When your LH decreases to very low levels while on AS, Leydig cell LH receptor downregulates, & Leydig cell volume decreases which causes a decrease of testosterone-secreting capacity....
If you use Human Chorionic Gonadotropin (HCG) while on you will maintain Leydig cell volume & testosterone-secreting capacity...
Estrogen increase is only an issue when higher dosages are used since Human Chorionic Gonadotropin (HCG) stimulates testicular aromatase, that's why low dosages (300-500 IU) are recommended since they'll give you a better test/estradiol ratio...
Aromatase inhibitors do affect testicular aromatase & can prevent estradiol increase...
In this abstract 3000 IU of Human Chorionic Gonadotropin (HCG) was used, fourfold increase of estradiol was noticed while test was only doubled...
A study in which several consecutive Human Chorionic Gonadotropin (HCG) injections were administered was posted earlier (The initial E2 peak was absent in the divided dose protocol and the E2/T ratio only marginally increased)..
Endocrinol Jpn 1975 Aug;22(4):287-96 Related Articles, Links
Plasma estradiol concentrations and effect of Human Chorionic Gonadotropin (HCG) on plasma estradiol and testosterone in normal subjects and patients with endocrine disorders
...In the study of stimulation with human chorionic gonadotropin ( Human Chorionic Gonadotropin (HCG) ), 3,000 IU daily for three days in ten normal men, the peripheral concentrations of estradiol showed maximum and fourfold increases 24 hours after the 1st injection of Human Chorionic Gonadotropin ( Human Chorionic Gonadotropin (HCG) ). The testosterone levels, on the other hand, increased stepwise and reached a maximum of about two times preinjection levels 24 hours after the 3rd injection.
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Human Chorionic Gonadotropin (HCG) + aromatase inhibitor:
A study on testicular aromatase activity--spermatogenic damage in high testicular E2 models of rat]
Akiyama H.
Department of Urology, Okayama University Medical School.
(BACKGROUND): In order to study the influence of testicular estrogen concentration on spermatogenesis, we conducted the following experiments. (METHODS): Eight-week-old male Sprague-Dawley rats were used and two kinds of experiments were prepared. In experiment one (intraperitoneal injection), five groups were set up: control (saline solution), estradiol (E2), human chorionic gonadotropin (hCG), aromatase inhibitor (A.I.) and hCG+A.I. group. In experiment two (intratesticular injection), two groups were set up: control (saline solution) and E2 microcrystal suspension (Emcs) group. The experimental period was 28 days. At sacrifice, we evaluated the concentrations of serum testosterone (T) and E2, testicular T and E2, testicular aromatase activity and the seminiferous tubular diameter. (RESULTS): Exp. 1: In the hCG group, the rate of testicular aromatase activity and testicular E2 level were higher and the diameter of seminiferous tubules was smaller than in the control group. However, these changes were not observed in the hCG+A.I. group. Exp. 2: In the Emcs group, testicular E2 level showed an increase without elevation of serum E2 level, and the diameter of seminiferous tubules was atrophic. (CONCLUSION): It was suggested that the increase of the rate of testicular aromatase activity and the following elevation of testicular E2 level is possibly one of the causes of male infertility.
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T-E implant + LH treatment maintains the capacity of testes to secrete testosterone...
Effect of luteinizing hormone on Leydig cell structure and testosterone secretion.
Ewing LL, Wing TY, Cochran RC, Kromann N, Zirkin BR.
Hypophysectomy or sc implantation of testosterone-estradiol 17 beta (T-E) filled polydimethylsiloxane capsules for 5 days caused a dramatic reduction in testosterone secretion when testes subsequently were perfused in vitro. The diminution in testosterone-secreting capacity of testes from T-E treated rats was coupled closely with reductions in the membrane surface areas of Leydig cell cytoplasmic organelles, particularly those of the smooth endoplasmic reticulum. Simultaneous treatment of T-E implanted rats with LH (12 micrograms/day), but not with FSH, PRL, TSH, or GH, maintained both the Leydig-cell cytoplasmic membranes and the capacity of testes to secrete testosterone in vitro. Testosterone secretion by testes from hypophysectomized rats treated simultaneously with T-E plus LH was identical to that in control rats. Therefore, T-E did not inhibit directly the Leydig cell steroidogenic apparatus...