Differences in the effects of beta2- and beta3-adrenoceptor agonists on spontaneous contractions of human nonpregnant myometrium.

Article Details

Citation

Copy to clipboard

Pedzinska-Betiuk A, Modzelewska B, Jozwik M, Jozwik M, Kostrzewska A

Differences in the effects of beta2- and beta3-adrenoceptor agonists on spontaneous contractions of human nonpregnant myometrium.

Ginekol Pol. 2011 Dec;82(12):918-24.

PubMed ID

22384628 [ View in PubMed

]

Abstract

OBJECTIVE: This study aimed to compare the relaxant properties of BRL 37344 with p2-adrenoceptors agonist ritodrine on the contractility of human nonpregnant myometrium. MATERIAL AND METHODS: The activity of myometrial strips mounted in an organ bath was recorded under isometric conditions using force transducers with digital output. Contractility before and after cumulative additions of both uterorelaxants and with preincubation with beta-adrenoceptor antagonists bupranolol, propranolol, and butoxamine were studied. RESULTS: Both BRL 37344 (10(-10)-10(-4) mol/L) and ritodrine (10(-10)-10(-5) mol/L) decreased the area under curve, or AUC, value (log/C50 -6.45 +/- 0.18 and -8.71 +/- 0.35, respectively), and the degree of inhibition of spontaneous contractile activity was similar (< 30%). However BRL 37344 decreased the mean frequency of contractions, whereas ritodrine decreased the mean amplitude of contractions. The inhibition of contractions by BRL 37,344 was partially antagonized by bupranolol and propranolol, but not with butoxamine. The inhibition by ritodrine was counteracted by all these antagonists. CONCLUSIONS: The effects of BRL37344 and ritodrine on human nonpregnant myometrium are quantitatively similar in respect to the inhibition of spontaneous contractility yet are also distinct due to their substantially different influences on contraction parameters. Our data indicate that beta3-adrenoceptor activation is not the sole effect of BRL 37,344 on this tissue.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Ritodrine	Beta adrenergic receptor (Protein Group)	Protein group	Humans	Yes	Agonist Downregulator	Details