Human testicular secretion with increasing age

Serio, Mario; Gonnelli, P; Borrelli, D; Pampaloni, Alessio; Fiorelli, G; Calabresi, E.; Forti, Gianni; Pazzagli, Mario; Mannelli, Massimo; Baroni, A.; Giannotti, P.; Giusti, G.

doi:10.1016/0022-4731(79)90026-8

Cited by 27 publications

(8 citation statements)

References 21 publications

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“…Decreased concentrations of testosterone in peripheral and spermatic venous blood compared with the concentrations found in younger adult males have been reported in elderly men [ 14,16,20,31 1. This may be due to a primary testicular insufficiency as well as the presence of a hypothalamic-pituitary disorder of gonadotropin secretion associated with the aging process [31].…”

Section: Discussionmentioning

confidence: 92%

“…High intratesticular concentrations of testosterone are necessary for normal spermatogenesis [24] . Many authors have reported that testicular testosterone secretion decreases with age [14,17,20,301, while others have refuted this theory [9]. LH seems to be the most important regulator of testicular steroid production through the induction or activation of enzymes responsible for androgen biosynthesis [29] .…”

Section: Introductionmentioning

confidence: 99%

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In Vitro Conversion of³H-Pregnenolone by Human Testicular Tissue from Fetal Age to Senescence

Hammar¹,

Ahlstrand²,

Berg³

et al. 1984

Archives of Andrology

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The in vitro conversion of pregnenolone was studied in testicular tissue specimens from 6 fetuses, 3 prepubertal boys with indescended testes, 5 normal adult men, and 12 elderly males with prostatic carcinoma. Adult testicular tissue converted pregnenolone to testosterone mainly along the A5 metabolic pathway. Steroid intermediates that were converted from pregnenolone to A4 metabolites prior to the rate limiting C17-20 lyase step were "trapped" as 17a-hydroxyprogesterone. The conversion patterns in testicular tissue from fetuses were similar to those in testicular tissue from adults and elderly men. In prepubertal testicular tissue, however, a significantly lower conversion was observed, mediated by the enzymes 3phydroxysteroid dehydrogenase/isomerase and 17a-hydroxylase. The conversion mediated by 17whydroxylase was significantly lower in testicular tissue from the elderly males than from younger adults, suggesting a relative steroidogenic insufficiency in the elderly males. Testicular tissue from an anencephalic fetus produced testosterone and steroid intermediates in vitro, although to a lesser extent than in testicular tissue from other fetuses. The enzymes 30-hydroxysteroid dehydrogenase/isomerase and 17~-hydroxylase appeared to be under gonadotropic control.Human testis; Steroid conversion; Pregnenolone; Testosterone; 3P-hydroxysteroid dehydrogenase; 1 7a-hydroxylase.

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Section: Discussionmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

In Vitro Conversion of³H-Pregnenolone by Human Testicular Tissue from Fetal Age to Senescence

Hammar¹,

Ahlstrand²,

Berg³

et al. 1984

Archives of Andrology

View full text Add to dashboard Cite

show abstract

“…Many authors have reported decreased peripheral and spermatic venous testosterone concentrations in elderly men (Lewis et al -1976;Nieschlag -1979;Serio et al -1979;Mastragiacomi et al -1982). Testosterone secretion, however, was found to be preserved in a group of healthy, elderly men (Harman and Tsitouras -1980).…”

Section: Discussionmentioning

confidence: 99%

“…Based on measurements in peripheral or spermatic venous blood, testicular testosterone secretion has been reported to decrease with age (Lewis et al -1976;Nieschlag -1979;Serio et al -1979;Mastragiacomi et al -1982). It has also been reported that the circadian variation of the testosterone secretion found in normal young males was markedly attenuated or even absent in healthy elderly men (Bremner et al -1983).…”

Section: Introductionmentioning

confidence: 99%

Impaired in vitro Testicular Endocrine Function in Elderly Men

Hammar

2009

Andrologia

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Measurements of testosterone concentrations in peripheral and spermatic venous blood have yielded conflicting results concerning testosterone production in elderly men. To further elucidate the testicular endocrine capacity during aging, peripheral serum hormone levels and the in vitro conversion of progesterone and pregnenolone in histopathologically normal testicular tissue have been investigated in 22 elderly men and 28 younger adult males. The conversion mediated by 30-hydroxysteroid-dehydrogenase and 17a-hydroxylase was significantly higher (p < 0.05 and p < 0.01 respectively) in testicular tissue from the younger adult men, than in testicular tissue from elderly men. Since serum LH levels were significantly higher (p < 0.01) and serum testosterone levels were significantly lower (p < 0.01) in the elderly men, these data indicate that there was a primary endocrine impairment at the testicular level in the elderly men. In vitro-Beeintrachtigung der endokrinen Hodenfunktion beim alteren MannZusammenfassung: Messungen der Testosteronkonzentration im peripheren Blut und im Venenblut der V. spermatica haben widerspriichliche Resultate hinsichtlich der Testosteronproduktion des alteren Mannes ergeben. Daher wurden zur weiteren Auildarung der endokrinen Kapazitat des Hodens im Alter bei 22 dteren Mannern und bei 28 jiingeren Erwachsenen (18-49 Jahre alt) die peripheren Serum-Hormon-Werte als auch die in vitro-Conversion von Progesteron und Pregnenolon bei histologisch normalem Hodengewebe untersucht. Die Conversionvermittelt durch 30-Hydroxysteroid-dehydrogenase und 17a-Hydroxylasewar signifiant hoher (p < 0,05 bzw. p < 0,Ol) im Hodengewebe von jiingeren erwachsenen Mannern als im Hodengewebe von dteren Mannern (60-83 Jahre).Da die Serum-LH-Werte signifikant hoher (p < 0,Ol) und die Serum-Testosteron-Werte signifikant niedriger (p < 0,Ol) bei alteren Mannern waren, bedeuten diese Daten, dat3 es sich bei den alteren Mannern um eine primare endokrine Beeintrachtigung der Hodenfunktion handelt.

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“…In collaboration with some surgeons we used these methods to measure the concentration of testosterone and other steroids in the spermatic venous blood drawn during surgery for undescended testis and inguinal hernia in pre‐pubertal boys and adult men, respectively. In summary after my degree in Medicine my work was mainly dedicated to assay methods and then to the study of Leydig cell function of the human testis (Serio et al ., ). In 1980 Mario Serio was appointed Full Professor of Andrology in the University of Sassari in Sardinia and three years later he moved to Florence.…”

Section: Measuring Hormones In An Underground Laboratory: Leydig Cellmentioning

confidence: 97%

Human testicular secretion with increasing age

Cited by 27 publications

References 21 publications

In Vitro Conversion of³H-Pregnenolone by Human Testicular Tissue from Fetal Age to Senescence

In Vitro Conversion of³H-Pregnenolone by Human Testicular Tissue from Fetal Age to Senescence

Impaired in vitro Testicular Endocrine Function in Elderly Men

Lessons learned in andrology: from endocrinology to andrology and backwards: the round trip of a clinician

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Human testicular secretion with increasing age

Cited by 27 publications

References 21 publications

In Vitro Conversion of3H-Pregnenolone by Human Testicular Tissue from Fetal Age to Senescence

In Vitro Conversion of3H-Pregnenolone by Human Testicular Tissue from Fetal Age to Senescence

Impaired in vitro Testicular Endocrine Function in Elderly Men

Lessons learned in andrology: from endocrinology to andrology and backwards: the round trip of a clinician

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In Vitro Conversion of³H-Pregnenolone by Human Testicular Tissue from Fetal Age to Senescence

In Vitro Conversion of³H-Pregnenolone by Human Testicular Tissue from Fetal Age to Senescence