Cg. Acuff et al., ESTRADIOL INDUCES C-TYPE NATRIURETIC PEPTIDE GENE-EXPRESSION IN MOUSEUTERUS, American journal of physiology. Heart and circulatory physiology, 42(6), 1997, pp. 2672-2677
Previous experiments have demonstrated that C-type natriuretic peptide
(CNP) expression in the uterus varies during the estrous cycle with m
aximal expression at proestrus. The present study was designed to dete
rmine whether exogenous steroid hormones regulate uterine CNP expressi
on in ovariectomized mice. Estradiol increased significantly (3-fold)
uterine immunoreactive CNP (irCNP) rapidly and dose dependently in ova
riectomized mice as measured by radioimmunoassay. Other steroids produ
ced either no significant change (testosterone, 1 mg; 2-methoxyestradi
ol, 1 mu g) or weak induction (estriol, 1 mu g) from vehicle controls.
Progesterone (1 mg) significantly attenuated the estrogen-stimulated
irCNP response by 50% when injected 30 min before estrogen (1 mu g) in
estrogen-primed ovariectomized mice. Estrogen-stimulated increases in
uterine CNP transcripts detected by ribonuclease protection analyses
were blocked by actinomycin D (160 mu g) or ICI-164,384 (20 mu g), a s
pecific nuclear estrogen receptor antagonist. These results indicate t
hat a nuclear estrogen receptor is required for estrogen to stimulate
uterine CNP transcription and that progesterone negatively regulates e
strogen-stimulated CNP expression.