Article date: February 1980
By: P.R. BUTCHERS, I.F. SKIDMORE, C.J. VARDEY, A. WHEELDON in Volume 71, Issue 2, pages 663-667
The rank order of potency of six β‐adrenoceptor agonists as inhibitors of the anaphylactic release of histamine from fragments of passively sensitized human lung in vitro was (‐)‐isoprenaline > (‐)‐adrenaline > (±)‐salbutamol > (‐)‐noradrenaline > R0363 > H133/22.
The β‐adrenoceptor antagonists, propranolol, atenolol and H35/25, blocked the response to both (‐)‐isoprenaline and (±)‐salbutamol competively. Each antagonist gave similar pA2 values with both agonists. pA2 values were consistenly at the high end of the range expected for interaction at a β2‐adrenoceptor.
Practolol did not antagonize isoprenaline in a competitive manner but was a competitive antagonist of salbutamol with a pA2 at the high end of the range expected for interaction at a β2‐adrenoceptor.
Data obtained with agonists are consistent with the receptor being of the β2‐subtype. Data obtained with antagonists indicate a consistently higher affinity for the receptor than observed for the β2‐subtype in other tissues but do not suggest a novel β‐adrenoceptor subtype on the mast cell of the human lung.
The rank order of potency of six β‐adrenoceptor agonists as inhibitors of the anaphylactic release of histamine from fragments of passively sensitized human lung in vitro was (‐)‐isoprenaline > (‐)‐adrenaline > (±)‐salbutamol > (‐)‐noradrenaline > R0363 > H133/22.
The β‐adrenoceptor antagonists, propranolol, atenolol and H35/25, blocked the response to both (‐)‐isoprenaline and (±)‐salbutamol competively. Each antagonist gave similar pA2 values with both agonists. pA2 values were consistenly at the high end of the range expected for interaction at a β2‐adrenoceptor.
Practolol did not antagonize isoprenaline in a competitive manner but was a competitive antagonist of salbutamol with a pA2 at the high end of the range expected for interaction at a β2‐adrenoceptor.
Data obtained with agonists are consistent with the receptor being of the β2‐subtype. Data obtained with antagonists indicate a consistently higher affinity for the receptor than observed for the β2‐subtype in other tissues but do not suggest a novel β‐adrenoceptor subtype on the mast cell of the human lung.
DOI: 10.1111/j.1476-5381.1980.tb10987.x
View this article