Activity of the oxidation products of oleum terebinthinae "Landes" on guinea pig airway smooth muscle in vivo and in vitro.
The oxidation products of Oleum Terebinthinae "Landes" (Ozothin; in the following briefly called Ox. O. T. L.) have been described in many studies as being of benefit in the treatment of disturbed tracheobronchial function in obstructive airways diseases. Previous literature has dealt mainly with the influence of Ox. O. T. L. on the visco-elastic properties of mucus. However, the purpose of the present work was to study the bronchospasmolytic component. Using a standard methodology for the measurement of bronchospasmolytic effects, it could be demonstrated that Ox.O.T.L., given orally or as an aerosol, protected conscious guinea pigs against histamine-induced bronchoconstriction. The potency was lower than that of isoprenaline but was significant and reproducible. These results in vivo are paralleled by effects observed on guinea pig lung strips and tracheal spiral preparations. Ox.O.T.L. relaxed, in a dose-dependent fashion, guinea pig lung strip preparations contracted with histamine. Potency and efficacy was, however, less than that of isoprenaline. Similarly, in guinea pig tracheal spiral preparations, Ox.O.T.L. was less potent than isoprenaline in counteracting carbachol-elevated tone. However, efficacy equalled that of isoprenaline. Ox.O.T.L. was approximately 3 times more potent in the isolated tracheal spiral preparation than in lung strips. The activity of non-oxidised turpentine oil and terpin hydrate against histamine-induced bronchoconstriction in conscious animals and in the isolated organ preparations was substantially lower than that of the oxidation products of O.T.L.
Bermudez
J
J
Beecham Pharmaceuticals Research Division, Medicinal Research Centre, Harlow, Essex, England.
Burgess
M F
MF
Cassidy
F
F
Clarke
G D
GD
D000284:Administration, Oral; D000336:Aerosols; D000818:Animals; D001237:Asphyxia / Q000503:physiopathology; D005260:Female; D006168:Guinea Pigs; D006633:Histamine Antagonists; D066298:In Vitro Techniques; D008168:Lung / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D009822:Oils, Volatile / Q000008:administration & dosage / Q000494:pharmacology*; D012132:Respiratory Muscles / Q000187:drug effects; D012137:Respiratory System / Q000187:drug effects*; D014132:Trachea / Q000187:drug effects
D000336:Aerosols; D006633:Histamine Antagonists; D009822:Oils, Volatile