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Research Chemical SciencesUGFREAKeudomestic
napsgeargenezapharmateuticals domestic-supplypuritysourcelabsResearch Chemical SciencesUGFREAKeudomestic

Nolvadex and fertility, Read!

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Title: Effect of chronic administration of Tamoxifen on fertility in male bonnet monkeys (Macaca radiata).

Researchers: Rao AJ, Ramachandra SG, Ramesh V, Krishnamurthy HN, Jayaraman S, Gopalakrishnan K, Juneja HS

Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India.

Source: Andrologia 1998 May-Jun;30(3):129-32

Summary: Administration of Tamoxifen via the Alzet pump at a rate of 50 micrograms hr-1 for 90 days in the adult male bonnet monkeys Macaca radiata had no effect on the serum testosterone concentration determined at 10 AM and 10 PM as well as total sperm count determined at 15-day intervals over a period of 260 days. However, a significant reduction in sperm motility was observed beyond 90 days up until the 225th day. Breeding studies conducted from day 90 to 260 revealed that these males were infertile.

Discussion: Tamoxifen, or Nolvadex, is classified as an antiestrogen. I’m sure most of you are already familiar with this drug. It works as an antiestrogen by competitively binding to estrogen receptors. Although it has high affinity for estrogen receptors it has little if any estrogenic effects in most tissues. It is used by bodybuilders to prevent or treat gynecomastia and water retention. The interesting thing about this study was the fact that Tamoxifen, an antiestrogen, made the male monkeys infertile. This is in agreement with another recent study looking at the effects of an aromatase inhibitor (Steroids 1998 Jul-Aug;63(7-8):414-20) on fertility also in male monkeys. Both of these studies point to an important role of estrogen in male fertility. Tamoxifen, unlike the aromatase inhibitor which caused a 2-10 fold increase in serum testosterone levels, showed no effect on serum testosterone. The effect on spermatogenesis was clearly due to estrogen. Their sperm count was fairly normal, however, the sperm couldn’t swim to save their own lives. The take home message is that if you want to start a family between shows, stay away from Nolvadex and Proviron. On the other hand, these two compounds may be potential male birth control remedies. I guess the glass is either half full or half empty depending on how you look at it.
 
Awesome post. Were there any studies on Arimadex?
 
sure
Study Shows That Arimidex Boosts Testosterone

Estrogen suppression in males: metabolic effects.
J Clin Endocrinol Metab 2000 Jul;85(7):2370-7 (ISSN: 0021-972X)
Mauras N; O'Brien KO; Klein KO; Hayes V [email protected].

We have shown that testosterone (T) deficiency per se is associated with
marked catabolic effects on protein, calcium metabolism, and body
composition in men independent of changes in GH or insulin-like growth
factor I production. It is not clear,,however, whether estrogens have a
major role in whole body anabolism in males. We investigated the metabolic
effects of selective estrogen suppression in the male using a potent
aromatase inhibitor, Arimidex (Anastrozole). First, a dose-response study of
12 males (mean age, 16.1 +/- 0.3 yr) was conducted, and blood withdrawn at
baseline and after 10 days of oral Arimidex given as two different doses
(either 0.5 or 1 mg) in random order with a 14-day washout in between. A
sensitive estradiol (E2) assay showed an approximately 50% decrease in E2
concentrations with either of the two doses; hence, a 1-mg dose was selected
for other studies. Subsequently, eight males (aged 15-22 yr; four adults and
four late pubertal) had isotopic infusions of [(13)C]leucine and
(42)Ca/(44)Ca, indirect calorimetry, dual energy x-ray absorptiometry,
isokinetic dynamometry, and growth factors measurements performed
before and after 10 weeks of daily doses of Arimidex. Contrary to the effects of T
withdrawal, there were no significant changes in body composition (body mass
index, fat mass, and fat-free mass) after estrogen suppression or in rates
of protein synthesis or degradation; carbohydrate, lipid, or protein
oxidation; muscle strength; calcium kinetics; or bone growth factors
concentrations. However, E2 concentrations decreased 48% (P = 0.006), with
no significant change in mean and peak GH concentrations, but with an 18%
decrease in plasma insulin-like growth factor I concentrations.
There was a
58% increase in serum Testosterone (P = 0.0001), sex hormone-binding globulin did not
change, whereas LH and FSH concentrations increased (P < 0.02, both). Serum
bone markers, osteocalcin and bone alkaline phosphatase concentrations, and
rates of bone calcium deposition and resorption did not change. In
conclusion, these data suggest that in the male 1) estrogens do not
contribute significantly to the changes in body composition and protein
synthesis observed with changing androgen levels; 2) estrogen is a main
regulator of the gonadal-pituitary feedback for the gonadotropin axis; and
3) this level of aromatase inhibition does not negatively impact either
kinetically measured rates of bone calcium turnover or indirect markers of
bone calcium turnover, at least in the short term. Further studies will
provide valuable information on whether timed aromatase inhibition can be
useful in increasing the height potential of pubertal boys with profound
growth retardation without the confounding negative effects of gonadal
androgen suppression.
 
Awesome info... These are the type of posts we need more of.
 
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