• Korean Journal of Animal Reproduction
• /
• v.22 no.1
• /
• pp.61-66
• /
• 1998

In vitro contractile response of the uterus in the pregnant rat to oxytocin increases with advancing gestation. This increase coincides with an increase in uterine oxytocin receptor number. However, in vitro the change in uterine contractile response of the pregnant uterus to oxytocin with advancing gestation is not clear. The purpose of the present study was to find out that the uterine response in vitro to oxytocin changes as delivery a, pp.oaches. Secondly, to determine if the incubation of uterine tissue in vitro altered the uterine oxytocin receptor number and affinity and thus explain the ambiguity between the in vitro and in vitro results. The studies were performed on rats at days 15, 20 and 21 or pregnancy. In vitro the uterine contractile response to oxytocin was sgreater (P<0.05) at day 21 compared to days 15 and 20 (Emax : 724.8　88.9, 130.0　81.5 and 133.4　53.4, respectively). This correlated with a significant increase (P<0.05) in uterine oxytocin receptor number at day 21 (days 21, 15 and 20 : 540　89, 53　24, 89　35 fmoles/mg protein, respectively). However, the kids at days 15, 20 and 21 did not differ (P>0.05). Finally no difference (P>0.05) in oxytocin receptor number or affinity was detected between incubated and non-incubated tissue. The results of these studies suggest that either pre-oxytocin or post-oxytocin receptor factors are important in determining the uterine myometrial responsiveness to oxytocin.

• Korean Journal of Veterinary Research
• /
• v.33 no.3
• /
• pp.381-385
• /
• 1993

수의학 및 농업분야에서 널리 사용되고 있는 살충제인 amitraz의 효과를 척출 돼지 자궁근에서 검토하였다. Amitraz($10^{-8}{\sim}10^{-6}M$)는 발정정지기의 자궁근 수축성을 용량의존적으로 증가시켰다. Amitroaz의 이 효과는 yohimbine($10^{-8}{\sim}10^{-7}M$)에 의해 용량의존적으로 차단되었으나, prazosin($10^{-6}M$)에 의해서는 억제되지 않았다. 또한 $Ca^{2+}$-free Tyrode's solution에서나 verapamil($3{\times}10^{-5}M$)의 전처치에 의해서 amitraz의 수축효과는 완전히 억제되었다. 따라서 amitraz에 의한 발정정지기 돼지 자궁근의 수축은 ${\alpha}_2$-adrenoceptor가 중개하며 이 효과는 주로 $Ca^{2+}$ entry blocker에 감수성이 있는 $Ca^{2+}$ channel을 통한 extracellular $Ca^{2+}$ influx의 증가에 의한 것으로 여겨진다.

• Development and Reproduction
• /
• v.11 no.3
• /
• pp.205-217
• /
• 2007

As an initial step toward better understanding of the molecular mechanism of estrogen-dependent growth in myoma, an optimal primary cell culture condition has been developed and examined by this study. Myoma and myometrium were cultured by two different methods. Culture stability and $E_2$-responsiveness in stable culture were studied. The culture of digested tissue pieces(Method 2) was found to be a stable culture method for the myoma and myometrium showing a favorable response to estrogen. mRNA expression of PR, IGF-1 and IGF-1 receptor genes was enhanced by $E_2$. The gene responses to $E_2$ were higher in myoma compared with myometrium. Moreover, these responses were more expressive in tissues than in the surrounding cells in primary culture of normal myometrium and myoma, implying a vital role of cell communication through the extracellular matrix in maintaining the estrogen-responsiveness. The development of an improved cell culture system for myoma provides an in vitro tool to further investigate the basis of the tumor formation.