Biomaterial Database

Coronary vascular responses to nicotine in the anaesthetized dog. 1991

O L Woodman

Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia.

The effect of the intra-coronary (i.c.) injection of nicotine on large coronary artery diameter and coronary blood flow was examined in anaesthetized dogs. In sixteen untreated dogs nicotine (20 micrograms i.c.) had a biphasic effect on arterial pressure (initial increase, 7 +/- 2 mmHg; secondary decrease, -8 +/- 3 mmHg) which was accompanied by small and variable effects on heart rate and an increase in LV dP/dt. Nicotine increased large coronary artery diameter by 5.8 +/- 0.8% but had a biphasic effect on coronary blood flow (initial increase, 41 +/- 7 ml/min; secondary decrease, -10 +/- 2 ml/min). Bilateral vagotomy or muscarinic receptor blockade with atropine (0.1 mg/kg i.v.) did not significantly affect the nicotine-induced changes in coronary artery diameter or coronary blood flow. The additional antagonism of beta-adrenoceptors with propranolol (1 mg/kg i.v.) abolished the effect of nicotine in coronary artery diameter (delta CD = 0.2 +/- 0.2%) and the initial increase in coronary blood flow (delta CBF = 1 +/- 1 ml/min) but enhanced the secondary decrease in flow (delta CBF = -25 +/- 3 ml/min). The nicotine-induced decrease in coronary blood flow observed after muscarinic and beta-adrenoceptor blockade was attenuated by antagonism of alpha 1-adrenoceptors with prazosin (10 micrograms/kg i.c., delta CBF = -15 +/- 3 ml/min) and abolished after additional antagonism of alpha 2-adrenoceptors with idazoxan (50 micrograms/kg i.c., delta CBF = -2 +/- 1 ml/min). These results indicate that in the anaesthetized dog intra-coronary injection of nicotine results in beta-adrenoceptor mediated dilatation of both large and small coronary arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D007269	Injections, Intra-Arterial	Delivery of drugs into an artery.	Injections, Intraarterial,Intra-Arterial Injections,Intraarterial Injections,Injection, Intra-Arterial,Injection, Intraarterial,Injections, Intra Arterial,Intra Arterial Injections,Intra-Arterial Injection,Intraarterial Injection
D007275	Injections, Intravenous	Injections made into a vein for therapeutic or experimental purposes.	Intravenous Injections,Injection, Intravenous,Intravenous Injection
D008297	Male		Males
D009538	Nicotine	Nicotine is highly toxic alkaloid. It is the prototypical agonist at nicotinic cholinergic receptors where it dramatically stimulates neurons and ultimately blocks synaptic transmission. Nicotine is also important medically because of its presence in tobacco smoke.	Nicotine Bitartrate,Nicotine Tartrate
D010275	Parasympathetic Nervous System	The craniosacral division of the autonomic nervous system. The cell bodies of the parasympathetic preganglionic fibers are in brain stem nuclei and in the sacral spinal cord. They synapse in cranial autonomic ganglia or in terminal ganglia near target organs. The parasympathetic nervous system generally acts to conserve resources and restore homeostasis, often with effects reciprocal to the sympathetic nervous system.	Nervous System, Parasympathetic,Nervous Systems, Parasympathetic,Parasympathetic Nervous Systems,System, Parasympathetic Nervous,Systems, Parasympathetic Nervous
D011224	Prazosin	A selective adrenergic alpha-1 antagonist used in the treatment of HEART FAILURE; HYPERTENSION; PHEOCHROMOCYTOMA; RAYNAUD DISEASE; PROSTATIC HYPERTROPHY; and URINARY RETENTION.	Furazosin,Minipress,Pratsiol,Prazosin HCL,Prazosin Hydrochloride,HCL, Prazosin,Hydrochloride, Prazosin
D011433	Propranolol	A widely used non-cardioselective beta-adrenergic antagonist. Propranolol has been used for MYOCARDIAL INFARCTION; ARRHYTHMIA; ANGINA PECTORIS; HYPERTENSION; HYPERTHYROIDISM; MIGRAINE; PHEOCHROMOCYTOMA; and ANXIETY but adverse effects instigate replacement by newer drugs.	Dexpropranolol,AY-20694,Anaprilin,Anapriline,Avlocardyl,Betadren,Dociton,Inderal,Obsidan,Obzidan,Propanolol,Propranolol Hydrochloride,Rexigen,AY 20694,AY20694,Hydrochloride, Propranolol
D003331	Coronary Vessels	The veins and arteries of the HEART.	Coronary Arteries,Sinus Node Artery,Coronary Veins,Arteries, Coronary,Arteries, Sinus Node,Artery, Coronary,Artery, Sinus Node,Coronary Artery,Coronary Vein,Coronary Vessel,Sinus Node Arteries,Vein, Coronary,Veins, Coronary,Vessel, Coronary,Vessels, Coronary
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D005260	Female		Females