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Biomedical subjects

R G Shanks

Publications and source records attributed to R G Shanks.

At least 145 records · Page 8Linked to original sources
PubMed1972

The effect of Kö 1173, a new anticonvulsant agent on experimental cardiac arrhythmias.

1. The effects of the intravenous injection of Kö 1173, a new anticonvulsant drug, phenytoin and procainamide were studied on three types of cardiac arrhythmia in dogs.2. Ventricular ectopic beats produced by intravenous injection of adrenaline in anaesthetized dogs respired with halothane were abolished by Kö 1173, 0.6 +/- 0.1 mg/kg, phenytoin, 1.1 +/- 0.3 mg/kg and procainamide, 4.1 +/- 1.8 mg/kg.3. Ventricular tachycardia was produced in anaesthetized dogs by the intravenous injection of ouabain and the three drugs infused intravenously at 0.2 (mg/kg)/min until sinus rhythm returned. Kö 1173 was effective in 8 out of 9 dogs after a mean dose of 1.3 +/- 0.3 mg/kg; phenytoin in all 3 dogs after 2.7 +/- 0.6 mg/kg and procainamide in the 3 dogs tested after 16.6 +/- 1.3 mg/kg.4. The intravenous injection of Kö 1173, 8.0 mg/kg, greatly reduced the number of ventricular ectopic beats occurring in conscious dogs 18-44 h after ligation of the anterior descending branch of the left coronary artery, with a resultant increase in the number of sinus beats. Phenytoin, 8.0 mg/kg, had a similar effect but procainamide was much less effective.5. These results indicate that Kö 1173 is effective in abolishing experimental cardiac arrhythmias and suggest that its effects should be studied in patients.

Animals↗
PubMed1971

Effects of lignocaine and propranolol on experimental cardiac arrhythmias.

1. The effects of intravenous injection of lignocaine and propranolol were studied in dogs.2. Ventricular ectopic beats produced by intravenous injection of adrenaline in anaesthetized dogs respired with halothane were abolished in four out of six dogs by lignocaine. Propranolol was effective in all three dogs tested.3. Intravenous infusion of lignocaine at (0.2 and 1.0 mg/kg)/min to total doses of 3.0 +/- 1.0 and 2.2 +/- 0.5 mg/kg, respectively, abolished the ventricular tachycardia produced in anaesthetized dogs by ouabain. A similar effect was produced by infusion of propranolol at (0.2 mg/kg)/min to a total dose of 1.9 +/- 0.4 mg/kg. Intravenous injection of single doses of lignocaine (4.0-8.0 mg/kg) also abolished the arrhythmia.4. The frequency of the ventricular ectopic beats occurring in conscious dogs 20-44 h after ligation of the anterior descending branch of the left coronary artery was reduced, with an increase in the number of sinus beats, after intravenous injection of lignocaine (8.0 mg/kg). Larger doses produced excitement. Propranolol (4.0 mg/kg) had a greater effect than the same dose of lignocaine but after 8.0 mg/kg, three of the four dogs died.5. Propranolol was more effective than lignocaine in abolishing the three different types of arrhythmia.6. Dose-response curves showed that lignocaine was more active in abolishing the ouabain induced arrhythmia than the halothane-adrenaline arrhythmia and was least active on the arrhythmia caused by ligation of the coronary artery.

Animals↗
PubMed1971

Comparison of the effects of isoprenaline, orciprenaline, salbutamol and isoetharine on the cardiovascular system of anaesthetized dogs.

1. The intravenous injection of isoprenaline, orciprenaline, salbutamol and isoetharine increased heart rate in anaesthetized dogs. Log dose-response curves obtained with a series of doses of salbutamol and isoetharine were flatter than those for isoprenaline and orciprenaline. The order of activity of the drugs in increasing heart rate was isoprenaline, orciprenaline, and salbutamol=isoetharine.2. The injection into the external iliac artery of isoprenaline, orciprenaline, salbutamol and isoetharine produced dose dependent increases in femoral blood flow. Log dose-response curves for all drugs were parallel. The order of activity of the drugs was isoprenaline, salbutamol=isoetharine and orciprenaline.3. Salbutamol and isoetharine were less active than orciprenaline in increasing heart rate but more active in increasing femoral blood flow.4. These observations indicate that salbutamol and isoetharine have a greater effect on beta(2) than on beta(1)-adrenoceptors in the cardiovascular system.

Amino Alcohols↗