Effects of an antiprogesterone (RU486) on the hypothalamic-hypophyseal-ovarian-endometrial axis during the luteal phase of the menstrual cycle

The impact of the antiprogesterone RU486 [17 beta-hydroxy-11 beta-(4-dimethylaminophenyl) 17 alpha-(1-propynyl)estra- 4,9-dien-3-one] on the hypothalamic-pituitary-ovarian-endometrial axis was examined in normal cycling women during the mid (MLP)- and late (LLP) luteal phases. During the MLP, 10 women received 3 mg/kg RU486 for 3 days. During the LLP, a single dose of 600 mg RU486 was administered to 4 women, and in another 4 women a single dose of 3 mg/kg was given during corpus luteum rescue by hCG. Longitudinal studies with daily and frequent blood samples (every 10 min for 10 h) were conducted during 3 consecutive cycles (control-treatment-recovery). During the MLP, RU486-induced uterine bleeding occurred in all 10 women 36-72 h after the first dose. No histological evidence of endometrial breakdown was found in endometrial biopsies taken 12-24 h before the onset of bleeding. Significant decreases in LH secretion (P less than 0.001) and LH pulse amplitude (P less than 0.006) and blunted pituitary responses to GnRH (P less than 0.01) were evident by the last treatment day, but LH pulse frequency did not change. Complete luteolysis occurred in 2 of the 10 women. Incomplete luteolysis occurred in 8 women and was associated with an initial decline of serum estradiol (P less than 0.001), but not progesterone levels, followed by rebound increases (P less than 0.001) in LH, estradiol, and progesterone levels 3 days later, which may have reversed the luteolytic processes and prolonged corpus luteum function. Spontaneous luteolysis ensued 3-5 days later with the onset of second episodes of uterine bleeding. For serum FSH, an early rise occurred during the luteal phase in advance of the onset of the second episodes of uterine bleeding. This rise may have resulted in early follicle recruitment and accounted for the shorter duration of the follicular phase during recovery cycles. During the LLP, the single RU486 dose resulted in significant decreases in LH pulse amplitude (P less than 0.03), frequency (P less than 0.05), and secretion (not significant) within 12 h. The recovery cycle was entirely normal. Corpus luteum rescue with incremental doses of hCG did not prevent uterine bleeding after RU486 treatment. These findings indicate that RU486 operates at multiple sites and implies that progesterone is important in the control of luteal function. Further, our data provide a basis for exploring the potential use of RU486 as a once a month birth control agent.

Ionic and permeability requirements for exocytosis in vitro in sea urchin eggs

We study exocytosis in the planar isolated cortex of the egg of the sea urchin Lytechinus pictus. Solutions bathing the exocytotic apparatus need not contain appreciable amounts of ions: fusion follows addition of submicromolar calcium to solutions containing only nonelectrolyte. We examine the effects of altering the granule membrane permeability to small molecules with ionophores and digitonin. Introducing holes in the secretory granule membrane to the extent of allowing free passage of small molecules does not cause secretion in vitro. We add the amphipathic compound digitonin at 12 to 15 microM concentrations and demonstrate that the granule membrane can become permeable to lucifer yellow, yet that granules remain intact. Granules still undergo exocytosis after digitonin treatment at such concentrations upon subsequent addition of calcium. Higher concentrations of digitonin lead to granule content swelling and vesicle bursting. We conclude that cortical granule hydration during exocytosis is not mediated by small ionic channels.

Treatment of uterine fibroids with agonist analogs of gonadotropin-releasing hormone

Agonist analogs of GnRH were used to effect a "medical castration" in 14 patients with uterine fibroids, presenting with either an enlarged uterus, recurrent menometrorrhagia, and/or infertility. This study confirms prior reports of a reduction in uterine size and cessation of menometrorrhagia in patients with fibroids following treatment with GnRHa. Of interest, however, was the successful use of GnRHa as either the sole treatment for uterine fibroid-associated infertility, or as a preoperative adjunct in infertility patients scheduled for myomectomy. Three of the five infertility patients in this study achieved intrauterine pregnancies. Further study of the role of GnRHa treatment in infertility patients with uterine fibroids appears warranted.

The effect of berbamine derivatives on activated Ca2+-stimulated Mg2+-dependent ATPase in erythrocyte membranes

Ca2+-stimulated Mg2+-dependent ATPase (Ca2+ + Mg2+-ATPase) stimulated by calmodulin, by partial proteolysis or by oleic acid in erythrocyte membranes was inhibited by various derivatives of the naturally occurring alkaloid berbamine. The ability of these derivatives to inhibit trypsin-activated Ca2+ + Mg2+-ATPase correlated well with their ability to inhibit the calmodulin-stimulated enzyme. Inhibition of the trypsin-activated Ca2+ + Mg2+-ATPase by O-4-(ethoxybutyl)berbamine (EBB) was competitive with respect to ATP. The Ki for inhibition was about 8 microM. These results suggest that the binding site of EBB on the activated Ca2+ + Mg2+-ATPase may bear structural similarity to that on calmodulin, and may be closely related to the ATP-binding site on the enzyme.

Vessel imaging using dual-energy tomosynthesis

A method has been developed that combines dual-energy subtraction and tomosynthesis for vessel imaging in intravenous angiography. This paper describes the procedure for doing tomosynthesis on a fan-beam rotational-motion system and gives the point responses of the imaging system. Phantom studies show that dual-energy tomosynthesis improves the visualization of desired vessels lying on a selected plane. The results may be feasible for some applications such as clinical diagnosis of coronary artery diseases.

Immunochemical probing of the N-terminus of the myosin heavy chain

The reactivity of myosin subfragment 1 (S-1) towards site specific polyclonal anti-N-terminus antibodies was examined in competitive ELISA titrations. Tryptic digestion of S-1 and specifically the cleavage at the 25/50K junction greatly increased the accessibility of the N-terminus region to the antibodies. The binding of actin to S-1 did not change significantly the reactivity of either tryptic or intact S-1 towards anti-N-terminus antibodies. These results suggest the interdependence of the N-terminus and 25/50K junction regions on S-1.

Proteolysis and binding of myosin subfragment 1 to actin

Rates of proteolytic cleavage of myosin subfragment 1 were measured in the absence and presence of different amounts of actin. The rates of tryptic digestion at the 50K/20K junction and papain digestion at the 25K/50K junction of the myosin head were progressively inhibited with increasing substoichiometric molar ratios of actin to myosin subfragment 1. The percentage inhibitions of digestion reactions corresponded precisely to the molar compositions of actin-subfragment 1 solutions and demonstrated that equimolar complexes of these proteins were responsible for the observed changes in the proteolysis of myosin heads.

Bone sarcomas associated with Ollier's disease

Of 55 patients with Ollier's disease seen at the Mayo Clinic between 1907 and 1985, 16 had malignant bone neoplasms: 12 chondrosarcomas, two dedifferentiated chondrosarcomas, one chordoma, and one osteosarcoma. One patient had a chondrosarcoma in two different bones. These findings suggest that approximately 30% of patients with Ollier's disease will develop a malignant bone neoplasm, most probably chondrosarcoma. The prognosis for most patients is good. Five of the 16 patients survived more than 13 years after treatment.

Relationship between human prostatic epithelial cell protein synthesis and tissue dihydrotestosterone level

To evaluate the role of small amounts of prostatic tissue dihydrotestosterone (DHT) as a stimulus to epithelial cell protein synthesis, we studied tissue from 27 patients given various androgen-blocking drugs for 1 week before transurethral resection of the prostate (TURP) and measured epithelial protein synthesis and DHT levels in the tissue specimens. Test drugs before TURP included megestrol acetate 160 mg per day, with and without Tamoxifen 40 mg per day, or ketoconazole 1200 mg per day. The tissue was processed immediately and epithelial cells separated by digestion of tissue with 0.5% collagenase. After separation, epithelial cells were labelled with either 3H-leucine or L-35S-methionine. The DHT level was measured in whole prostatic tissue. Megestrol acetate alone and with tamoxifen significantly decreased both the incorporation of 3H-leucine into protein and the tissue concentration of DHT; megestrol acetate plus ketoconazole significantly decreased L-35S-methionine incorporation into protein and the DHT level. When the data correlating DHT with protein synthesis using both labelling techniques were combined, the curves were parallel and a strong correlation was noted between DHT and protein synthesis over a wide range of values (P less than 0.001). These results suggest that in hormone-dependent prostatic cancer even small amounts of prostatic DHT such as may occur from adrenal androgens following castration may significantly stimulate protein synthesis of the tumour epithelial cells.

The intraocular penetration of acyclovir after subconjunctival administration

Five patients received a subconjunctival injection (25 mg) of acyclovir before undergoing scheduled enucleation. Seven hours after injection, the observed aqueous and vitreous levels of acyclovir were above the minimum inhibitory concentrations for many herpes simplex viruses types 1 and 2. Systemic absorption measured at two and seven hours after injection was negligible.

Luteal contraception

The impact of oral administration of RU 486 on the ongoing functional activity of the hypothalamic-gonadotropin-corpus luteum-endometrial (H-P-CL-E) axis was assessed during the mid-luteal (MLP) and the late-luteal phase (LLP) with and without hCG-induced pseudopregnancy. Longitudinal studies with daily dosing and frequent blood sampling were conducted during three consecutive cycles (control/treatment/recovery). During MLP, uterine bleeding occurred in all subjects within 36-72 h of the first dose of RU 486, but no histological changes were discernible on endometrial biopsy taken 12-24 h before bleeding. There was a significant decrease in LH secretion, pulse amplitude but not frequency. Response to GnRH on the last day of treatment was impaired. This was followed 3 days later by a rebound LH secretion lasting for 5 days. These events were accompanied by an initial decline of estradiol, but not progesterone, and a second peak of 5 days' duration for both estradiol and progesterone. Hence corpus luteum function was prolonged by 5 days, and second bleeding ensued following the spontaneous luteolysis. Recovery cycles were normal. During LLP, a single dose of RU 486 induced uterine bleeding in all cases. This was associated with a decreased LH pulse amplitude and frequency, and a faster decline of both estradiol and progesterone as compared to control cycles. Rescue of corpus luteum function by the administration of incremental doses of hCG failed to prevent the uterine bleeding after a single dose of RU 486. Recovery cycles were normal. While the antiprogesterone effect of RU 486 at the endometrial level was predictably expressed, its effects at the H-P-CL-E axis were also demonstrated. These findings provide important clues for the design of once-monthly contraceptive methods.

[Effect of sodium selenite on the chromosomal aberration of V 79 cells induced in vitro by MNNG and MNU]

Effect of sodium selenite on chromosomal aberration of V 79 cells induced by MNNG and MNU was studied. Na2SeO3 alone, at the concentration of 10(-7)-10(-4) M, increased the incidence of chromosomal aberration. However, Na2SeO3 at 10(-7)-10(-5) M, having been preincubated with the cells for 4 hours, could reduce the number of cells with chromosomal aberration induced by MNNG. Na2SeO3 at 10(-7)-10(-4) M inhibited mutagenic activity of chromosomal aberration induced by MNU. The same inhibition was observed even sodium selenite was added to the medium simultaneously with this carcinogen. The results indicate that sodium selenite alone, at the concentration range used in this experiment, is an aberration-inducing agent. But when combined with the carcinogen, anti-cancer effect is obtained.

[Sister chromatid exchanges (SCE), chromosomal aberrations and micronuclei of cultured peripheral lymphocytes in patients with lung cancer, miners and non-mining workers of the tin mine in Yunnan]

Determination of SCE frequency, chromosomal aberration and micronucleus rate of cultured peripheral lymphocytes in 32 patients with lung cancer, 33 miners and 40 non-mining workers in Yunnan Tin Mine was carried out. The results showed that the cancer patients had higher SCE incidence, chromosomal aberration and micronucleus rate, the non-mining workers had the least and miners on an intermediate level. There was a significant difference of SCE, chromosomal aberrations and micronucleus rate between patients and non-mining workers (P less than 0.05-0.01). We also found that miners had a significant higher SCE and chromosomal aberration rate but not micronucleus rate as compared with the non-mining workers. We proposed that some carcinogens present in the Yunnan Tin Mine be responsible for the genetic damages in the miners. Chemical drugs may be considered to contribute to the genetic damage in cancer patients who had a tendency toward an increased SCE, chromosomal aberration and micronucleus rate as compared to the miners, though without reaching a statistical significance. We suggested that combination assay of SCE with chromosomal aberration or micronucleus be an useful index for screening of the high risk population and monitoring the chemical drug prevention of lung cancers in Yunnan Tin Mine.

Nucleotide sequences of Cyanophora paradoxa cellular and cyanelle-associated 5S ribosomal RNAs: the cyanelle as a potential intermediate in plastid evolution

The 5S ribosomal RNAs from the cell cytoplasm and cyanelle (photosynthetic organelle) of Cyanophora paradoxa have been isolated and sequenced. The cellular and cyanelle 5S rRNAs were 119 and 118 nucleotides in length, respectively. Both RNAs exhibited typical 5S secondary structure, but the primary sequence of the cellular species was clearly eukaryotic in nature, while that of the organellar species was prokaryotelike. The primary sequence of the cyanellar 5S rRNA was most homologous to cyanobacterial 5S sequences, yet possessed secondary-structural features characteristic of higher-plant chloroplast 5S rRNAs. Both sequence comparison and structural analysis indicated an evolutionary position for cyanelle 5S rRNA intermediate between blue-green alga and chloroplast 5S rRNAs.

[Ultrastructure of primary clear cell carcinoma of the liver]

Surgical specimens of 175 cases of primary hepatocellular carcinoma were prepared by routine paraffin section and HE stain. The clear cell cancer specimens were stained with PAS. All the specimens were observed by light microscope. Ultrathin sections were made for 50 samples and studied by electron microscope. Under the light microscope, 79 (45.1%) showed varying amounts of clear cells. According to the proportion and distribution of these cells, clear cell carcinoma of the liver was divided into three types: scattered type (16 cases, 20.3%), localized (43, 54.4%) and diffuse types (20, 25.3%). The clear cancer cells could be found in hepatoma with various degrees of differentiation. Of these 79 cases, 4 (5.1%) were grade I, 53 (67%) and 22 (27.9%) were grades II and III. Positive PAS stain gives an evidence of glycogen in the clear cell cytoplasm. 7 diffuse type clear cell hepatomas were observed with electron microscope. The cytoplasm had only fewer organelles, leading to a void appearance. The amount of the rough endoplasmic reticulum, free ribosome and polyribosome was markedly decreased. So was mitochondria, usually showing swelling and abnormality. The residual rough endoplasmic reticulum and mitochondria were out of normal arrangement. They often aggregated on one side of the nucleus or near the cell membrane. Glycogen particles were increased in some cell cytoplasms. Some particles were even and fine, some were aggregated into masses or scattered. Nuclei showed abnormalities mild to moderate. The nature of the clear cells in liver cancer is the variance of glycogen or lipid in the cytoplasm.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of antiandrogen and/or antiestrogen blockade on human prostate epithelial and stromal cell protein synthesis

To evaluate the role of small amounts of DHT in prostate tissue as a stimulus to epithelial cell growth (protein synthesis) we studied tissue from patients given various androgen-blocking drugs prior to transurethral resection of the prostate (TURP) and measured epithelial protein synthesis and DHT in the tissue specimens. We also studied the effects on stromal cell protein synthesis of an antiestrogen, tamoxifen. Test drugs prior to TURP included Megace 160 mg per day, Megace 160 mg per day plus Tamoxifen 40 mg per day, Megace 160 mg a day plus ketoconazole 1200 mg per day and tamoxifen 40 mg/day. The tissue was processed immediately and epithelial and stromal cells separated by digestion of tissue with 0.5% collagenase. After separation, epithelial cells were labeled with either [3H]leucine or L-[35S]methionine. Stromal cells were labelled with [3H]proline. DHT was measured in whole prostate tissue. Megace alone and Megace plus tamoxifen significantly decreased both [3H]leucine incorporation into protein and tissue concentration of DHT; Megace plus ketoconazole significantly decreased L-[35S]methionine incorporation into protein and DHT. Tamoxifen significantly decreased stromal protein synthesis. When the data correlating DHT with epithelial protein synthesis using both labeling techniques were combined, the curves were parallel and a strong correlation was noted between DHT and protein synthesis over a wide range of values (P less than 0.001). These results suggest that in hormone-dependent prostate cancer even small amounts of prostate DHT such as may occur from adrenal androgens following castration may significantly stimulate growth of the tumor epithelial cells. Since tamoxifen decreased stromal protein synthesis, estrogen is likely a significant growth stimulus to the increased stromal mass characteristic of benign prostatic hypertrophy.

Does positive hepatobiliary scan in cholecystitis stay positive, and for how long?

A prospective study of 11 patients who had undergone two sequential hepatobiliary scans prior to surgery demonstrated that initially positive scans could be due to acute cholecystitis, or chronic cholecystitis with exacerbation. A second hepatobiliary scan performed four to five days later differentiated acute from chronic cholecystitis. All five patients with surgery-proven acute cholecystitis remained hepatobiliary-positive, while patients with surgery-proven chronic cholecystitis reverted back to negative hepatobiliary scans if the second hepatobiliary scan was done properly.

Gas Chromatographic Determination of Propachlor in Pesticide Formulations: Collaborative Study

An isothermal gas chromatographic (GC) method for measuring propachlor in formulations was tested by 12 collaborators. Samples are prepared in acetone and determined using a GC column of 10% SP-2250 on 100-200 mesh Supelcoport, and diisobutyl phthalate as internal standard. Collaborators made single determinations on each of 2 similar materials (matched pairs) on 2 days for 3 pairs of samples. The study generated 62 matched pairs which were used in Youden’s matched pair calculations. The coefficients of variation (CV,) for flowable formulations were 0.84 and 1.48%; the CV, for the granular formulation was 1.28%. The method was simple to use and did not reveal any interferences in the samples tested. The method has been adopted official first action as an AOAC-CIPAC method.

Gas Chromatographic Determination of Butachlor in Formulations: Collaborative Study

An isothermal gas chromatographic (GC) method for measuring butachlor in formulations was tested by 15 laboratories. Samples were prepared in acetone and determined using a GC column of 10% SP-2250 on 100-120 mesh Supelcoport, and triphenyl phosphate as internal standard. Collaborators made single determinations on each of 2 similar materials (matched pairs) on 2 days for 2 pairs of samples. The study generated 56 matched pairs which were used in Youden’s matched pair calculations. Coefficients of variation (CV,) for liquid formulations were 1.06 and 0.98%. The method was simple to use and did not reveal any interferences in the samples tested. The method has been adopted official first action as an AOAC-CIPAC method.

Intraocular 9-([2-hydroxy-1-(hydroxymethyl) ethoxy] methyl) guanine levels after intravitreal and subconjunctival administration

Clearance studies in rabbits following intravitreal injection of 400 micrograms of 9-([2-Hydroxy-1-(hydroxymethyl)ethoxy]methyl) guanine demonstrated levels of the antiviral at 60 hours above the in vitro ID50 for several strains of human cytomegalovirus. Intravitreal administration of this new antiviral may have therapeutic application in the treatment of acute retinal necrosis and cytomegalovirus retinitis complicating acquired immune deficiency syndrome (AIDS).

Isolation and sequence analysis of the gene (cpdB) encoding periplasmic 2',3'-cyclic phosphodiesterase

The cpdB gene encodes a periplasmic 2',3'-cyclic phosphodiesterase (3'-nucleotidase). This enzyme has been purified previously and the gene is located at 96 min on the Escherichia coli chromosome. In this study the cpdB gene was cloned from ClaI-cleaved DNA, and the gene product was identified. DNA blotting experiments showed that the recombinant plasmid contains a deletion with respect to the expected genomic fragment of approximately 4 kilobases, which extends into the vector. Furthermore, the gene was absent from three other recombinant libraries. Together, these findings suggest the presence in the genome of an adjacent gene whose product is lethal when it is present on a multicopy plasmid. The nucleotide sequence of the cpdB gene was also determined. The 5' and 3' untranslated sequences contain characteristic sequences that are involved in the initiation and termination of transcription, including two possible promoters, one of which may contain two overlapping -10 sequences. A strong Shine-Dalgarno sequence is followed by an open reading frame which corresponds to a protein having a molecular weight of 70,954. The first 19 amino acid residues have the characteristics of a signal peptide. The 3' untranslated sequence contains two putative rho-independent transcription terminators having low thermodynamic stability.

Effects of androgen blockade with ketoconazole and megestrol acetate on human prostatic protein patterns

We studied the effects of megestrol acetate (MA) and ketoconazole (KC) on protein synthesis of epithelial and stromal cells of human prostate. Patients with benign prostatic hypertrophy (BPH) were treated with MA (160 mg/day) plus KC (1,200 mg/day) for 7 days. Prostate tissues obtained from transurethral resection (TURP) were separated into epithelial and stromal cells with 0.5% collagenase. The separated cells were incubated with L-35S-methionine in methionine-free MEM at 37 degrees C for 3 hr. The protein synthesis in both epithelial and stromal cells was significantly inhibited in the group treated with MA and KC when compared to a control group (p less than 0.05). The proteins incorporated with L-35S-methionine were analyzed by SDS-PAGE and autoradiography. The molecular weights of the epithelial and stromal proteins inhibited ranged between 35-55K.

A comparative study of the effects of tetrodotoxin and the removal of external Na+ on the resting potential: evidence of separate pathways for the resting and excitable Na currents in squid axon

To investigate whether the Na permeability of the resting membrane is determined predominantly by the excitable Na channel, we examined the effects of tetrodotoxin (TTX) and the complete removal of external Na+ on the resting potential. In the intact squid axon bathed in K-free artificial seawater, both TTX and the removal of Na+ produced small hyperpolarizations. The effect of Na removal, however, was larger than that of TTX. In the perfused squid axon, the hyperpolarization produced by the removal of external Na+ was greatly enhanced when the internal K concentration ([K+]i) was reduced. The effect of TTX, on the other hand, was not sensitive to the [K+]i or to the membrane potential. For [K+]i = 50 mM and [K+]o = 0, the average hyperpolarization produced by TTX was 1.2 mV, while the hyperpolarization produced by Na removal was approximately 21 mV. The difference between these two effects suggests that the majority of the resting Na current passes through pathways other than the excitable Na channel.

Effect of allopurinol on the utilization of purine degradation pathway intermediates by tobacco cell cultures

Suspension cultured Nicotiana tabacum (tobacco) cells grow slowly on intermediates of the purine degradation pathway (hypoxanthine, xanthine, uric acid, allantoin, and urea) as their sole nitrogen source indicating that this degradation pathway is operative in these cells. The hypoxanthine analog, allopurinol inhibited tobacco cell growth on hypoxanthine but not uric acid. This helps confirm that the site of action of allopurinol is the conversion of hypoxanthine to uric acid by xanthine oxidase. Attempts to select cells which could grow in the presence of allopurinol with hypoxanthine as the nitrogen source were not successful.

Bioavailability of selenium to residents in a low-selenium area of China

For 8 wk 5 groups of 10 men each were given 0.5 g/day DL-methionine, 150 micrograms Se/day as sodium selenite with or without methionine or 150 micrograms Se/day as selenomethionine with or without methionine. Twenty subjects received placebo as controls. Initially plasma Se rose more rapidly than RBC Se. Increases in Se levels were significantly greater with selenomethionine than with the selenite supplement. In the placebo and methionine supplemented groups neither plasma nor RBC Se varied significantly over the course of the study. Supplementation with selenium resulted in marked increases in plasma and RBC GSH-Px within 2 and 4 wk, respectively. Plasma and RBC GSH-Px activity did not differ significantly between Se-supplemented groups. These studies suggest that selenomethionine-Se was more effective in raising plasma and RBC Se than was selenite-Se. Methionine supplements may increase the bioavailability of selenium in severely deficient subjects.

Selenium intake and metabolic balance of 10 men from a low selenium area of China

Selenium intake and urinary and fecal Se excretion of 10 healthy men from a low Se area in China were determined for three consecutive days, in summer, fall, and winter of 1983, and the spring of 1984 while self-selected diets were being consumed. Mean daily Se intake was 8.8 micrograms/day with a range of 2.3-35.5 micrograms/day, and was far below the recommended range of safe and adequate Se intake of 50-200 micrograms Se/day (National Academy of Sciences/National Research Council). Mean urinary and fecal Se outputs were 3.7 and 3.4 micrograms Se/day, respectively. Mean Se balance during this time was +1.8 micrograms Se/day. Apparent absorption of Se approximated 57%. The low Se intake in this area is a cause for concern since the residents of Molimo may be at risk for Se deficiency diseases.

Acute effects of testicular and adrenal cortical blockade on protein synthesis and dihydrotestosterone content of human prostate tissue

To examine the relationship between whole prostatic dihydrotestosterone (DHT) concentrations and epithelial and stromal protein synthesis, patients awaiting surgery for benign prostatic hypertrophy were given medication to reduce circulating and tissue androgen levels for comparison to levels in untreated patients. The medications, either megestrol acetate, a progestational antiandrogen, or megestrol acetate plus dexamethasone, were given for 1 week before surgery. Aliquots of prostate tissue obtained at surgery were assayed for DHT. The remainder of the tissue was separated into stromal and epithelial cells using enzymatic separation; the incorporation of both [3H] proline into stromal protein and [3H]leucine into epithelial cell protein was then measured. Over a wide range of tissue DHT concentrations, DHT correlated significantly with [3H]proline incorporation into stromal protein (r = 0.58). Likewise, epithelial cell incorporation of [3H]leucine into protein correlated significantly with tissue DHT concentrations, with a r value of 0.79. In the case of stromal cells, no additional effects of dexamethasone given with megestrol acetate were found on stromal protein synthesis. Epithelial cell [3H]leucine incorporation into protein was paradoxically enhanced by dexamethasone plus megestrol acetate compared to the latter alone, despite the fact that tissue DHT and circulating adrenal androgens, dehydroepiandrosterone sulfate and delta 4-androstenedione, were not significantly different from values obtained after treatment with megestrol acetate alone. These studies support the conclusion that there is a dominant role of DHT in regulating protein synthesis in both prostatic epithelial and stromal cells. Dexamethasone appears to have a growth-stimulating effect on prostatic epithelial cells.