F. Pekonen et al., DIFFERENTIAL EXPRESSION OF MESSENGER-RNAS FOR ENDOTHELIN-RELATED PROTEINS IN HUMAN ENDOMETRIUM, MYOMETRIUM AND LEIOMYOMA, Molecular and cellular endocrinology, 103(1-2), 1994, pp. 165-170
The expression of mRNAs encoding endothelin-1 (ET-1) and its receptors
(ET(A)-R and ET(B)-R) as well as the ET degrading enzyme, neutral end
opeptidase 24.11 (NEP), was determined in tissue samples of endometriu
m, myometrium and leiomyoma by using a reverse transcriptase polymeras
e chain reaction (RT-PCR) technique. ET-1 mRNA was detected in all sam
ples studied. The level of ET-1 mRNA was higher in endometrium than in
myometrium (p < 0.01) and Ieiomyoma (p < 0.001). The ET(A)-R mRNA was
more abundant in endometrium than in myometrium (p < 0.001). For ET(B
)-R mRNA there was no difference between these tissues. In contrast to
ET(A)-R mRNA, which was more abundant in leiomyoma than in myometrium
(p < 0.01), the ET(B)-R mRNA was less abundant in leiomyoma (p < 0.01
). The NEP mRNA was detected in all endometrial samples but not in myo
metrium and leiomyoma. Our results show that the expression and relati
ve levels of mRNAs encoding ET-1, ET(A)-R, ET(B)-R, and NEP vary in di
fferent tissue compartments of the human uterus. Since the net biologi
cal action of ET-1 in a particular cell type presumably depends on the
balance between the peptide itself, its receptors and degrading enzym
es, these results suggest different roles for ET-1 action in uterine e
ndometrium, myometrium and leiomyoma. The difference in relative abund
ance of ET(A)-R and ET(B)-R mRNAs between myometrium and leiomyoma sug
gests that an altered ET-R gene expression may be a contributing facto
r in myomal growth.