50joe said:
Heck yes! If you could get some good reading up for us, I'm sure everyone would really appreciate it!
Not a problem guys. I have access to one of the largest collections of medical journals in the country...so if you've got questions I'd be happy to help. To give you an idea, MEDLINE is one of several databases for these articles and medline has almost all of the journal articles from around the world that have been published since 1966. Basically, if it's been studied and published, I can find it. I'm at home right now, so I will post some of the online articles that I can find from MEDLINE. I'll be in the library sometime this weekend and will have access to all of the paper copies of these journals...so i'll be able to find more. You see, there are a limited number of articles that are still kept in their full text online (still a lot but not nearly my school's entire collection). The rest are all in bound journals at the school library. Anyways, I'll post some of the abstracts (articles are really long to post) and you can let me know which you'd like to see more info on and I'll go look it up.
Here goes:
Unique Identifier 14602755
Authors von Eckardstein S. Noe G. Brache V. Nieschlag E. Croxatto H. Alvarez F. Moo-Young A. Sivin I. Kumar N. Small M. Sundaram K. International Committee for Contraception Research, The Population Council.
Institution Institute of Reproductive Medicine, University of Munster, Munster, Germany.
Title A clinical trial of 7 alpha-methyl-19-nortestosterone implants for possible use as a long-acting contraceptive for men.
Source Journal of Clinical Endocrinology & Metabolism. 88(11):5232-9, 2003 Nov.
Abstract Several preparations of testosterone and its esters are being investigated alone or in combination with other gonadotropin-suppressing agents as possible antifertility agents for men. We studied the effectiveness of 7 alpha-methyl-19-nortestosterone (MENT) as an antispermatogenic agent in men. MENT has been shown to be more potent than testosterone and to be resistant to 5 alpha-reduction. For sustained delivery of MENT, we used a system consisting of ethylene vinyl acetate implants containing MENT acetate (Ac), administered subdermally. Thirty-five normal volunteers were recruited in 3 clinics and were randomly assigned to 1 of 3 doses: 1 (12 men), 2 (11 men), or 4 (12 men) MENT Ac implants. The initial average in vitro release rate of MENT Ac from each implant was approximately 400 micro g/day. Implants were inserted subdermally in the medial aspect of the upper arm under local anesthesia. The duration of treatment was initially designed to be 6 months. However, in 2 clinics the duration of treatment was extended to 9 months for the 2-implant group and to 12 months for the 4-implant group. Dose-related increases in serum MENT levels and decreases in testosterone, LH, and FSH levels were observed. Effects on sperm counts were also dose related. None of the subjects in the 1-implant group exhibited oligozoospermia (sperm count, <3 million/ml). Four subjects in the 2-implant group became oligozoospermic, 2 of whom reached azoospermia. Eight subjects in the 4-implant group reached azoospermia, with 1 exhibiting oligozoospermia, whereas 2 were nonresponders. Side effects generally seen with androgen administration, such as increases in erythrocyte count, hematocrit, and hemoglobin and a decrease in SHBG, were also seen in this study and were reversible. Changes in lipid parameters were moderate and transient. Liver enzymes showed small changes. This study demonstrates that MENT Ac, when administered in a sustained release fashion via subdermal implants, can inhibit spermatogenesis over a prolonged period after a single administration and has the potential to be used as a male contraceptive.
Unique Identifier 12788888
Authors Anderson RA. Wallace AM. Sattar N. Kumar N. Sundaram K.
Institution Medical Research Council Human Reproductive Sciences Unit, University of Edinburgh, Edinburgh, United Kingdom EH16 4SB.
[email protected]
Title Evidence for tissue selectivity of the synthetic androgen 7 alpha-methyl-19-nortestosterone in hypogonadal men.
Source Journal of Clinical Endocrinology & Metabolism. 88(6):2784-93, 2003 Jun.
Abstract The potent synthetic androgen 7 alpha-methyl-19-nortestosterone (MENT) is resistant to 5 alpha-reductase but is a substrate for aromatase. It may therefore offer selective sparing of the prostate gland while supporting other androgen-dependent tissues. MENT acetate implants were administered for 24 wk to 16 hypogonadal men, randomly allocated to 1 or 2 implants (groups I and II, respectively; releasing approximately 400 microg/d x implant). Hemoglobin concentration and hematocrit were maintained during MENT treatment. Prostate volume fell in group I and to a small, but statistically nonsignificant, degree in group II; the level of prostate-specific antigen fell significantly in both. Lumbar spine bone mineral density decreased in both groups. Sexual behavior and erectile function declined in group I, but were maintained in group II. Thus, overall, one MENT implant appeared to provide subphysiological androgen replacement. The 2-implant dose of MENT was able to maintain most androgen-dependent functions, except bone mass, and there was evidence to support selective sparing of the prostate gland. These results demonstrate for the first time in humans the selectivity of MENT in tissues dependent on 5 alpha-reductase. In addition, our data are consistent with the importance of adequate estrogenicity as part of the necessary spectrum of activity of an androgen for replacement therapy in men.
Unique Identifier 10522995
Authors Anderson RA. Martin CW. Kung AW. Everington D. Pun TC. Tan KC. Bancroft J. Sundaram K. Moo-Young AJ. Baird DT.
Institution Medical Research Council Reproductive Biology Unit, Center for Reproductive Biology, Edinburgh, Scotland.
[email protected]
Title 7Alpha-methyl-19-nortestosterone maintains sexual behavior and mood in hypogonadal men.
Source Journal of Clinical Endocrinology & Metabolism. 84(10):3556-62, 1999 Oct.
Abstract The synthetic steroid 7alpha-methyl-19-nortestosterone (MENT) is a potent androgen that is resistant to 5alpha-reductase. It thus has decreased activity at the prostate and may have advantages over testosterone-based regimens in long term treatment or as part of a male contraceptive. Administration to eugonadal men results in suppression of gonadotropins, but its ability to support androgen-dependent behavior has not been investigated. For sustained release administration, MENT acetate was used, because its diffusion characteristics were more suitable for use in implants. However, upon release the acetate is rapidly hydrolyzed, and MENT is the biologically active moiety in circulation. We studied the effects of MENT on sexual interest and activity, spontaneous erection, and mood states in comparison with testosterone enanthate (TE) in 20 Caucasian and Chinese hypogonadal men recruited in Edinburgh and Hong Kong (n = 10 in each center). Outcomes were measured using a combination of daily diaries, semistructured interviews, and questionnaires. Nocturnal penile tumescence (NPT) was also recorded in the Edinburgh group. After withdrawal of androgen replacement treatment (wash-out phase) for a minimum of 6 weeks, subjects were randomized to two groups in a cross-over design. Drug treatment regimens were of 6-week duration and consisted of two implants, each containing 115 mg MENT acetate, inserted s.c. into the upper arm and removed after 6 weeks and two injections of TE (200 mg, i.m.) 3 weeks apart. MENT treatment resulted in stable plasma MENT concentrations of 1.4 +/- 0.1 nmol/L after 3 weeks and 1.3 +/- 0.1 nmol/L after 6 weeks (mean +/- SEM; all men). Nadir testosterone concentrations were 3.6 +/- 0.6 nmol/L at the end of the wash-out phase and 9.4 +/- 0.6 nmol/L 3 weeks after each injection. There were no differences in hormone concentrations between centers. There were no adverse toxicological effects. There were only minor differences between the two treatments. Both MENT and TE treatment resulted in significant increases in sexual interest and activity, spontaneous erection (both by self-report and NPT measurement), and increases in positive moods, with decreases in negative moods in the Edinburgh group. In the Hong Kong group, both treatments increased waking erection, with a trend toward increased sexual interest and activity. Mood states appeared to be less affected during the wash-out phase than in Edinburgh men and showed no significant response to either treatment. These results demonstrate that MENT has similar effects on sexual activity and mood states as testosterone in hypogonadal men. As NPT is a physiological androgen-dependant outcome, these data provide further evidence for the androgenicity of MENT. The lack of detected effect of either androgen in Hong Kong men other than on waking erection illustrates the importance of the cultural context of symptomatology and its measurement. The appropriate dose of MENT remains to be determined, but these results support its development as a potential androgen replacement therapy.