Endocrine and local testicular regulation

2011 ◽  
pp. 1347-1353
Author(s):  
Ilpo Huhtaniemi
Keyword(s):  
Growth Factors ◽  
Luteinizing Hormone ◽  
Leydig Cell ◽  
Follicle Stimulating Hormone ◽  
Regulatory System ◽  
The Other ◽  
Seminiferous Tubules ◽  
Testicular Function ◽  
Cell Product ◽  
Stimulating Hormone

The testis has two functions, androgen production and spermatogenesis, and a key role in their regulation is played by the two pituitary gonadotropins, luteinizing hormone and follicle-stimulating hormone (FSH). Other hormones and growth factors also influence testicular function, often by modulating the gonadotropin effects. Moreover, a plethora of local paracrine and autocrine signals within the testis are known. The main testicular hormone, testosterone, a Leydig cell product, regulates spermatogenesis in seminiferous tubules in paracrine fashion. The other functions of testosterone are endocrine, occurring outside the testis. This chapter summarizes the main hormonal regulatory system of the testis, the hypothalamic–pituitary–testicular axis, and how its effects are modulated by other extratesticular hormones and local testicular factors.

Studies on Spermatogenesis in Rats. III. Effects of Hormonal Treatment on Differentiation Kinetics of the Spermatogenic Cycle in Regressed Hypophysectomized Rats

1971 ◽  
Vol 49 (7) ◽  
pp. 768-775 ◽  
Author(s):  
V. L. W. Go ◽  
R. G. Vernon ◽  
I. B. Fritz
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Hormonal Treatment ◽  
Testicular Function ◽  
Carnitine Acetyltransferase ◽  
Hormonal Replacement ◽  
Hypophysectomized Rats ◽  
Kinetics Of ◽  
Stimulating Hormone

The general hormonal requirements for the restoration of spermatogenesis in regressed hypophysectomized rats were investigated. With the aid of the Staput fractionation technique, it was established that thymidine-3H was readily incorporated into spermatogonia and resting spermatocytes. Labeled cells did not progress to form appreciable numbers of primary spermatocytes or spermatids in the absence of hormonal replacement. The inhibition of formation of pachytene primary spermatocytes in hypophysectomized rats was overcome by administration of follicle-stimulating hormone (FSH), luteinizing hormone (LH), or testosterone, but a combination of either FSH plus LH, or FSH plus testosterone, was required for the progression of pachytene primary spermatocytes to spermatids and spermatozoa. Carnitine acetyltransferase (CAT) measurements in testes from various groups of animals provided ancillary evidence consistent with the conclusion that either FSH, LH, or testosterone was required for the normal restoration of pachytene-diplotene spermatocyte formation. However, one or more additional blocks in spermatogenesis existed in hypophysectomized animals, since elevation of depressed testicular CAT levels in hypophysectomized rats to normal levels required FSH plus LH, or FSH plus testosterone. Cortisone and thyroxin treatment had no measurable effects on testicular function in hypophysectomized rats.

OESTROGEN SYNTHESIS IN RAT OVARIES IN VITRO: EFFECTS OF ENDOGENOUS AND EXOGENOUS GONADOTROPHINS

1972 ◽  
Vol 53 (3) ◽  
pp. 397-406 ◽  
Author(s):  
BRENDA ROBINSON ◽  
R. E. OAKEY
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Oestrous Cycle ◽  
The Other ◽  
Ovarian Vein ◽  
Hormone Activity ◽  
In Vitro Effects ◽  
Stimulating Hormone

SUMMARY The rate of synthesis of [14C]oestrone and [14C]oestradiol-17β from [14C]testosterone in vitro by ovaries from rats at different stages of the oestrous cycle was measured. The rate of [14C]oestrogen synthesis was highest in ovaries taken from rats in pro-oestrus and lowest in ovaries taken from rats early in the dioestrous phase of the cycle. Rates of synthesis in ovaries obtained from rats in the late dioestrous stage were intermediate between the rates of the other groups. The rates of [14C]oestrogen synthesis at these periods of the cycle paralleled the concentrations of oestrogens in ovarian vein plasma reported by other authors. Gonadotrophin preparations with either luteinizing hormone activity or both follicle-stimulating hormone and luteinizing hormone activities had no effect on [14C]oestrogen synthesis by rat ovaries in vitro at any of these stages of the oestrous cycle.

Pharmacokinetics of gonadotropin therapy

1996 ◽  
Vol 5 (1) ◽  
pp. 13-35 ◽  
Author(s):  
Tally Levy ◽  
Zion Ben-Rafael
Keyword(s):  
Growth Factors ◽  
Luteinizing Hormone ◽  
Crucial Role ◽  
Follicle Stimulating Hormone ◽  
Gonadotropin Releasing Hormone ◽  
Gonadal Steroids ◽  
Releasing Hormone ◽  
Gonadotropin Therapy ◽  
Stimulating Hormone

Ovulation is the result of an integrated action of the hypothalamus, pituitary and ovaries. During the process, gonadal steroids, peptides and growth factors are produced and influence the synthesis and release of gonadotropin-releasing hormone (GnRH), follicle stimulating hormone (FSH) and luteinizing hormone (LH). These latter compounds play a crucial role in folliculogenesis and are frequently used in the management of infertility.

THE EFFECTS OF SYNTHETIC GONADOTROPHIN RELEASING FACTOR ON THE RELEASE OF LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE FROM OVINE PITUITARY TISSUE IN VITRO

1973 ◽  
Vol 58 (3) ◽  
pp. 387-391 ◽  
Author(s):  
D. B. CRIGHTON
Keyword(s):  
Luteinizing Hormone ◽  
Incubation Medium ◽  
Synthetic Peptides ◽  
Follicle Stimulating Hormone ◽  
The Other ◽  
Pituitary Tissue ◽  
Incubation System ◽  
Stimulating Hormone

SUMMARY A synthetic decapeptide gonadotrophin releasing factor was tested for effects on the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) using an ovine pituitary incubation system. The effects of other synthetic peptides used at similar doses were studied. The synthetic decapeptide consistently provoked significant increases in the LH content of the incubation medium at doses equal to or in excess of 0·5 ng/flask (0·2 ng/ml medium). Significant increases in the FSH content of the incubation medium at doses equal to or in excess of 0·25 ng/flask (0·1 ng/ml medium) were observed. The other synthetic peptides failed to influence LH or FSH release in vitro even at a dose 20–40 times greater. The results demonstrate that the decapeptide releases both LH and FSH from sheep pituitary tissue, suggesting that it may play a role in the release of both hormones in vivo in the sheep.

EFFECTS OF PROLACTIN ON SPERMATOGENESIS IN HYPOPHYSECTOMIZED MICE

1971 ◽  
Vol 49 (2) ◽  
pp. 311-316 ◽  
Author(s):  
A. BARTKE
Keyword(s):  
Growth Hormone ◽  
Luteinizing Hormone ◽  
Leydig Cells ◽  
Testosterone Propionate ◽  
Follicle Stimulating Hormone ◽  
Seminiferous Tubules ◽  
Partial Restoration ◽  
Pachytene Spermatocytes ◽  
Stimulating Hormone

SUMMARY Hypophysectomized mice were treated daily for 28 days with 12 i.u. prolactin, 10 μg luteinizing hormone (LH), 10 μg LH plus 12 i.u. prolactin, 50 μg testosterone propionate (TP), or 50 μg TP plus 12 i.u. prolactin. The yield of spermatogenesis was studied quantitatively from the counts of spermatogonia, preleptotene and pachytene spermatocytes and spermatids in the seminiferous tubules at stage VII of spermatogenesis. Prolactin administered alone caused a small, but significant, increase in the yield of spermatogenesis. Treatment with a mixture of LH, follicle-stimulating hormone and growth hormone in amounts 1·5 times higher than those reported as contaminants of prolactin had similar effects. Injections of LH or TP caused partial restoration of spermatogenesis. The yield of spermatogenesis was significantly higher in animals given LH plus prolactin than in the animals given LH alone. Prolactin, however, did not augment the effects of TP on spermatogenesis. It is concluded that prolactin acts on the Leydig cells of the testis to increase their responsiveness to LH. More androgen appears to be produced under the influence of LH when prolactin is also present.

scholarly journals Genetic and sex hormone analysis of infertile men

2019 ◽  
Vol 48 (2) ◽  
pp. 030006051987589
Author(s):  
Xiaolei Xie ◽  
Xiaoyan Guo ◽  
Fuguang Li ◽  
Weihe Tan ◽  
Weiguo Yin ◽  
...  
Keyword(s):  
Luteinizing Hormone ◽  
Male Infertility ◽  
Follicle Stimulating Hormone ◽  
Study Groups ◽  
Sex Hormone ◽  
The Other ◽  
Serum Testosterone Level ◽  
Genetic Characteristics ◽  
Hormone Analysis ◽  
Stimulating Hormone

Objective Genetic defects and endocrine-related factors are the leading causes of male infertility. This study was performed to analyze the genetic characteristics and sex hormone levels in different types of male infertility. Methods A total of 423 men with infertility underwent genetic and sex hormone analysis at The Sixth Affiliated Hospital of Guangzhou Medical University. Results The incidences of abnormal karyotypes in patients with male infertility, azoospermia, and oligoasthenozoospermia were 6.94%, 22.40%, 15.09%, respectively. Among men with azoospermia, Klinefelter syndrome (47,XXY) was identified in 60.71% (17/28) of those with abnormal karyotypes. Additionally, the levels of follicle-stimulating hormone and human luteinizing hormone were significantly higher in men with azoospermia showing abnormal karyotypes than in men of the other study groups. The serum testosterone level in men with azoospermia showing abnormal karyotypes was lower than that in men of the other study groups. Conclusions Azoospermia is closely associated with chromosome abnormalities. The levels of testosterone, human luteinizing hormone, and follicle-stimulating hormone in men with azoospermia showing abnormal karyotypes provide a clinical reference for genetic counseling and assisted reproduction.

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