The Effect of Estradiol on Testicular Testosterone Biosynthesis

Kalla, N.R.; Nisula, Bruce C.; Menard, Raymond H.; Loriaux, D. Lynn

doi:10.1210/endo-106-1-35

Cited by 142 publications

(47 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Administration of E 2 has been found to inhibit both the hypothalamus and pituitary of male animals [8], and the testicular function in the bull [24] and the dog [27] is suppressed by E 2 injection. Mattheeuws and Comhaire [18] found that the plasma E 2 levels in the spermatic vein of the abdominal cryptorchid testis of dogs with congenital cryptorchidism are higher than in normal dogs, and an increase in E 2 production in the artificially cryptorchid testis has been observed in the rat [3].…”

Section: Discussionmentioning

confidence: 99%

Function of Contralateral Testis after Artificial Unilateral Cryptorchidism in Dogs

Kawakami

Hori

Tsutsui

1999

The Journal of Veterinary Medical Science

View full text Add to dashboard Cite

ABSTRACT. The effects of a cryptorchid testis on the contralateral testis were investigated after artificially producing unilateral cryptorchidism in 8 beagle dogs. Bilateral testicular biopsy and collection of spermatic vein blood and peripheral vein blood were performed at the time of the operation to produce the cryptorchidism and 52 weeks later. The testicular tissue was used for histological examination by light microscopy and measurement of the testicular transferrin (Tf) concentration by enzyme immunoassay. Plasma testosterone (T), estradiol-17β (E 2 ), and luteinizing hormone (LH) levels were measured by radioimmunoassay. Semen was collected weekly and its quality was examined. No spermatogenesis was observed in the cryptorchid testes at 52 weeks after the operation, and the number of germ cells in the contralateral testes had decreased but the number of Sertoli cells did not change. The Tf concentration in both testes had also decreased. The mean total number of sperm between 48 and 52 weeks after the operation (194 × 10 6 ) was less than half the number before the operation (510 × 10 6 ). Mean spermatic vein plasma T levels (51 ng/ml) in the cryptorchid testes 52 weeks after the cryptorchid operation were significantly lower than before the operation (91 ng/ml; P<0.05). By contrast, spermatic vein plasma E 2 levels (80 pg/ml) were significantly higher than the values before the operation (51 pg/ml P<0.05). The peripheral plasma LH levels decreased. These findings indicate that a large quantity of E 2 secreted by the cryptorchid testis inhibits the endocrine and spermatogenic functions of the contralateral testis in the dog. In particular, it is assumed that dysfunction of the contralateral testis is associated with Sertoli cell dysfunction suggested by the low Tf concentration.-KEY WORDS: artificial cryptorchidism, canine, estrogen.

show abstract

Section: Discussionmentioning

confidence: 99%

Function of Contralateral Testis after Artificial Unilateral Cryptorchidism in Dogs

Kawakami

Hori

Tsutsui

1999

The Journal of Veterinary Medical Science

View full text Add to dashboard Cite

show abstract

“…High testicular Tf concentrations were found in the 4 azoospermic dogs, suggesting on abnormally enhanced function of Sertoli cells, which are known to produce high levels of E 2 [6,19], and to control Leydig cell functions by a paracrine effect [7,24]. High concentration of plasma E 2 might also inhibit T secretion from the testis [11], possibly inducing apoptotic death of germ cells [5]. After E 2 injection, spermatids and spermatozoa were reported to disappear in the seminiferous tubules of bulls [18] and atrophy was induced in the testes of dogs [10].…”

mentioning

confidence: 98%

Azoospermia of Dogs with Apoptotic Germ Cells and Leydig Cells

Kawakami

Hori

Tsutsui

2000

The Journal of Veterinary Medical Science

View full text Add to dashboard Cite

ABSTRACT. Apoptotic cell death in the testes of 4 dogs with azoospermia was examined. Blood plasma luteinizing hormone (LH), testosterone (T), and estradiol-17β (E 2 ) concentrations, and testicular transferrin (Tf) concentration as a marker of Sertoli cell function were measured in the 4 azoospermic dogs and in 5 normal dogs. The spermatids in 2 of the 4 azoospermic dogs and the Leydig cells in 3 of them exhibited apoptotic cell death. Mean LH, E 2 , and Tf concentrations in the 4 azoospermic dogs were significantly higher than in the normal dogs (P<0.01). These findings suggested that the azoospermia in all 4 dogs might has been caused by abnormal functions of Sertoli cells as well as Leydig cells.-KEY WORDS: apoptosis, azoospermia, canine.

show abstract

“…The stimulation of 3β-HSD activity may increase the synthesis of progesterone as suggested in studies using slices of testis taken from estrogen -treated rats. 17 The quantitative analysis of seminiferous tubules at stage VII of the cycle revealed that melatonin treatment reduced the number of spermatogonia, preleptotene spermatocytes and spermatids. Theoretically the pachytene spermatocytes: Spermatids ratio should be 1:4 13 in our control ratio is 1:3.52 i.e.…”

Section: Discussionmentioning

confidence: 99%

Effect of gonadotropins and alpha 2u-globulin on testicular steroidogenesis and spermatogenesis in melatonin-treated rats

Biswas

Nm²,

Mandal³

2012

J Coll Med Sci-Nepal

View full text Add to dashboard Cite

IntroductionA sex-dependent urinary protein, alpha 2u-globulin is synthesized in the liver and due to its small molecular size it is cleared by the kidneys in the adult male rats. 1,2 Sexually mature male rats show diurnal rhythm of alpha 2u-globulin synthesis.3 Similar diurnal rhythm also occurs in melatonin synthesis from the pineal gland in rats. 4 On the other hand melatonin treatment causes a substantial decrease in FSH together with testicular atrophy. 5 While perfusion of the third cerebroventricle with melatonin lowers the plasma concentration of both FSH and LH in the adult rats. 6 Melatonin treatment also decreases serum level of gonadotropins and alpha 2u-globulin along with the inhibition of testicular activity in the adult rats. 7The purpose of the present investigation was to determine whether external administration of FSH, LH or alpha 2u-globulin can prevent testicular degeneration in melatonin-treated rats. Materials and methodsAnimal-Adult male rats of Sprague Dawley (Rattus norvegcus) strain weighing 150-200g were used in this experiment. A standard laboratory chow and water were available ad-libitum. Preparation of alpha 2u-globulinAlpha 2u globulin was isolated from male rat urine according to the method of Roy, Neuhaus and AbstractAdministration of melatonin (400µg/100g bd.wt.) for 14 days caused a fall in weights of the testes and accessory sex organs and testicular 17β-hydroxysteroid dehydrogenase (17β-HSD) but rise in 3β-hydroxysteroid dehydrogenase (3β-HSD) activity, decreased spermatogenesis, serum level of gonadotropins, testosterone and alpha 2u-globulin, The animals treated with melatonin when received gonadotropins or alpha 2u-globulin for the last seven days reversed the weight of testis and accessory sex organs, 3β-HSD, 17β-HSD activities, serum level of gonadotropins, testosterone and alpha 2u-globulin when compared with melatonin-treated rats. It is concluded that alpha 2u-globulin prevents testicular degeneration in melatonin-treated rats by stimulating the synthesis of gonadotropins.

show abstract

The Effect of Estradiol on Testicular Testosterone Biosynthesis

Cited by 142 publications

References 35 publications

Function of Contralateral Testis after Artificial Unilateral Cryptorchidism in Dogs

Function of Contralateral Testis after Artificial Unilateral Cryptorchidism in Dogs

Azoospermia of Dogs with Apoptotic Germ Cells and Leydig Cells

Effect of gonadotropins and alpha 2u-globulin on testicular steroidogenesis and spermatogenesis in melatonin-treated rats

Contact Info

Product

Resources

About