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PubMed1978

Conservative treatment of endometriosis externa: the effects of methyltestosterone therapy.

Twenty-four women with documented endometriosis externa were treated with methyltestosterone. Twenty-one of these patients desired fertility and three conceived (one after methyltestosterone therapy alone, two after conservative operation followed by methyltestosterone treatment). Ten patients later required surgical therapy for recurrence of pain, although all but one patient had initial relief of pain (3 to 6 months after therapy). These results of therapy are contrasted to those of similar studies in the literature in which methyltestosterone and other agents were used.

Adult↗
PubMed1983

Metabolism of 17 alpha-methyltestosterone in the rabbit: C-6 and C-16 hydroxylated metabolites.

17 alpha-Methyltestosterone and the reduced metabolites, 17 alpha-methyl-5 alpha-androstane-3 alpha, 17 beta-diol, 17 alpha-methyl-5 alpha-androstane-3 beta, 17 beta-diol and 17 alpha-methyl-5 beta-androstane-3 alpha, 17 beta-diol, together with three hydroxylated metabolites, 17 alpha-methyl-5 beta-androstane-3 alpha, 16 alpha, 17 beta-triol, 17 alpha-methyl-5 beta-androstane-3 alpha, 16 beta, 17 beta-triol and a new metabolite, 17 alpha-methyl-5 alpha-androstane-3 beta, 6 alpha, 17 beta-triol, were isolated and identified in the urine of rabbits dosed with 17 alpha-methyltestosterone. No hydroxylated 5 alpha-metabolite of 17 alpha-methyltestosterone has been identified previously. No of 17 alpha-methyltestosterone has been identified previously. No evidence for epimerization at the C-17 position was observed.

Animals↗
PubMed2001

Methyltestosterone pharmacokinetics and oral bioavailability in rainbow trout (Oncorhynchus mykiss).

14C-methyltestosterone pharmacokinetics after intraarterial (2 and 20 mg/kg) and oral (30 mg/kg) administration were investigated in rainbow trout at 15 degrees C. Plasma concentrations of methyltestosterone were determined by reverse phase high performance liquid chromatography (HPLC) in combination with reverse isotope dilution for up to 6 and 12 days after oral and intraarterial administration, respectively. Methyltestosterone pharmacokinetic parameter values after intraarterial administration were determined using a two compartment model (WinNonlin). For the 2 and 20 mg/kg doses, respectively, the parameter values were, area under the plasma concentration-time curve (11.2 and 82.3 micromol h/l), total body clearance (0.640 and 0.903 l/h per kg), distribution half-life (4.13 and 8.23 h), elimination half-life (54.9 and 58.6 h), volume of the central compartment (3.83 and 13.9 l/kg), volume of distribution at steady state (6.06 and 26.8 l/kg), and the mean residence time (9.57 and 22.7 h). After oral administration, the following parameter values were assessed using a model-independent method, peak concentration (3.03 micromol/l), time of concentration peak (8.80 h), mean absorption time (13.8 h), and area under curve (AUC)(0-->infinity) (90.2 micromol h/l). A two compartment model analysis of the average plasma concentration-time profile after oral administration showed that absorption followed first-order kinetics with a half-life of 4.7 h. The oral bioavailability of methyltestosterone from food was about 70%.

Administration, Oral↗
PubMed2003

17alpha-methyltestosterone: 28-day oral toxicity study in the rat based on the "Enhanced OECD Test Guideline 407" to detect endocrine effects.

A 28-day oral gavage toxicity study in the rat with 17alpha-methyltestosterone was conducted as part of the international validation exercise on the modified Enhanced OECD Test Guideline 407 (Organisation for Economic Co-operation and Development, Paris). Special emphasis was placed on the endocrine mediated effects exerted by 17alpha-methyltestosterone, a potent androgen agonist. The test compound was administered daily by oral gavage for at least 28 days to groups of 7-week-old-Wistar rats. Dose levels were 0, 10, 40 and 200 mg/kg body weight per day for males and 0, 10, 100 and 600 mg/kg body weight per day for females. In addition, and outside the remit of the enhanced protocol, testosterone levels in males, oestradiol levels in females and luteinizing hormone (LH) levels in both sexes were measured, to provide a broader profile on the hormonally mediated effects of 17alpha-methyltestosterone. Furthermore, stage-specific quantification of Terminal deoxynucleotidyl transferase-mediated dUTP Nick-End Labeling (TUNEL)-labeled germ cells (apoptotic germ cells) in the seminiferous tubules was also performed, in an effort to demonstrate the precise stages in the spermatogenic cycle 17alpha-methyltestosterone exerts its effect. In this study, the most critical additional parameters contained in the Enhanced OECD Test Guideline 407 for the detection of endocrine disruption were considered to be the histopathological assessment and organ weight data of endocrine-related tissues. Beyond the scope of this validation exercise, an increase in apoptosis in specific germ cell types was detected using the TUNEL assay in male rats treated at 200 and 40 mg/kg.

Administration, Oral↗
PubMed2004

Effect of the combination of methyltestosterone and esterified estrogens compared with esterified estrogens alone on apolipoprotein CIII and other apolipoproteins in very low density, low density, and high density lipoproteins in surgically postmenopausal women.

Androgens are known to lower plasma triglycerides, an independent risk factor for coronary heart disease (CHD). Triglycerides are carried in plasma on very low density (VLDL) and low density (LDL) lipoprotein particles. Apolipoprotein CIII (apoCIII), a strong predictor of CHD, impairs the metabolism of VLDL and LDL, contributing to increased triglycerides. The objective of this study was to assess the effect of oral methyltestosterone (2.5 mg/d), added to esterified estrogens (1.25 mg/d), on concentrations of apolipoproteins and lipoproteins, specifically those containing apoCIII, compared with esterified estrogens alone in surgically postmenopausal women. The women in the methyltestosterone plus esterified estrogen group had significant decreases in total triglycerides, apoCI, apoCII, apoCIII, apoE, and high density lipoprotein (HDL) cholesterol compared with those in the esterified estrogen group. The decreases in apoCIII concentrations occurred in VLDL (62%; P = 0.02), LDL (35%; P = 0.001), and HDL (17%; P < 0.0001). There were also decreases in cholesterol and triglycerides concentrations of apoCIII containing LDL, and apoCI concentration of apoCIII containing VLDL. There was no effect on VLDL and LDL particles that did not contain apoCIII or on apoB concentrations. In conclusion, methyltestosterone, when administered to surgically postmenopausal women taking esterified estrogen, has a selective effect to reduce the apoCIII concentration in VLDL and LDL, a predictor of CHD. Methyltestosterone may lower plasma triglycerides through a reduction in apoCIII.

Administration, Oral↗
PubMedDate not supplied

[Adaptative effect of methyltestosterone on the protective behavior of male rats].

It was shown that male rats castrated one month before the experiment, were not able to pass into a dark cage from a light one, if the excitation, produced by the electrode floor between dark and light parts, was slightly higher than that of the pain threshold. Neither affiliation nor sexual desire change their passing ability. Methyltestosterone injections in doses of 25 mg/kg intraperitoneally 30 minutes before castration markedly enhance the capacity of the same male rats to realize the passage into a dark cage, owing to an almost double fall of the pain threshold and increased pain tolerance. Methyltestosterone affiliation and sexual desire stimulate the pain barrier overcoming at the moment of passing into a dark cage. Methyltestosterone analgesic activity was found to be 5 times more powerful when studied in the cage, allowing the passage into a dark cage, in contrast to the similar test performed under a bell glass. The results obtained illustrate an adaptive methyltestosterone role in the form studied in non-sexual specific protective behaviour.

Adaptation, Physiological↗
PubMed1993

A comparison of esterified estrogens with and without methyltestosterone: effects on endometrial histology and serum lipoproteins in postmenopausal women.

OBJECTIVE: To compare the efficacy and safety of esterified estrogens with and without methyltestosterone. METHODS: Twenty-six women participated in a double-blind randomized trial for 6 months. Outcome measures included serum total and lipoprotein-bound cholesterol, vasomotor symptoms, vaginal cytology and endometrial histology, and chemistry values. Analysis of variance and t test statistics were used to assess differences. RESULTS: After 6 months of therapy, the treatment groups were comparable with regard to symptom scores, vaginal cytology and endometrial histology scores, and clinical laboratory test values. Treatment with esterified estrogens plus methyltestosterone significantly decreased total cholesterol, high-density lipoprotein cholesterol (HDL), HDL2, HDL3, and apolipoprotein A1 compared to esterified estrogens alone. CONCLUSIONS: Esterified estrogens with or without methyltestosterone were effective at reducing menopausal symptoms and were well tolerated over 6 months of continuous treatment. A significant decrease in cholesterol and apolipoproteins in the estrogen plus methyltestosterone group suggests a potentially adverse impact on the beneficial effect normally imparted by estrogen therapy.

Adult↗
PubMed1979

Spontaneous rupture of a liver cell adenoma after long term methyltestosterone: report of a case successfully treated by emergency right hepatic lobectomy.

A case of spontaneous rupture of a liver cell adenoma is reported in a female transexual treated with methyltestosterone 150 mg daily for 7 years. Emergency right hepatic lobectomy was performed successfully. Histology showed peliosis hepatis also. Emergency resection of a liver cell adenoma has been reported in a young woman taking oral contraceptives, and an elective resection in another female transexual treated with methyltestosterone. However, to the best of our knowledge this is the first case of emergency resection of a spontaneously ruptured liver cell adenoma in a transexual treated with long term methyltestosterone. Since there are numerous other patients similarly treated, it may be expected that this complication will be seen again.

Adult↗
PubMed1991

Gas chromatographic assay of methyltestosterone in tablets.

A simple gas chromatographic procedure has been developed for the determination of methyltestosterone in bulk powders and in tablets. Two new silyl ether derivatives of methyltestosterone have been prepared using dimethylethylsilylimidazole (DMESI) and dimethylisopropylsilylimidazole (DMiPSI). The method is accurate and selective for methyltestosterone within the concentration range 0.1-1.5 micrograms microliters-1.

Chromatography, Gas↗
PubMed2006

Esterified estrogens combined with methyltestosterone raise intraocular pressure in postmenopausal women.

PURPOSE: To investigate the effect of esterified estrogens combined with methyltestosterone (EECM) (Estratest, Solvay, Pharmaceuticals, Inc, Baudette, Minnesota, USA) on intraocular pressure (IOP) in postmenopausal women. DESIGN: Observational case series. METHODS: The IOP of 13 consecutive postmenopausal women with dry eye syndrome were recorded before and during EECM therapy (1.25 mg of esterified estrogens and 2.5 mg of methyltestosterone for several months). RESULTS: The mean IOP increased from a baseline of 15.0 mm Hg before treatment to 18.2 mm Hg on EECM therapy (P < .0001) after a median duration of 11.3 months (range, 0.9 to 24 months). The increase in IOP was statistically significant at the 0.05 level of significance within three months and continued over 12 months. Two patients whose pressures increased (>4 mm Hg) returned to baseline levels after EECM was discontinued. CONCLUSIONS: Esterified estrogens combined with methyltestosterone produce a clinically significant increase in IOP in postmenopausal women with dry eye syndrome.

Aged↗
PubMed2005

Development and validation of a high performance liquid chromatography assay for 17alpha-methyltestosterone in fish feed.

17alpha-Methyltestosterone (MT) is used to manipulate the gender of a variety of fish species. A high performance liquid chromatography (HPLC) internal standard method for the determination of 17alpha-methyltestosterone in fish feed using 3beta-methoxy-17beta-hydroxyandrost-5-en-7-one as internal standard (IS) has been developed. The method has been validated for the quantitation of MT in fish feed using 245 nm UV absorbance as the parent wavelength and 255 nm as a qualifier wavelength. The method was validated in the concentration range of 15.0-120 mg/kg of 17alpha-methyltestosterone in fish feed. Method was also found to be suitable for other feeds.

Animal Feed↗
PubMed1995

Binding of 17-alpha-methyltestosterone in vitro to human sex hormone binding globulin and rat ventral prostate androgen receptors.

We measured the relative binding affinity (RBA) of 17-alpha-methyltestosterone (MET) for the rat prostate androgen receptor and human sex hormone-binding globulin (SHBG) in vitro. The reference compound in both instances was dihydrotestosterone (DHT), the RBA of which was set at 100%. The RBA of methyltestosterone was 44% for the androgen receptor, but 11% for SHBG. The androgen receptor, therefore, would appear to recognize a different part of an androgen compared to the recognition site on SHBG. The difference in RBAs may amplify the biologic action of methyltestosterone.

Animals↗
PubMed2005

[Effects of glycosides of Tripterygium wilfordii, methyltestosterone and zhuanggushenjin capsule on nitric oxide synthase in rat testes].

OBJECTIVE: To investigate the effects of glycosides of tripterygium wilfordii (GTW), methyltestosterone and Zhuanggushenjin capsule on nitric oxide synthase (NOS) in rat testes. METHODS: Forty-five rats were equally divided into 5 groups, and respectively given GTW [10 mg/(kg x d)], methyltestosterone [2 mg/(kg x d)], Zhuanggushenjin capsule [0.3 g/(kg x d)], distilled water plus Tween 80 (control I), and distilled water alone (control II) for 4 weeks. At the end of the 5th week, the immunochemical ABC method was used to observe the effects of the three drugs on the NOS positive Leydig cells of the rats. RESULTS: Compared with control II, the GTW group had a significant decrease in the numbers of nNOS and eNOS positive Leydig cells, the methyltestosterone group showed an increase in the number of nNOS but a decrease in that of eNOS positive Leydig cells, and the Zhuanggushenjin group had an increase in the numbers of both nNOS and eNOS positive Leydig cells. CONCLUSION: GTW can reduce NO production by inhibiting eNOS and nNOS, and hence influence the spermatogenic process. Zhuanggushenjin capsule plays an important role in improving male sexual function by enhancing nNOS and eNOS expression and NO synthesis.

Animals↗
PubMed2000

Aromatase inhibitor and 17alpha-methyltestosterone cause sex-reversal from genetical females to phenotypic males and suppression of P450 aromatase gene expression in Japanese flounder (Paralichthys olivaceus).

The sex of Japanese flounder (Paralichthys olivaceus) is easily altered by water temperature or sex steroid hormone treatment during the period of sex determination. We have previously shown that rearing the genetically female larvae at high water temperature caused the suppression of P450 aromatase (P450arom) gene expression in the gonad and phenotypic sex-reversal of the individuals to males (Kitano et al. 1999. J Mol Endocrinol 23:167-176). In the present study, we show that treatment of genetically female larvae with fadrozole (aromatase inhibitor) or 17alpha-methyltestosterone induces sex-reversal as well as suppression of P450arom gene expression. The effect of fadrozole was counteracted by co-administration of estradiol-17beta. Effective periods for fadrozole treatment to induce sex-reversal were similar to those for high water temperature treatment. RT-PCR did not detect P450arom mRNA in gonad of the sex-reversed, phenotypic males. These results indicate that sex-reversal of the genetically female larvae by aromatase inhibitor (or 17alpha-methyltestosterone) may be due to the suppression of P450arom gene expression and the resultant decrease in the amount of estrogen.

Animals↗
PubMed1984

The effects of long-term administration of methyltestosterone on the development of liver lesions in BALB/c mice.

Male and female BALB/c mice were treated orally with 5 mg/kg body weight of methyltestosterone for 10 months. Age-matched control animals received no steroid treatment. The livers of all animals were examined by standard histopathological methods. Hepatocellular dysplasia was found in livers of all treated mice, but not in control animals. The extent and severity of this dysplasia showed a sex difference. Most of the male mice (55/78) developed severe dysplasia and in 23/78 the dysplasia was only moderate; the corresponding numbers for female mice were: mild, 15/71; moderate, 48/71 and severe dysplasia, 8/71. Microscopic hepatocytic nodules were found in 6/78 males and 7/71 females. Hepatocellular carcinoma was seen in one male mouse. These findings indicate that methyltestosterone appears to act as a weak total hepatocarcinogen under the experimental conditions used.

Animals↗
PubMed1998

Effects of 17alpha-methyltestosterone on sexually dimorphic characters in the weakly discharging electric fish, Brienomyrus niger (Günther, 1866) (Mormyridae): electric organ discharge, ventral body wall indentation, and anal-Fin ray bone expansion.

Adult males of African weakly discharging electric fish (family: Mormyridae) are distinguished from juveniles and adult females by a dorsally directed indentation of the posterior ventral body wall and by massive bone expansion of the bases of a select number of anal-fin rays. These sexually dimorphic structures seem to facilitate the anal-fin reflex that is displayed during courtship when the male envelopes its anal fin around the female's to form a common spawning pouch. Expanded bone could provide additional surface for muscle attachment and thus assist in part with the courtship sequence. Based on the fact that the expression of the male sexually dimorphic electric organ discharge (EOD) is under androgen control, and that the female EOD can be masculinized through testosterone administration, we hypothesized that androgens should also drive anal-fin ray bone expansion in male mormyrids and equally effect male-like changes in treated juveniles and adult females. Exogenous androgen treatment (17alpha-methyltestosterone) of adult female Brienomyrus niger resulted in a male-like EOD, and male-typical structural transformations (body wall indentation and anal-fin ray bone expansion). Some of these changes were immediate and receded following hormone withdrawal (EOD), while others developed more slowly and were apparently permanent (indentation and bone formation). 17alpha-Methyltestosterone administration affected only those targets in females that are normally involved in the male's reproductive behavior, i.e., its courtship signal (EOD) and two morphological features (body-wall indentation and bone expansion). Rays of the dorsal or caudal fins were never affected.

Animals↗
PubMed1979

Incorporation of 3H-thymidine in the nephron of Gasterosteus aculeatus L. and its stimulation by methyltestosterone. A high-speed scintillation autoradiographic study.

The rate of 3H-thymidine incorporation into different parts of the renal proximal tubule of female sticklebacks treated with methyltestosterone was investigated using high-speed scintillation autoradiography. The results are compared with those from normal males before or after mucous transformation of the kidney. Labelled cells are observed in all parts of the proximal tubule, with marked variations from one segment to another. They are numerous in part 2 of the proximal tubule, particularly in the distal region. Male sex hormones affect the labelling rate in all parts of the nephron, especially in the distal region of part 2 of the proximal tubule. In that particular area, new tubule formation by budding is observed in some individuals, but this process does not appear to be a general one. Correlation between the frequency of these figures and the time of treatment could not be established. Comparing the action of sex hormones in females with that in males reveals a difference in reactivity in the proximal zone of part 2 of the proximal tubule, where methyltestosterone has a strong action in females; in contrast, in "mature" and "immature" males, only a few labelled cells are present in this region. It is concluded that kidney enlargement during the breeding season does not result only from a swelling of cells belonging to part 2 of the proximal tubule, as was generally believed, but also from a lengthening or even a proliferation of the proximal tubules, induced by an increase in mitotic activity controlled by male sex hormones.

Animals↗
PubMed2007

OECD validation of the rodent Hershberger assay using three reference chemicals; 17alpha-methyltestosterone, procymidone, and p,p'-DDE.

The rodent Hershberger assay is being validated as an in vivo test method for detecting androgenic or antiandrogenic compounds by the Organization for Economic Cooperation and Development (OECD). As part of the international validation work, we studied 17alpha-methyltestosterone for evaluating androgenic activity, and procymidone and p,p'-DDE for evaluating antiandrogenic activity. Male Sprague-Dawley rats were castrated at postnatal day 42, and only the rats that showed preputial separation were used in this study. Seven days after castration, chemicals were administered daily by gavages to groups of rats for 10 days, as recommended by OECD phase-2 protocol. Administration of 17alpha-methyltestosterone induced increases of weights of accessory sex tissues and glands in a dose-dependent manner. Administration of procymidone and p,p'-DDE produced a dose-dependent decrease of weights of accessory sex tissues and glands in the rats co-treated with testosterone propionate (0.4 mg/kg/day) subcutaneously. Our data strongly suggested that the current protocol of OECD Hershberger assay (phase-2) should be used as a reliable method for the detection of endocrine related toxicity of other chemicals.

Administration, Oral↗