Tocopherol inhibits the relaxing effect of terbutaline in the respiratory and reproductive tracts of the rat The role of the oxidative stress index /

AIMS: Reactive oxygen species play a role in the signal transduction of beta-adrenergic receptors. We investigated whether an antioxidant (tocopherol) can reduce the effect of terbutaline in beta-2-adrenergic receptor (beta2-AR)-regulated smooth muscles. MAIN METHODS: Contractility of the tissues fr...

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Bibliographic Details
Main Authors: Hódi Ágnes
Földesi Imre
Ducza Eszter
Hajagos-Tóth Judit
Seres Adrienn
Klukovits Anna
Gáspár Róbert
Format: Article
Published: 2014
Series:LIFE SCIENCES 105 No. 1-2
doi:10.1016/j.lfs.2014.04.023

mtmt:2585036
Online Access:http://publicatio.bibl.u-szeged.hu/9552
Description
Summary:AIMS: Reactive oxygen species play a role in the signal transduction of beta-adrenergic receptors. We investigated whether an antioxidant (tocopherol) can reduce the effect of terbutaline in beta-2-adrenergic receptor (beta2-AR)-regulated smooth muscles. MAIN METHODS: Contractility of the tissues from nonpregnant (trachea) and 22-day-pregnant (myometrium and cervix) rats was investigated in an isolated organ bath. The tracheal and uterine beta2-AR expressions were increased by 17-beta-estradiol valerate (E2) and progesterone (P4), respectively. The accumulation of cyclic-AMP (cAMP), and the total oxidant (TOS) and total antioxidant status (TAS) were also measured. The oxidative stress index (OSI) was defined as the ratio of TOS and TAS. KEY FINDINGS: Terbutaline (10-10-10-5M) decreased the contractions in the nontreated and the P4-pretreated myometria, but tocopherol (10-7M) did not alter these actions. Terbutaline (10-6M) increased the cervical resistance both in the nontreated and in the P4-treated samples, while tocopherol reduced this action only in the P4-treated cervices. Terbutaline (10-9-10-4M) reduced the tracheal tones both in the nontreated and in the E2-treated tissues, while tocopherol reduced these effects. The changes in the intracellular cAMP levels of the tissues were in harmony with the isolated organ results. The OSI was highest in the trachea and lowest in the pregnant myometrium. SIGNIFICANCE: A higher OSI is linked to a higher tocopherol sensitivity of beta-mimetic-induced relaxation. Our results suggest that the antiasthmatic effect of beta-mimetics may worsen, while their tocolytic effect may remain unchanged during parallel tocopherol administration.
Physical Description:48-55
ISSN:0024-3205