin and qualitative platelet abnormalities were most common. On the whole, severity of hemostatic alterations in cirrhosis was more pronounced than that found in CAH, FDPs were increased in more than 50% of the CAH cases and only in a few cirrhotic patients. Bleeding occurred more frequently in cirrhosis (55%) than in CAH (4%) and, within the cirrhotic patients' group, it was associated with a more severe thrombocytopenia.
