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LEAKAGE OF CATECHOLAMINES FROM RABBIT CEREBROSPINAL FLUID FOLLOWING INTRACEREBROVENTRICULAR INJECTION
Author(s) -
Maccarrone C.,
Malta E.,
Raper C.
Publication year - 1983
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.1983.tb00847.x
Subject(s) - cerebrospinal fluid , rabbit (cipher) , cerebrospinal fluid leakage , anesthesia , medicine , computer science , computer security
SUMMARY 1. The intracerebroventricular (i.c.v.) injection of (‐)‐isoprenaline and the selective β 1 ‐adrenoceptor agonist, RO363, elicited reproducible dose‐related increases in heart rate in unanaesthetized and anaesthetized rabbits. (‐)‐Isoprenaline produced vasodepressor effects in unanaesthetized animals, whereas both catecholamines decreased blood pressure in anaesthetized rabbits. 2. Pretreatment with guanethidine sulphate (5 mg/kg i.v.) reduced but did not abolish the tachycardia elicited by i.c.v. RO363, whereas heart rate responses to i.c.v. (‐)‐isoprenaline were unaffected. 3. Pretreatment of anaesthetized rabbits with hexamethonium bromide (10 mg/kg i.v.) did not markedly affect the tachycardia elicited by i.c.v. RO363 and reduced the response to i.c.v. (‐)‐isoprenaline in only one out of five experiments. 4. The results suggest that there is a marked leakage of centrally administered catecholamines into the peripheral circulation and that the rabbit may be unsuited for examining centrally mediated cardiovascular effects of catecholamines.