Premium
In vitro ACTIVITY OF RO363, A β 1 ‐ADRENOCEPTOR SELECTIVE AGONIST
Author(s) -
IAKOVIDIS D.,
MALTA E.,
McPHERSON G.A.,
RAPER C.
Publication year - 1980
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1980.tb10860.x
Subject(s) - isoprenaline , practolol , agonist , guinea pig , endocrinology , receptor , stimulation , medicine , chemistry , intrinsic activity , biology , pharmacology , propranolol
1 The β‐adrenoceptor stimulant effects of RO363 and (−)‐isoprenaline have been compared in a variety of isolated tissue preparations. 2 RO363 is approximately half as potent as (−)‐isoprenaline in tissues where actions are due to β 1 ‐receptor activation (guinea‐pig atrial and ileal preparations and ventricular strips from the rabbit, rat and guinea‐pig). 3 In uterine and lung strip preparations from the guinea‐pig, where responses are due to β 2 ‐receptor stimulation, RO363 is 100 to 350 times less active than (−)‐isoprenaline and has a low intrinsic activity. 4 In spontaneously contracted tracheal preparations from the guinea‐pig, RO363 is a full agonist and is approximately half as potent as (−)‐isoprenaline. These effects of RO363 are due to the activation of a population of β 1 ‐receptors in the tissue since RO363 and (−)‐isoprenaline have the same relative potencies in trachea, cardiac and ileal preparations. In addition the K B values for practolol are similar in all these preparations when RO363 is used as the agonist. 5 The results show that RO363 is a potent and highly selective β 1 ‐receptor agonist.