The effects of opioids, local anesthetics and adjuvants on isolated pregnant rat uterine muscles.
Methods Find Exp Clin Pharmacol
; 29(4): 273-6, 2007 May.
Article
em En
| MEDLINE
| ID: mdl-17609740
ABSTRACT
Local anaesthetics, opioids and adjuvants are often used for managing labor pain. Some others of these agents are reported to cause alterations on uterine contractility during labor. However, there are controversies and the effects of some others are unknown. In the present study, we aimed to elucidate the effects of opioids such as alfentanyl, meperidine, remifentanyl; local anesthetics such as mepivacaine, ropivacaine, bupivacaine; and adjuvants such as clonidine and midazolam on isolated pregnant rat uterine muscle. Strips of longitudinal uterine smooth muscle obtained from rats pregnant for 18-21 days were suspended in 20 ml organ baths. Isometric tension was continuously measured with an isometric force transducer connected to a computer-based data acquisition system. The effects of cumulative concentrations of alfentanyl, meperidine, remifentanyl, mepivacaine, ropivacaine, bupivacaine, clonidine and midazolam (10(-8) - 10(-4) M, for all) on contractions induced by oxytocin (1 mU/ml) were studied. Alfentanyl (10(-5) M), meperidine (10(-5) M), remifentanyl (10(-4) M), bupivacaine (10(-4) M), ropivacaine (10(-4) M) and midazolam (3 x 10(-5) M) caused significant decreases in contractile responses of uterine strips to oxytocin. Contrastingly, mepivacaine increased (33.1% +/- 7.2%) oxytocin-induced contractions of uterine strips while clonidine exerted no significant effect. The sensitivity of myometrial preparations to tested local anesthetics or opioids did not differ significantly. The findings of the present study demonstrated that some local anesthetics, opioids and adjuvants caused significant and agent-specific alterations on contractility of the pregnant rat myometrium. Therefore, they seemed to have a potential to influence uterine contractility during clinical management of pain during labor. However, further research is needed to extrapolate these finding to clinical practice.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Contração Uterina
/
Analgesia Obstétrica
/
Analgésicos
/
Analgésicos Opioides
/
Anestésicos Locais
/
Miométrio
Limite:
Animals
/
Pregnancy
Idioma:
En
Revista:
Methods Find Exp Clin Pharmacol
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Turquia