Age-Related Changes in the Metabolism of [3h]testosterone in Vitro by the Epididymis of the Immature Rat

Foldesy, Robin G.; Leathem, James H.

doi:10.1677/joe.0.0910043

Cited by 8 publications

(5 citation statements)

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“…DISCUSSION A previous study of in-vitro [3H]testosterone metabolism by the immature rat epididymis indicated that the same metabolites are formed as in adult tissue but in different proportions (Foldesy & Leathem, 1981a). The present results suggest that the effects of androgen withdrawal upon androgen metabolism by the immature rat epididymis may differ also from those observed in adults.…”

Section: Resultssupporting

confidence: 50%

“…Tissue incubations and analysis of radioactive metabolites The incubation procedure, and the analysis and identification of radioactive metabolites are presented in a companion study (Foldesy & Leathem, 1981a). Briefly, excised epididymides were severed at the mid-corpus region to give caput and cauda segments which were then minced and incubated separately in 5 ml Krebs-Henseleit bicarbonate buffer with 5ng…”

Section: Animal Treatmentsmentioning

confidence: 99%

“…The metabolism itself is an androgen-responsive process (Djoseland, 1976) since castration results in a decreased activity of both 5a-reductase, the enzyme which converts testosterone to 17/?-hydroxy-5a-androstan-3-one (5a-dihydrotestosterone; DHT), and 3a-hydroxysteroid oxidoreductase, the enzyme which catalyses the conversion of DHT to 5a-androstane-3a,17/?-diol (Robaire, Ewing, Zirkin & Irby, 1977;Danzo & Eller, 1980). The epididymis of the immature rat also possesses a competent androgen-metabolizing system (Scheer & Robaire, 1980) but the quantities of individual metabolites produced, most notably 5a-androstane-3a,17/?-diol and 5a-androstane-3,17-dione (5a-androstanedione), differ significantly from those of adult epididymides (Foldesy & Leathem, 1981a). This correlates with both the immature histological appearance (Reid, 1959;Sun & Flickinger, 1979) and lower DHT concentration of the peripubertal rat epididymis (Aafjes & Vreeburg, 1972;Podestà, Calandra, Rivarola & Blaquier, 1975;Foldesy & Leathem, 19816).…”

Section: Introductionmentioning

confidence: 99%

“…Results are expressed as percent of those androgens isolated and analysed. Values are means + s.E.control animals fromFoldesy & Leathem (1981a). t = 2-5 mg testosterone/kg body wt per day.I Epididymis on the operated side.…”

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Effects of Short-Term Bilateral and Unilateral Castration and Androgen Replacement on the Metabolism of [3h]testosterone in Vitro by the Epididymis of the Immature Rat

Foldesy¹,

Leathem²

1981

Journal of Endocrinology

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The in-vitro metabolism of [3H]testosterone by the epididymis of the pubertal rat (55 days of age) has been examined after short-term bilateral and unilateral castration and androgen replacement. Bilateral castration did not decrease the metabolism of [3H]testosterone, but did result in a decline in the proportion of 5\g=a\-dihydrotestosterone produced and an increase in that of 5\g=a\-androstane-3\g=a\,17\g=b\-diol, androsterone and 5\g=a\-androstane-3,17-dione.Changes in metabolism occurred in the caput within 2 days after surgery, but not until 5 days after surgery in the cauda epididymidis. Daily testosterone treatment, which maintained prostatic growth in bilaterally castrated animals, did not restore normal androgen metabolism and increased further the production of androsterone and 5\g=a\-androstanedione by the cauda. In unilaterally castrated animals, androgen metabolism in epididymal tissue from the operated side was normal in the cauda but was indistinguishable in the caput from that of bilaterally castrated rats. These results indicate that (a) androgen metabolism by the caput, compared to that by the cauda, responds more quickly to androgen withdrawal and (b) that in the short term, normal androgen metabolism by the caput, but not the cauda, is dependent upon the presence of the ipsilateral testis. Furthermore, testosterone alone proved an inadequate replacement for bilateral castration which implies that the pubertal rat testis secretes additional compounds which are essential for normal function of the epididymis.

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Section: Resultssupporting

confidence: 50%

Section: Animal Treatmentsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

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Effects of Short-Term Bilateral and Unilateral Castration and Androgen Replacement on the Metabolism of [3h]testosterone in Vitro by the Epididymis of the Immature Rat

Foldesy¹,

Leathem²

1981

Journal of Endocrinology

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“…In older men, a decrease in zinc removal from the tail outer dense fiber during epididymal maturation was correlated with a decrease in motility. Furthermore, reports have indicated an age-related decrease in biochemical parameters including testosterone, fructose and accessory gland functions resulting in the decline in sperm motility with age [22][23][24] .…”

Section: Discussionmentioning

confidence: 99%

Male Age and Sperm Necrosis in Assisted Reproductive Technologies

et al. 2007

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Introduction: Sperm apoptosis is well characterized but studies on the effect of male age and necrozoospermia are lacking. The objectives were: (a) to analyze percentages of apoptotic and necrotic sperm in ejaculates, and (b) to compare the results between younger and older age groups. Materials and Methods: Routine semen analyses were carried out (n = 189 males) and sperm cells were analyzed by dual fluorescence assay Hoechst 33342 and propidium iodide, and the acridine orange test. Results: The percentage of necrotic sperm in the ejaculate increased by 22% for males aged over 35. There was a positive correlation between age and necrosis (R = 0.30). Sperm apoptosis increased by 17% in males aged 45 and older. The population of DNA intact sperm declined in males aged 40 and over (R = –0.21). There were no age-related changes in strict normal morphology, sperm concentration and semen volume. A decrease in rapid progressive motility was correlated (R = –0.24) with male age and was significant after age 35. Conclusions: The study demonstrated increased necrosis, DNA damage and apoptosis while rapid progression and total motility declined with advancing age in the male beginning as early as age 35. The order of the observed changes was sequential, suggesting the involvement of different pathways in sperm necrosis after age 40.

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Effect of neonatal estrogenization on testosterone metabolism in the prostate and in the epididymis of the rat

Pinilla

Cocconi

Zoppi

et al. 1989

Journal of Steroid Biochemistry

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Age-Related Changes in the Metabolism of [3h]testosterone in Vitro by the Epididymis of the Immature Rat

Cited by 8 publications

References 30 publications

Effects of Short-Term Bilateral and Unilateral Castration and Androgen Replacement on the Metabolism of [3h]testosterone in Vitro by the Epididymis of the Immature Rat

Effects of Short-Term Bilateral and Unilateral Castration and Androgen Replacement on the Metabolism of [3h]testosterone in Vitro by the Epididymis of the Immature Rat

Male Age and Sperm Necrosis in Assisted Reproductive Technologies

Effect of neonatal estrogenization on testosterone metabolism in the prostate and in the epididymis of the rat

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