Effects of sex hormones on action potential and contraction of guinea pig papillary muscle.
Zhongguo Yao Li Xue Bao
; 19(3): 248-50, 1998 May.
Article
in En
| MEDLINE
| ID: mdl-10375736
ABSTRACT
AIM:
To study the effects of sex hormones, estradiol (Est), progesterone (Pro) and testosterone (Tes) on the action potential (AP) and contraction of guinea pig papillary muscle.METHODS:
Using conventional glass microelectrode and mechanical recording of myocardial contraction.RESULTS:
Est slowed down the maximal rate of rise of phase 0 (Vmax) of AP at low concentration (1 mumol.L-1). At 10 mumol.L-1 and above, Est also prolonged AP duration (APD50 and APD90), effective refractory period (ERP) and decreased the maximal isometric tension (Pmax) and velocity of tension development (dT/dt) of contraction. Tes (100 mumol.L-1 - 1 mmol.L-1) prolonged APD90 and ERP with decreased Pmax and dT/dt. But Pro (1 mumol.L-1 - 1 mmol.L-1) had no effects on both AP and contraction.CONCLUSION:
Est prolonged AP and depressed contraction of guinea pig papillary muscle.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Papillary Muscles
/
Gonadal Steroid Hormones
/
Myocardial Contraction
Limits:
Animals
Language:
En
Journal:
Zhongguo Yao Li Xue Bao
Year:
1998
Document type:
Article
Affiliation country:
China