Biomedical subjects

S Luo

Publications and source records attributed to S Luo.

At least 109 records · Page 6Linked to original sources

PubMed1998

Prevention of development of dimethylbenz(a)anthracene (DMBA)-induced mammary tumors in the rat by the new nonsteroidal antiestrogen EM-800 (SCH57050).

The effect of EM-800, a new non-steroidal antiestrogen having pure antiestrogenic activity, was studied on chemical carcinogenesis induced by dimethylbenz(a)anthracene (DMBA) as well as on serum lipids and bone mass in the rat. Treatment with EM-800 orally, once daily, for 282 days (9 months), starting 3 days before DMBA administration, decreased the incidence of tumors from 95% in control animals to 60% (p < 0.01), 38% (p < 0.01), and 28% (p < 0.01) at the daily doses of 25 microg, 75 microg, and 250 microg, respectively. The average number of tumors per animal decreased from 4.5 +/- 0.5 tumors in the control group to 0.9 +/- 0.2 (p < 0.01), 0.5 +/-0.2 (p < 0.01), and 0.3 +/- 0.1 (p < 0.01) tumors in the rats treated with the above-indicated doses of the anti-estrogen. In addition, treatment with the increasing doses of EM-800 reduced serum cholesterol levels to 64%, 56%, and 48% of control, while serum triglycerides decreased to 31%, 28%, and 30% of control. Bone mineral content (BMC) and bone mineral density (BMD) of total skeleton, femur, and lumbar spine were not significantly affected following 282 days of treatment with EM-800. However, treatment with EM-800 inhibited the urinary ratio of hydroxyproline to creatinine (HP/Cr) from 14.0 +/- 3.90 micromol/mmol in controls to 7.6 +/-0.8 (p < 0.05), 6.8 +/- 0.8 (p < 0.01), and 6.8 +/- 1.1 (p < 0.01) micromol/mmol, respectively, while the same treatment had no effect on serum total alkaline phosphatase (tALP) activity or urinary calcium and phosphorus excretion. The 25 microg, 75 microg, and 250 microg daily doses of EM-800 inhibited uterine weight by 35% (p < 0.01), 62% (p < 0.01), and 66% (p < 0.01), while vaginal weight was reduced by 8% (p < 0.05), 30% (p < 0.01), and 38% (p < 0.01), respectively. In agreement with the 27% increment (p < 0.05) in ovarian weight at the highest anti-estrogen dose used, serum androstenedione (p < 0.05), androst-5-ene-3beta,17beta-diol (p < 0.01), testosterone (p < 0.05), and estradiol (p < 0.01) levels were increased. The present data show that EM-800 prevents the development of DMBA-induced mammary tumors while simultaneously inhibiting uterine and vaginal weight, reducing serum cholesterol and triglyceride levels, and having no adverse effect on bone mass following 9 months of treatment in the rat.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1998

Plasma thrombopoietin (TPO) levels and expression of TPO receptor on platelets in patients with myelodysplastic syndromes.

Data on endogenous thrombopoietin (TPO) levels and their regulation in myelodysplastic syndromes (MDS) are sparse. We examined the plasma TPO level of 85 MDS patients by a sensitive enzyme immunoassay and the platelet expression of TPO receptor (TPO-R) protein, which metabolizes endogenous TPO, in 19 MDS patients with an equilibrium binding assay using 125I-TPO. The MDS patients had higher plasma TPO levels (7.0 +/- 9.3 fmol/ml) than 52 normal subjects (P < 0.0001). Refractory anaemia (RA) patients (n = 39) had higher plasma TPO levels than patients (n = 28) with RA with excess blasts (RAEB) or RAEB in transformation (RAEB-t) (P = 0.0002), irrespective of similar platelet counts in these groups. The plasma TPO level correlated inversely with the platelet count in RA patients (P = 0.0027) but not in RAEB and RAEB-t patients (P = 0.7865). These data suggest that the physiological pathway for TPO production and metabolism is conserved, at least partially, in RA, but deranged in RAEB/RAEB-t. The number of TPO-R per platelet was significantly smaller in 19 MDS patients (17.5 +/- 13.3) than in normals (P = 0.0014), but similar between RA patients and patients with RAEB and RAEB-t. Further, the bone marrow megakaryocyte count, determined in 31 MDS patients, was quite similar between RA patients and patients with RAEB or RAEB-t. Thus, in addition to thrombocytopenia, a reduced platelet TPO-R number may contribute to elevated plasma TPO levels in MDS, and a regulatory pathway for circulating TPO other than platelet TPO-R and marrow megakaryocytes, such as blasts expressing TPO-R, may operate in RAEB/RAEB-t.

Blood Platelets↗

PubMed1998

Bromocriptine reduces obesity, glucose intolerance and extracellular monoamine metabolite levels in the ventromedial hypothalamus of Syrian hamsters.

We examined whether reductions in body fat stores and insulin resistance in Syrian hamsters induced by bromocriptine are associated with reductions in daily norepinephrine (NE) and serotonin activities as indicated by their extracellular metabolite levels in the ventromedial hypothalamus (VMH). High levels of these monoamines within the VMH have been suspected to induce obesity and insulin resistance. Microdialysate samples from the VMH of freely moving obese male hamsters (BW: 208 +/- 5 g) were collected hourly over a 25-hour period before bromocriptine treatment, during the first day of and after 2 weeks of bromocriptine treatment (800 microg/animal daily, i.p.), and body composition and glucose tolerance analyses were conducted before and after 2 weeks of treatments. The microdialysate samples were analyzed by HPLC for metabolites of serotonin: 5-hydroxy-indoleacetic acid (5-HIAA), NE: 3-methoxy-4-hydroxy-phenylglycol (MHPG), and dopamine: homovanillic acid (HVA). Bromocriptine treatment for 14 days significantly reduced body fat by 60% and areas under the glucose and insulin curves during a glucose tolerance test by 50 and 46%, respectively. Concurrently, extracellular VMH contents of 5-HIAA, MHPG, and HVA were reduced by 50, 29 and 66%, respectively (p < 0.05). Similarly, VMH 5-HIAA and MHPG contents were 48 and 44% less, respectively (p < 0.05), in naturally glucose-tolerant hamsters compared with naturally glucose-intolerant hamsters. Bromocriptine induced reductions of body fat, and improvements in glucose intolerance may result in part from its ability to decrease serotonin and NE activities in the VMH.

Adipose Tissue↗

PubMed1998

Effect of twenty-four-week treatment with the antiestrogen EM-800 on estrogen-sensitive parameters in intact and ovariectomized mice.

Treatment with the antiestrogen EM-800, at the daily oral dose of 3 microg, 10 microg, 30 microg, or 100 microg for 24 weeks, caused a marked inhibition of uterine and vaginal weight in both intact and ovariectomized mice. Maximal 64% and 41% inhibitions of uterine weight were achieved in intact and ovariectomized animals, respectively. Similar inhibitory effects of EM-800 were observed on vaginal weight with maximal inhibitions of 71% and 35%, in intact and ovariectomized animals, respectively. The pure antiestrogenic activity of EM-800 on the hypothalamo-pituitary-ovarian axis is illustrated by the 76-91% increases in ovarian weight observed in intact animals treated with the 10-100 microg doses of the antiestrogen. Serum 17beta-estradiol was 93% increased at the 100 microg daily dose of EM-800, whereas serum androstenedione, testosterone, and dihydrotestosterone were 141-713% increased over control at the same dose of the antiestrogen. Serum LH was increased by treatment with EM-800 in intact animals, whereas no effect was observed on the elevated gonadotropin levels in ovariectomized animals. At all doses used in intact animals, the antiestrogen caused a complete disappearance of the glandular elements of the mammary gland, the atrophy being comparable with that observed in ovariectomized mice. The mammary gland of EM-800-treated animals was exclusively composed of an atrophied ductal system lined by atrophied epithelial cells with an absence of lobulo-glandular elements. No effect of the compound was observed on the histology of the mammary gland in ovariectomized animals, thus showing the pure antiestrogenic effect of EM-800 on the mammary gland, as shown also for the uterus, vagina, and hypothalamo-pituitary axis. At histopathology, all doses of EM-800 in intact animals led to a moderate to severe uterine and vaginal atrophy. The uterine atrophy affected both the myometrium and the endometrium. Interestingly, the uterine atrophy achieved in intact animals treated with EM-800 was greater than that observed after ovariectomy alone, thus clearly demonstrating the pure antiestrogenic activity of EM-800. The present data show the highly potent and pure antiestrogenic activity of EM-800 on all parameters measured after 6 months of treatment in both intact and ovariectomized mice, a maximal effect being reached at the daily 10 microg dose of the antiestrogen in intact animals.

Androstenedione↗

PubMed1998

[The risk of lung cancer and mesothelioma in farmers exposed to crocidolite in environment].

To assess the risk of lung cancer and mesothelioma after environmental exposure to crocidolite for 20-30 years, a retrospective cohort study was carried out in farmers who had been exposed to crocidolite in environment. 1610 subjects were followed up for 9 years (Jan. 1, 1987 Dec. 31, 1995). The control group consisted of 7646 farmers who resided in the noncrocidolite pollution rural area in the same province. The results showed that the annual mortality rate was 43.75 per 100,000 population for lung cancer, and 36.46 per 100,000 for mesothelioma. Significantly high risks of lung cancer (RR 5.67) and mesothelioma (RR 182.3) were noted. These results demonstrate a strong causal association between lung cancer, mesothelioma and exposure to crocidolite.

Adult↗

PubMed1998

[Effect of Jianpi Yiqi recipe on the heat shock proteins in rats with acute injury of gastric mucosa].

OBJECTIVE: To investigate the mechanism of Jianpi Yiqi Recipe (JPYQR) in inhibition of gastric mucosa injury. METHODS: A rat model of acute injury of gastric mucosa was established by binding and immersing in water. Ulcer index (UI) was measured, change of heat shock protein (HSP70) in plasma and gastric tissue was examined, and the gastric HSPs was studied immunohistochemically. RESULTS: The UI in rats pretreated with JPYQR or Lizhudele was lower than that of model group (P < 0.001), and UI of JPYQR group was lower than that of Lizhudele group (P < 0.01). On the other hand, the HSP70 level in the two pretreated groups were significantly higher than that of the model group (P < 0.05), and the plasma HSP70 level of JPYQR group was higher than that of Lizhudele group (P < 0.05). The difference of gastric HSP70 level between the two pretreated groups was insignificant (P > 0.05). Immunohistochemical study revealed a high level expression of HSP70 and HSP60 by glands and the level of the expression in model group was the highest, followed by those in Lizhudele group and JPYQR group. CONCLUSION: JPYQR could enhance the expression of HSPs in rats, and so as to prevent the gastric mucosa from injury. HSPs might involve in the defending mechanism of gastric mucosa.

Animals↗

PubMed1998

[Activation of insulin-like growth factor 1 gene expression in growing rat condyle by functional mandibular protrusion].

OBJECTIVE: We studied the changes of the IGF-1 mRNA expression in condylar cartilage to elucidate the biomolecular mechanism of mandibular advancement. METHODS: Sixty 5-week-old male rats were randomly divided into experimental and control groups. The mimic functional appliances were used in experimental group. The rats were sacrificed after 1, 3, 7, 14, 21 and 28 days to study the expression of IGF-1 mRNA by in situ hybridization. RESULTS: The results showed IGF-1 mRNA expression in the condylar cartilage. The transitional and maturational layers had the most abundant IGF-1 mRNA, and the IGF-1 mRNA abundance of germinal layer is higher than that of synovial and fibrous layers. Functional mandibular protrusion activated the IGF-1 mRNA expression and it began to increase after 3 days of the experiment, and the changes were most significant in 7-14 days. CONCLUSION: This suggested that the condylar cartilage growth and remolding after functional protrusion might be caused by IGF-1 gene expression activation.

Animals↗

PubMed1998

[An experimental study on the changes of estrogen receptor in the condylar cartilages with DCC method in rats after functional mandibular protrusion].

OBJECTIVE: The purpose of the study was to evaluate the estrogen receptors (ER) in the condylar cartilages in relation to the hyperplasia, hypertrophy and functional adaptive remodelling after functional mandibular protrusion. METHODS: Dextran-coated charcoal (DCC) method was performed to quantitively detect the level of ER. Fifty female rats of 4-week-old were selected and simulated functional appliances were used to guide their mandibles. The rats were sacrificed after 3 days, 1 week, 2 week, 3 week and 4 week. RESULTS: The results showed ER do exist in the condylar cartilages of the rats, with the highest levels during their actively proliferative period and the amount of ER was increased significantly after functional mandibular protrusion. CONCLUSION: It is suggested that ER has a close relationship with the hyperplasia, hypertrophy of the condylar cartilages and plays a very important role in the adaptive remodelling mechanism after functional mandibular protrusion.

Animals↗

PubMed1998

[Determination of levofloxacin in plasma and cerebrospinal fluid with HPLC and its pharmacokinetics in patients undergoing neurosurgical operations].

A RP-HPLC method was developed to determine the concentrations of levofloxacin in plasma and cerebrospinal fluid and its pharmacokinetics were studied in patients undergoing neurosurgical operations. C18H37 column was eluted with the mobile phase consisting of 10 mmol.L-1 KH2PO4-10 mmol.L-1(C4H9)4Br-CH3CN(45:45:10, pH 3.0) and the utraviolet absorbance was monitored at 295 nm. Ciprofloxacin was used as internal standard. The mean recoveries were 74.76% in plasma and 82.43% in cerebrospinal fluid, with the lowest detectable limits of 10 micrograms.L-1 and 6 micrograms.L-1, respectively. The RSD for the intra-day and inter-day were all less than 5%. A single oral administration of 300 mg levofloxacin tablet was given to 10 patients undergoing neurosurgical operations. The pharmacokinetic parameters in blood and in cerebrospinal fluid could be described by one compartment open model. The pharmacokinetic parameters were: blood Ke 0.12 +/- 0.04 h-1, T1/2 6.05 +/- 1.68 h, Tmax 1.05 +/- 0.29 h, Cmax 3.67 +/- 0.42 mg.L-1, AUC 33.43 +/- 7.32 mg.h.L-1, CLs 9.46 +/- 2.53 L.h-1, Vd 77.49 +/- 7.39 L; cerebrospinal fluid Ke 0.11 +/- 0.04 h-1, T1/2 6.95 +/- 1.88 h, Tmax 3.56 +/- 1.24 h, Cmax 1.68 +/- 0.25 mg.L-1, AUC 23.70 +/- 5.62 mg.h.L-1, CLs 13.70 +/- 5.11 L.h-1, Vd 126.61 +/- 13.20 L.

Adult↗

PubMed1998

[In situ hybridization with digoxigenin-labelling oligonucleotide: an practical approach to skeletal tissues].

The purpose of this study was to investigate the in situ hybridization technique of paraffin-embedded skeletal tissues by non-radioactive labelling oligonucleotide, Five six-week-old male SD rats were selected and the proximal epiphyseal growth plates of bilateral tibiae were removed to be decalcified in 0.5 mol/L EDTA. The tissues were embedded by paraffin and the sections were treated and hybridized with RNase-free reagents. Control groups were set to testified the sensitivity and the specificity of the experiment. The results showed that this method preserved the integrate structures and effectively detected the mRNA of the tissues. These indicated that it was an efficient and practical approach to the biomolecular research of skeletal tissue.

Animals↗

PubMed1998

[DNA vaccine of Plasmodium falciparum: immune response of BALB/c mice induced by injection of the recombinant plasmid DNA].

AIM: To observe the level of immune responses of BALB/c mice induced by direct injection of the recombinant plasmid DNA and to provide evidence for the application of DNA vaccine of Plasmodium falciparum (P. f.) in animals and humans. METHODS: The recombinant plasmid pcDNA3-Pf8 encoding the hybrid antigens of PfCMR-MSP1(19) was constructed. The presence of Pf8 plasmid was detected in the muscle, liver, kidney, heart, spleen and lung by PCR. ELISA, T lymphocyte transformation test, inhibitory assay of the growth and development of P. f. in vitro were used to determine the level of humoral and Th-cell responses. RESULTS: pcDNA3-Pf8 was amplified by PCR technique in the different tissues from BALB/c mice which were injected with pcDNA3-Pf8. The immune serum was specifically recognized by the soluble antigens of P. falciparum (titer: 1:2,560 by ELISA). The specific proliferative response of spleen T cells from immunized mice was remarkably higher than that of control group, the transformation rate being up to 32.82 +/- 3.64%. The immune serum could also inhibit the growth and development of the erythrocytic stages of P. falciparum in vitro. CONCLUSION: Direct injection with the recombinant plasmid pcDNA3-Pf8 specifically elicits BALB/c mice to generate humoral and cell-mediated immune responses, the resulting immune serum being inhibitory to the growth and development of P. f. in vitro.

Animals↗

PubMed1998

[Cloning and sequencing of the gene coding the sexual stage antigen Pfs48/45 of Plasmodium falciparum].

AIM: To express the antigen Pfs48/45 in vitro and provide an antigen for the development of the transmission-blocking vaccine. METHODS: According to the published nucleotide sequence of Pfs48/45 of Plasmodium falciparum isolate NF54, a pair of oligonucleotides was designed and used as primers(P1, P2). The gene encoding the gametocyte/gamete-specific membrane protein Pfs48/45 of P. falciparum isolate FCC1/HN has been amplified by using polymerase chain reaction (PCR) technique. The PCR product was purified and directly sequenced by the dideoxynucleotide terminator method with 5'-end primer P1. At the same time, the purified PCR product was digested with BamHI and EcoRI and cloned into the plasmid pcDNA3, then the recombinant clones were transformed into E. coli strain TG1. The recombinant plasmid pcDNA3-Pfs48/45 was screened and identified by PCR amplification and restriction analysis. RESULTS: 1. The gene fragment Pfs48/45 was specifically amplified from the genomic DNA of Plasmodium falciparum isolate FCC1/HN; 2. The sequence demonstrated that the that the 5'-end nucleotide and predicted aminoacid sequence of Pfs48/45 from FCC1/HN isolate was basically identical with that from NF54 isolate. We found that the sequence of the Pfs48/45 gene from the isolate FCC1/HN differs from the published sequence(isolate NF54) only at positions 307 and 372(T-->C). The substitution of T-->C at the position of 372 generates a new restriction site Taq I. The PCR product digested by Taq I generates DNA fragment of 984 bp and 379 bp, suggesting that the PCR product is the gene encoding the transmission blocking antigen Pfs48/45; 3. The gene fragment of Pfs48/45 was directly inserted into the BamHI and EcoRI site of plasmid pcDNA3. CONCLUSION: The nucleotide sequence of Pfs48/45 of Plasmodium falciparum isolate FCC1/HN from south China was similar to that of isolate NF54. The recombinant plasmid pcDNA3-Pfs48/45 was successfully constructed, providing a means to evaluate the role and biological function of this sexual-stage-specific protein of Pfs48/45.

Amino Acid Sequence↗

PubMed1998

[Effects of pregnancy on orthodontic tooth movements: effects of progesterone on orthodontic tooth movements in pregnant rats].

This study evaluated the periodontal responses and progesterone changes to orthodontic tooth movements in pregnant rats. Adult female Sprague-Dawley rats were separated into two groups: non-pregnant and pregnant. All rats were treated with fixed orthodontic appliances that moved the upper incisors in a distal direction during 10 days. At the end of the experiment, the periodontal tissues were examined histologically and immunohistochemically (ABC method). The results showed that in the histological examination of the tension sides of the upper incisors, the bone formation was more obvious in the pregnant group than that in the non-pregnant group. In the immunohistochemical staining, the osteoblasts were positive-stained cells and they exhibited deeper stain and higher percentage in the pregnant group. In a conclusion, the progesterone influences the periodontal reconstruction on orthodontic tooth movements in pregnant rats and may be helpful in alveolar bone formation, which suggests that orthodontic treatments in pregnant patients may not be so harmful as people thought before.

Animals↗

PubMed1998

[Induction of insulin-like growth factor I expression to mandibular advancement in growing rat condylar cartilage].

It was studied effects of functional mandibular advancement on IGF-I peptide of condylar cartilage of 60 5-week-old male rats. Animals were randomly divided into the experimental and control groups, and the mimic functional appliances were used in experimental group. The rats were killed after 1, 3, 7, 14, 21 and 28 days. The results showed that the condylar cartilage of growing rats expressed IGF-I the strongest in the germinal layer, medial in the transitional layer, and the least in the maturational layer. IGF-I positive cells and their immunoreactive levels increased after 1 week of functional mandibular advancement, and reached the peak level at 2 weeks. The results suggest IGF-I in mandibular condyle of rat is related to its growth and differentiation activity, and changes of condylar IGF-I after functional protrusion are relevant to the histologic changes and cellular functions which indicate their involvement with active bone growth and remodeling.

Animals↗

PubMed1998

[Differential expression of IGF-I and its mRNA in mandibular condylar cartilage of rat--direct evidence for servosystem theory of facial growth].

It was studied the expression of IGF-I and its mRNA in the condylar cartilage of 10 7-week-old SD male rats by using in situ hybridization and immunohisto-chemistry technique. The results showed both IGF-I and its gene expressed in growing rat condyle. IGF-I peptide was abundant in germinal zone, and positive reaction of its mRNA was strongest in transitional and maturational zones. These indicate that condylar cartilage has the capability of local production and secretion of IGF-I, mediating the command effect of STH, and differential expression of IGF-I and its mRNA might establish the local feedback loop, which supply a direct evidence for servosystem theory of facial growth.

Animals↗

PubMed1998

Osteogenesis of electrically stimulated bone cells mediated in part by calcium ions.

Culture selected and expanded osteoblastic cells may be able to be reintroduced into massive skeletal defects to accelerate cell mediated regeneration of skeletal tissues, especially in bone ingrowth in total joint replacement, fracture healing, and osteoporosis. In vitro osteogenic cell culture is a useful model in studying the mechanism of bone metabolism under direct current stimulation. In this study, an osteoblastlike cell line was isolated from newborn rat calvaria. The osteogenic processes of the in vitro cultured cell line were studied by cytochemical, electron microscopic, and energy dispersive x-ray analysis techniques that resembled those observed in membrane bone ossification centers in vivo. Direct current stimulation of 100 microA/cm2 accelerated greatly the proliferation and calcification of the in vitro cultured cells. Intracellular free calcium ion metabolism was measured with an Adherent Cell Analysis and Sorting Machine. Under direct current stimulation, intracellular free calcium ion concentration increased an average of 2.3 times of the original level, which may play a key role in regulating osteogenesis and bone metabolism.

Alkaline Phosphatase↗

PubMed1997

Long-term inhibitory effects of a novel anti-estrogen on the growth of ZR-75-1 and MCF-7 human breast cancer tumors in nude mice.

The effects of the novel anti-estrogen EM-343 on the growth of 2 hormone-responsive human breast cancer tumors have been examined in athymic nude mice. At the low daily dose of 5 microg, EM-343 administered subcutaneously for 6 months completely blocked the stimulatory effect of endogenous estrogens on the growth of ZR-75-1 and MCF-7 tumors implanted in nude mice. In addition, uterine weight decreased by 60% while ovarian weight increased by 37%. Estrogen receptor (ER) levels measured by [3H]-labeled estrogen binding were markedly reduced (by 96%, 96% and 92%) in ZR-75-1 and MCF-7 tumors, and in the mouse uterus, respectively. Accompanying the decrease in ER, progesterone receptor levels were reduced by 79%, 87% and 76%, respectively, in the above-mentioned tissues following EM-343 treatment. Our data show the pure anti-estrogenic properties of EM-343 and its high potency as an inhibitor of growth of human ZR-75-1 and MCF-7 breast tumors in nude mice.

Animals↗

PubMed1997

Inhibitory effect of the novel anti-estrogen EM-800 and medroxyprogesterone acetate on estrone-stimulated growth of dimethylbenz[a]anthracene-induced mammary carcinoma in rats.

The novel anti-estrogen EM-800 and medroxyprogesterone acetate (MPA) inhibit estrone (E1)-stimulated growth of dimethylbenz[a]anthracene (DMBA)-induced mammary tumors in a rat model. After 65 days, ovariectomy (OVX) decreased total tumor area to 9.6 +/- 3.9% of initial size, while E1 (1.0 microg, s.c., twice daily) stimulated tumor growth to 225 +/- 40.9% of initial size. Daily oral administration of 2.5 mg/kg body weight of EM-800 completely abolished E1-stimulated tumor growth. A low daily dose of EM-800 (0.25 mg/kg body weight) or MPA (1 mg, s.c., twice daily) used alone partially reversed the stimulatory effect of E1 on the growth of DMBA-induced tumors. The combination of both compounds, however, caused a more potent inhibitory effect than each compound used alone. A high dose of EM-800 completely or almost completely inhibited the E1-stimulated vaginal and uterine weights, respectively. The same dose of EM-800 completely reversed the inhibitory effect of E1 on serum luteinizing hormone levels. Uterine, vaginal and tumoral estrogen and progesterone receptor levels were reduced markedly following treatment with EM-800. Our data show that the combination of the pure anti-estrogen EM-800 with the androgenic compound MPA achieves greater inhibition of the growth of DMBA-induced mammary carcinoma than that achieved by each compound used alone.

9,10-Dimethyl-1,2-benzanthracene↗