Biomaterial Database

Neural mechanism underlying tachycardia induced by nonhypotensive a-v shunt. 1979

P D Gupta, and M Singh

The mechanism underlying tachycardia resulting from nonhypotensive arteriovenous shunt (shunt open plus infusion of blood to compensate for the fall in mean arterial pressure resulting from opening of a shunt) was investigated in anesthetized, artificially ventilated dogs. In dogs with intact autonomic innervation, dogs with beta-adrenergic blockage (BB), and dogs with BB plus spinal section at C7 (BBSS), opening of the shunt resulted in tachycardia (P less than 0.01 for all comparisons), which was, however, not significantly different on comparison among groups (P greater than 0.40 for all comparisons). This shows that afferent and efferent sympathetic-mediated reflexes do not play a significant role in this tachycardia response. Additionally, the tachycardia response was significant in dogs with BBSS plus right or left vagotomy, but it was completely abolished in dogs with BBSS plus bilateral vagotomy. This suggests that in dogs with blockade of sympathetic afferent and efferent pathways, tachycardia resulting from nonhypotensive arteriovenous shunt may be due to a cardioacceleratory reflex with its ascending and its descending pathways in each vagus nerve.

UI	MeSH Term	Description	Entries
D007796	Laminectomy	A surgical procedure that entails removing all (laminectomy) or part (laminotomy) of selected vertebral lamina to relieve pressure on the SPINAL CORD and/or SPINAL NERVE ROOTS. Vertebral lamina is the thin flattened posterior wall of vertebral arch that forms the vertebral foramen through which pass the spinal cord and nerve roots.	Laminotomy,Laminectomies,Laminotomies
D008297	Male		Males
D011311	Pressoreceptors	Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls.	Baroreceptors,Receptors, Stretch, Arterial,Receptors, Stretch, Vascular,Stretch Receptors, Arterial,Stretch Receptors, Vascular,Arterial Stretch Receptor,Arterial Stretch Receptors,Baroreceptor,Pressoreceptor,Receptor, Arterial Stretch,Receptor, Vascular Stretch,Receptors, Arterial Stretch,Receptors, Vascular Stretch,Stretch Receptor, Arterial,Stretch Receptor, Vascular,Vascular Stretch Receptor,Vascular Stretch Receptors
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
D012018	Reflex	An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
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
D006321	Heart	The hollow, muscular organ that maintains the circulation of the blood.	Hearts
D006339	Heart Rate	The number of times the HEART VENTRICLES contract per unit of time, usually per minute.	Cardiac Rate,Chronotropism, Cardiac,Heart Rate Control,Heartbeat,Pulse Rate,Cardiac Chronotropy,Cardiac Chronotropism,Cardiac Rates,Chronotropy, Cardiac,Control, Heart Rate,Heart Rates,Heartbeats,Pulse Rates,Rate Control, Heart,Rate, Cardiac,Rate, Heart,Rate, Pulse
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia