The actions of selective β-receptor antagonists on the guinea pig trachea

1 The inhibitory effects were studied of 4 P-adrenoceptor antagonists against renin release induced by isoprenaline (0.5 iimol/l) in rat kidney slices. Additionally the pA2 values of these 4 drugs were measured against isoprenaline in guinea-pig isolated atria and trachea (against fl1-and fl2-adrenoceptors respectively). 2 When employed at a concentration of 2 jimol/l propranolol and atenolol significantly inhibited renin release (P < 0.001 and P < 0.01) whereas practolol and IPS 339 [t-butyl-amino-3 ol-2 propyl) oximino-9 fluorene] had little effect. 3 A positive correlation was shown between the degree of inhibition of renin release and the pA2 of the antagonists at the f3l-adrenoceptors.4 When practolol and IPS 339 were used in equipotent molar concentrations to propranolol for the Pl-adrenoceptors they inhibited renin release.5 The results suggest that the adrenoceptor involved in the renin release induced by isoprenaline in the rat kidney is of the P1-type.

Section: Pa2 Determinationmentioning

confidence: 99%

EVIDENCE FOR THE PARTICIPATION OF β₁‐ADRENOCEPTORS IN ISOPRENALINE‐INDUCED RENIN RELEASE FROM RAT KIDNEY SLICES in vitro

Miesch

Schwartz

1978

“…Isolated trachea (Levy & Wilkenfeld, 1970). The trachea was cut spirally with a sharp scalpel to produce a thin strip of tracheal tissue.…”

Section: Pa2 Valuesmentioning

confidence: 99%

A POTENT NEW β₂‐ADRENOCEPTOR BLOCKING AGENT

Imbs

Miesch

Schwartz

et al. 1977

“…Similar considerations apply to the practolol and methoxamine used in this work. Whilst in the present experiments the slopes of the regression lines for butoxamine and practolol were not markedly different from 1, this is not so in smooth muscle preparations where very low n values (04-048) cobtained for both butoxamine and practolol (Patil, 1968;Levy & Wilkenfeld, 1970), so that precise comparisons between different receptor systems are again not feasible.…”

Section: Discussionmentioning

confidence: 61%

Antagonism by β‐adrenoceptor blocking agents of the antianaphylactic effect of isoprenaline

Assem

Schild

1971

Summary1. f3-Adrenoceptor blocking agents antagonized the inhibitory (antianaphylactic) effect of isoprenaline on antigen-induced histamine release in isolated, passively sensitized, human lung and actively sensitized guinea-pig lung suggesting that the effect is exerted through f3-adrenoceptors. No antagonism was obtained with the human allergic leucocyte preparation. The antianaphylactic effect of isoprenaline was antagonized not only bypropranolol but also by the 'selective' /3-adrenoceptor blocking agents, practolol and butoxamine.3. The classification of /3-adrenoceptors is discussed. Certain similarities between antianaphylactic and lipolytic /8-adrenoceptors are noted.