Biomaterial Database

Central action of alpha-adrenoceptor agents on the baroreceptor reflex. 1992

D M Ockert, and J Czachurski, and K Dembowsky, and H Seller

I. Physiologisches Institut, Universität Heidelberg, FRG.

In chloralose-anaesthetized cats the effects of intravenous application of the alpha 1- and alpha 2-adrenoceptor agonistic and antagonistic agents methoxamine, prazosin, B-HT 933 and rauwolscine were tested on baroreceptor reflex, sympathetic background activity and blood pressure. Sympathetic activity was recorded from the renal nerve and the efficacy of the central transmission of the baroreceptor reflex was measured by the duration of the complete inhibition of renal nerve activity during electrical stimulation of the left carotid sinus nerve. All baroreceptors were denervated by sectioning both carotid sinus and vagal nerves. The alpha 1-agonist methoxamine increased baroreceptor-induced sympatho-inhibition, sympathetic background activity and blood pressure. The alpha 1-antagonist prazosin had the opposite effects. The alpha 2-agonist B-HT 933 was most effective in augmenting the inhibitory response in sympathetic activity to baroreceptor stimulation; sympathetic background activity and blood pressure were also decreased. At low doses (50 micrograms/kg) the alpha 2-antagonist rauwolscine reduced the baroreceptor sympathetic reflex inhibition and increased sympathetic activity and blood pressure. The effect of B-HT 933 upon the baroreceptor reflex could be completely antagonized by rauwolscine. These findings demonstrate a very effective facilitation of the baroreceptor reflex transmission by stimulation of central alpha 2-adrenoceptors. Through such humoral-neuronal interaction circulating catecholamines are likely to modulate cardiovascular control.

UI	MeSH Term	Description	Entries
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
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.
D002346	Carotid Sinus	The dilated portion of the common carotid artery at its bifurcation into external and internal carotids. It contains baroreceptors which, when stimulated, cause slowing of the heart, vasodilatation, and a fall in blood pressure.	Sinus, Carotid
D002395	Catecholamines	A general class of ortho-dihydroxyphenylalkylamines derived from TYROSINE.	Catecholamine,Sympathin,Sympathins
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D003714	Denervation	The resection or removal of the nerve to an organ or part.	Laser Neurectomy,Neurectomy,Peripheral Neurectomy,Radiofrequency Neurotomy,Denervations,Laser Neurectomies,Neurectomies,Neurectomies, Laser,Neurectomies, Peripheral,Neurectomy, Laser,Neurectomy, Peripheral,Neurotomies, Radiofrequency,Neurotomy, Radiofrequency,Peripheral Neurectomies,Radiofrequency Neurotomies
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D005260	Female		Females
D000316	Adrenergic alpha-Agonists	Drugs that selectively bind to and activate alpha adrenergic receptors.	Adrenergic alpha-Receptor Agonists,alpha-Adrenergic Receptor Agonists,Adrenergic alpha-Agonist,Adrenergic alpha-Receptor Agonist,Receptor Agonists, Adrenergic alpha,Receptor Agonists, alpha-Adrenergic,alpha-Adrenergic Agonist,alpha-Adrenergic Agonists,alpha-Adrenergic Receptor Agonist,Adrenergic alpha Agonist,Adrenergic alpha Agonists,Adrenergic alpha Receptor Agonist,Adrenergic alpha Receptor Agonists,Agonist, Adrenergic alpha-Receptor,Agonist, alpha-Adrenergic,Agonist, alpha-Adrenergic Receptor,Agonists, Adrenergic alpha-Receptor,Agonists, alpha-Adrenergic,Agonists, alpha-Adrenergic Receptor,Receptor Agonist, alpha-Adrenergic,Receptor Agonists, alpha Adrenergic,alpha Adrenergic Agonist,alpha Adrenergic Agonists,alpha Adrenergic Receptor Agonist,alpha Adrenergic Receptor Agonists,alpha-Agonist, Adrenergic,alpha-Agonists, Adrenergic,alpha-Receptor Agonist, Adrenergic,alpha-Receptor Agonists, Adrenergic