Biomaterial Database

Clonidine-induced potentiation of reflex vagal bradycardia in anaesthetized cats. 1982

H E Connor, and G M Drew, and L Finch

The interactions between clonidine and the selective alpha 1- and alpha 2-adrenoceptor antagonists, prazosin and yohimbine, on the angiotensin-induced reflex vagal bradycardia have been investigated in propranolol-treated chloralose-anaesthetized cats. Clonidine (1-10 microgram intracisternally) had little effect on the pressor responses to angiotensin, only slightly increased the peak but markedly increased the duration of the reflex bradycardia. Neither prazosin nor yohimbine (200 microgram intracisternally of either antagonist) had any effect on the reflex bradycardia to angiotensin. Yohimbine greatly diminished the clonidine-induced potentiation of the response, but prazosin was without effect. Clonidine appears to potentiate the vagal reflex bradycardia by stimulating central alpha 2-adrenoceptors.

UI	MeSH Term	Description	Entries
D007267	Injections	Introduction of substances into the body using a needle and syringe.	Injectables,Injectable,Injection
D008297	Male		Males
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
D011942	Receptors, Adrenergic, alpha	One of the two major pharmacological subdivisions of adrenergic receptors that were originally defined by the relative potencies of various adrenergic compounds. The alpha receptors were initially described as excitatory receptors that post-junctionally stimulate SMOOTH MUSCLE contraction. However, further analysis has revealed a more complex picture involving several alpha receptor subtypes and their involvement in feedback regulation.	Adrenergic alpha-Receptor,Adrenergic alpha-Receptors,Receptors, alpha-Adrenergic,alpha-Adrenergic Receptor,alpha-Adrenergic Receptors,Receptor, Adrenergic, alpha,Adrenergic alpha Receptor,Adrenergic alpha Receptors,Receptor, alpha-Adrenergic,Receptors, alpha Adrenergic,alpha Adrenergic Receptor,alpha Adrenergic Receptors,alpha-Receptor, Adrenergic,alpha-Receptors, Adrenergic
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.
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
D002946	Cisterna Magna	One of three principal openings in the SUBARACHNOID SPACE. They are also known as cerebellomedullary cistern, and collectively as cisterns.	Magna, Cisterna
D003000	Clonidine	An imidazoline sympatholytic agent that stimulates ALPHA-2 ADRENERGIC RECEPTORS and central IMIDAZOLINE RECEPTORS. It is commonly used in the management of HYPERTENSION.	Catapres,Catapresan,Catapressan,Chlophazolin,Clofelin,Clofenil,Clonidine Dihydrochloride,Clonidine Hydrochloride,Clonidine Monohydrobromide,Clonidine Monohydrochloride,Clopheline,Dixarit,Gemiton,Hemiton,Isoglaucon,Klofelin,Klofenil,M-5041T,ST-155,Dihydrochloride, Clonidine,Hydrochloride, Clonidine,M 5041T,M5041T,Monohydrobromide, Clonidine,Monohydrochloride, Clonidine,ST 155,ST155
D004347	Drug Interactions	The action of a drug that may affect the activity, metabolism, or toxicity of another drug.	Drug Interaction,Interaction, Drug,Interactions, Drug
D005260	Female		Females