[Synthesis of triphenylethylene with aliphatic cyclic moiety and its antagonism on estrogen receptor].

AIM: In order to improve the biological activity and reduce the side effects and toxicity, a series of novel estrogen receptor antagonists were designed. METHODS: The key triphenylethylene intermediates were obtained by the McMurry reaction. The target compounds were prepared by etherification. The binding affinities of the target compounds for the estrogen receptor in rat uterine cytosol were measured by a competitive binding assay and their estrogen agonistic/antagonistic properties were investigated in the 3-day uterine weight assay in the immature rats. RESULTS: Thirty-five new compounds have been synthesized and their geometric configuration were determined by X-ray crystallography and 1HNMR spectral data. CONCLUSION: All of the test compounds showed affinity for the estrogen receptor (IC50 < 10(-6) mol.L-1), especially compound 35 with IC50 1.07 x 10(-8) mol.L-1. Some compounds are antagonists, inhibiting uterus growth; others are agonists, promoting uterus growth. Compounds 14 and 27 are superior antagonists to tamoxifen.

[Effects of tyrosine alone and tyrosine in combination with RU486 on early pregnancy in mice and the mechanism of action].

Treatment with tyrosine at the dosage of 85 mg.kg-1 on day 6-8 of gestation did not have significant effect to terminate early pregnancy in mice. Tyrosine combined with RU486 was shown to have a synergistic effect to terminate early pregnancy. Tyrosine 170 mg.kg-1 on day 6-10 of gestation significantly decreased the concentration of serum progesterone in early pregnant mice. Further study with luteal cells in rats showed that tyrosine 50 micrograms.ml-1 inhibited hCG-induced progesterone production when used alone, and inhibited basal production when used together with (+) PG05. These results suggest that the inhibiting effect of tyrosine on steroidogenesis may contribute to the termination of early pregnancy.

[Effect of (+), (-) and (+/-) gossypol on early pregnancy in rats].

Treatment of rats with (+/-) gossypol 80 mg.kg-1 or (-) gossypol 40 mg.kg-1 on day 6-9 of gestation terminated early pregnancy. However, (+) gossypol at the dosage of 40 mg.kg-1 was found to have no effect on gestation. (-) Gossypol at a concentration of 30 micrograms.ml-1 showed an inhibitory effect on progesterone production and (+) gossypol at 10 micrograms.ml-1 caused an increase of progesterone secretion by luteal cells in vitro. A marked increase of progesterone level in granulosa cells was elicited by hCG. The steroidogenic response of granulosa cells to hCG was inhibited by (+/-) gossypol at 10 and 30 micrograms.ml-1.

[Synthesis of tyrosine-related peptide and their effect on progesterone production].

Twenty peptides containing hydroxy-amino acids have been synthesized manually by stepwise solid-phase procedure. The chloromethyl resin and MBHA resin were used as solid supports. A new reagent of 0.5 mol.L-1 DDSi/1.5 mol.L-1 phenol/DCM was applied for the removal of N alpha-Boc group. TFMSA was the cleaving reagent. After purification by C-18 column; all products were assayed according to amino acid analysis. The bioactivity of synthetic peptides was tested for the effect on progesterone production in vitro. Eight peptides, GlyTyrAlaLys, (SarSer)2Lys and its methyl ester, TyrLys, HisTyr-NH2, ThrProTyrLys-NH2 TyrThrProArgLys and AspHisProThrPheLys showed significant effect on inhibiting hCG-induced progesterone production, and first three of them could also inhibit basal progesterone secretion. However, peptide GlySerTyr exhibited stimulative activity on basal progesterone secretion. So far, no reasonable relationship between structure and bioactivity was found.

[Effect of gonadotropin-releasing peptide (GRP) on LH secretion of mouse pituitary in vitro].

Synthetic GRP and its analogues, GRP-NH2, [Glu7.9.14 Lys6.10] GRP (6-14), [Phe14] GRP (5-14) and [Phe14] GRP, at the concentration of 0.05 mmol.L-1 were shown to have stimulatory effect on LH secretion in cultured mouse pituitary in vitro. The luteotropin releasing activity of GRP and its analogues was estimated to be 115.4, 114.2, 140.0, 162.0 and 179.0% of the control group, respectively. Subcutaneous administration of [Phe14] GRP on days 7-9 and 1-5 of pregnancy and [Phe14] GRP (5-14) on days 2-4 of gestation at dosage of 1 mg.d-1 (each mouse) caused fetal death in 40-60% of mice.

Characterization of absorption and scattering properties of small-volume biological samples using time-resolved spectroscopy.

With time-resolved spectroscopy, we develop an experimental approach by sample substitution to measure the absorption (mu a) and reduced scattering (mu's) coefficients of small-volume biological samples. To investigate the method, small-volume control samples are substituted into a large-size host medium during increases in the absorber (or scatterer) concentration of the host. By characterizing the deviation of the spectra taken with and without the sample, we determine the matching points where the sample and surrounding medium are optically identical. We show that this method can result in correct values of the mu a and mu's for the sample within 6% error if the matching conditions for both the mu a and mu's are fully realized. The results also indicate that this method can give approximate values of the mu a and mu's in a reasonable range if either the mu a or the mu's matching between the two media is realized. This method has been applied to the studies of absorption properties of a human finger and of scattering properties of yeast.

[Effect of dihydroepiandrosterone sulfate on the tension of uterine cervix and its mechanisms].

After i.v. injection of dihydroepiandrosterone sulfate (DHA-S) at 20 or 40 mg/kg to female rats on day 19 of gestation, the tension and hydroxyproline level of uterine cervix were decreased obviously. However, DHA-S at 10 mg/kg showed no effect on the tension of uterine cervix. DHA-S in vitro, at 0.1 mg/kg significantly increased estradiol secretion in the ovaries and placenta of late pregnant rats.

Quantitation of tissue optical characteristics and hemoglobin desaturation by time- and frequency-resolved multi-wavelength spectrophotometry.

Photon migration in highly scattering tissues such as muscle and brain gives optical pathlengths that are dependent upon absorption and scattering parameters, mu a, mu s'. Determination of these parameters gives the correct concentration of principal absorber such as hemoglobin in the red region of the spectrum. Determinations of scatter factor in functioning and pathological tissues are made.

Investigation of the nonlinear aspects of imaging through a highly scattering medium.

The edge-spread function that is expected when imaging a sharp edge in a highly scattering medium using a time-of-flight imaging system has been investigated. Experimental results have been compared with computer simulations. The effect of scattering is to broaden the image of the edge, accompanied by an offset of the midpoint (50% transmission) of the edge. Small random errors in the measurement of the time of flight results in an increase in the offset of the edge position at very short times of flight. The offset in the midpoint of the edge is evidence of the nonlinear nature imaging process, in view of which we conclude that nonlinear algorithms will be necessary to maximize the image information available from measured intensities.

[Synthesis of small peptides containing hydroxy-amino-acid, and its effects on progesterone production].

Eleven peptides containing hydroxy-amino-acid have been synthesized manually by stepwise solid-phase method. Three of them were started on BHA-resin, the others on Merrifield-resin. TFMSA/TFA/p-cresol were used as cleaving reagent in all peptide-resin (1-11) cleavage. Furthermore, HF cleaving procedure was also used parallelly to five of those peptide-resins for contrast. No conspicuous difference in yield was found between TFMSA and HF. The purity of all products was checked by the profiles of analytical reversed phase HPLC (C-18) and the data of amino acid analysis. All synthetic peptides were tested for the effect on progesterone production by rat corpus luteum in vitro. Among them, three peptides, GlyTyr-NH2, LysTyr-NH2 and GlySer Lys-OH, showed significant effect (p less than 0.01) on inhibiting hCG-induced progesterone production.

[Effects of diphenoxylate hydrochloride and dl-15 methyl prostaglandin F2 alpha methyl ester on rat luteal cells].

Diphenoxylate hydrochloride (R1132) at concentrations of 10 and 20 micrograms/ml or dl-15 methyl-PGF2 alpha methyl ester (PG05) at levels of 5 and 10 micrograms/ml was shown to have no effect on progesterone secretion by luteal cells in vitro in the absence of hCG. A marked increase in progesterone level was elicited by hCG as high as 3-8 fold the original value. The steroidogenic response of luteal cells to hCG was inhibited by R1132 and PG05. R1132 at a daily dose of 10 mg/kg or PG05 at a daily dose of 0.1 mg/kg for 5 days showed no obvious effect on ovary progesterone secretion in pseudopregnant rat. However, treatment with R1132 10 mg/kg plus PG05 0.1 mg/kg resulted in a decrease in the progesterone production of ovary in vitro. R1132 and PG05 at doses of 50 mg/kg and 0.5 mg/kg, respectively, exhibited an inhibitory effect on the adenylate cyclase activity.

[Studies on anti-implantation and hormone activity of yuehchukene, an alkaloid isolated from the root of Murraya paniculata].

Oral or subcutaneous administration of yuehchukene to female mice at the dosage of 2 or 4 mg/kg.d on day 1-3 of gestation resulted in 100% anti-implantation effect. However, yuehchukene at 4 mg/kg.d was found to have no anti-implantation effect in hamsters. Allen-Doisy test showed that yuehchukene had obvious estrogenic activity. Treatment of immature mice with yuehchukene at the dosage of 2 or 4 mg/kg.d for 3 days caused an increase of uterine weight. Combined use of yuehchukene with estradiol was shown to have synergistic effect on promoting uterine growth. Experiments showed that the estrogenic activity of yuehchukene was weaker than that of estriol. The affinity of this compound for estrogen receptor was also found to be weaker than that of estriol.

Effect of (-)- and (+)-gossypol on fertility in male rats.

(+)-Gossypol has neither antifertility effect nor toxicity at the dosage of 30 mg/kg orally for 14 days in male rats, but slight damage was found in the germinal epithelium of the testis in animals dosed for 4 weeks. (-)-Gossypol at 30 mg/kg orally for 7 days clearly had an antifertility effect in male rats. It appears that (-)-gossypol is the active stereoisomer of racemic gossypol.

Effects of gossypol acetic acid on rat luteal cells in vitro.

The action of gossypol acetic acid (GAA) on 125I-hCG binding, gonadotropin-stimulated cAMP accumulation and progesterone production was investigated utilizing rat ovaries. Incubation of luteal cells for 3 h with increasing concentration of GAA caused a significant inhibition of gonadotropin-stimulated steroidogenesis. The inhibitory effect of GAA was concentration dependent. GAA at concentrations of 10-30 micrograms/ml reduced cAMP formation in response to hCG. It was shown that the activity of adenylate cyclase of luteal cells was inhibited by 10 micrograms/ml GAA. GAA at a concentration of 30 micrograms/ml was found to have an inhibitory effect on 8Br-cAMP-stimulated progesterone production. GAA did not affect 125I-hCG binding to LH receptor on the luteal cell surface. These results suggest that in luteal cells GAA inhibits steroidogenesis at the step of gonadotropin-stimulated cAMP formation. Adenylate cyclase of luteal cells was inhibited.