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흰쥐 자궁근에서 Na-제거 경축 및 Ba-경축에 관한 연구
A study on the contractures produced by sodium-removal and barium-exposure in rat myometrium

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Authors
이양우장윤석엄융의
Issue Date
1984-03
Publisher
서울대학교 의과대학
Citation
Seoul J Med, Vol.25 No.1, pp. 73-80
Abstract
Mechanical responses to Ka---removal and Ba2+
ι'exposure were investigated in order to elucidate the
-calcium sources for muscle contraction in the longi~
tudinal and circular muscles of rat myometrium. All
experiments were performed in Tris-buffered Tyrode
solution and preparations were usually taken from the
uterus at oestrus stage
The results obtained were as foil 。、:\' 5
1. Oxytocin CO.2mu mL and prostaglandin F ,α
(0. 1μg/rol) induced regular spontaneous contractions
-of the longitudinal and circular muscles of myometrium.
The response of the circular muscle to PG F,a
was more sensitive than that of the longitudinal
muscle.
2. When most of sodium in Tyrode solution was
replaced with Tris, mechanical contracture which has
two components, tonic component 、:\' a s more prominent
in the longitudinal muscle and phasic component in
,circular muscle , were produced. The contractures were
relaxed immediately after readmission of sodium of
normal and Sm1'vl concentrations.
3. Ba2+ C2mM) induced an initial phasic contrac·
ture and a sustained tonic contracture. The tonic
components were dependent upon the external calcium
.eoncentra tions, but in higher concentrations of calcium
(l2mM) were spontaneously relaxed.
4. f\.1n2+, in the concentration of O. GmM, \vhich is
kno、.vn to be calcium-influx antagonist, reduced the
magnitude of Ba2 '-contracture, mainly phasic component
and in 2mM concentration abolished contrac
ture, but not completely.
The above results indicate that there are three
components in mechanical contracture to Na~·-removal
and Ba2c--exposure: the phasic and tonic components
which are highly Ca'• dependent and the third small
tonic component, which is independent of external
Ca• . Most of the phasic and tonic responses seem to
be due to increased calcium influx during membrane
depolarization. And a N"a-Ca exchange mechanism is
considered to contribute to transient phase of the
response to Na-'--remoyal and Na:'-readmission
ISSN
0582-6802
Language
Korean
URI
https://hdl.handle.net/10371/9546
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Appears in Collections:
College of Medicine/School of Medicine (의과대학/대학원)Dept. of Medicine (의학과)The Seoul Journal of MedicineThe Seoul Journal of Medicine Vol. 25 No.1 (1984)
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