Serum Testosterone Concentrations in Embryonic and Fetal Pigs During Sexual Differentiation

Ford, J. J.; Christenson, R. K.; Maurer, R. R.

doi:10.1095/biolreprod23.3.583

Cited by 71 publications

(39 citation statements)

References 25 publications

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“…Thereafter, testosterone concentrations decrease and remain low during further fetal development (Ford et al 1980). Another considerable rise was not demonstrated before an age of 4-6 weeks postnatally (Schwarzenberger et al 1993).…”

Section: Introductionmentioning

confidence: 92%

“…In consequence, their formation is highly correlated with androgens and occurs exclusively in Leydig cells of mature boars . Steroid formation in testes of pig fetuses revealed a first rise of androgen biosynthesis around 30 days postcoitum (Ford et al 1980). Mesenchymal Leydig cells were identified as the primary source of testosterone at that stage of development (Pelliniemi 1975, Pelliniemi et al 1979.…”

Section: Introductionmentioning

confidence: 99%

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Changes of testicular aromatase expression during fetal development in male pigs (sus scrofa)

Haeussler

Wagner²,

Welter³

et al. 2007

Reproduction

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Male pig fetuses secrete considerable amounts of estrogens, but the location of aromatase activity within the fetal testis is not known. The location of aromatase expression was investigated by immunocytochemistry in fetal testes from week 6 (nZ5), weeks 10, 13, and 15 (each: nZ6) of gestation and additionally in neonates (nZ4). Blood was sampled from the umbilical artery of fetuses and jugular vein of neonates. Histological evaluation of testes involved morphological criteria and counting of Leydig cells, Sertoli cells, and gonocytes. Aromatase activity was localized immunocytochemically and quantified by the percentage of positive stained cells within the same cell type. Aromatase expression was further characterized by quantitative RT-PCR. Concentrations of estrogens, testosterone, FSH, and LH were measured in blood plasma. Total estrogens increased from week 10 to a maximum of 31.03 nmol/l in week 15. Increased testosterone concentrations were only measured at week 6 and were paralleled by slightly elevated estrogens. Thereafter, testosterone dropped and was low throughout. The increase of estrogens was not paralleled by a similar increase of FSH and LH but was related to the increase of the total number of Leydig cells. This increase was also found for mRNA expression. Both Leydig cells and gonocytes were identified as contributors to estrogen formation. Gonocytes were the main source of aromatase at week 10, when gene expression by Leydig cells is low due to the preparation of a wave of Leydig cell mitosis. Reproduction (2007) 133 323-330

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Section: Introductionmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Changes of testicular aromatase expression during fetal development in male pigs (sus scrofa)

Haeussler

Wagner²,

Welter³

et al. 2007

Reproduction

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“…Mullerian duct regression, which was not evaluated in this study. Similarly, elevated P450 c17 in MS boars may be associated with increased testosterone synthesis and secretion from Leydig cells (Moon et al 1973, Ford et al 1980. Potential association of differential production of MIS and P450 c17 with cell function, and relationship to future reproductive characteristics in these two diverse breeds of pigs remain to be elucidated.…”

Section: Discussionmentioning

confidence: 99%

Expression levels of Mullerian-inhibiting substance, GATA4 and 17alpha-hydroxylase/17,20-lyase cytochrome P450 during embryonic gonadal development in two diverse breeds of swine

McCoard

Wise²,

Ford³

2002

Journal of Endocrinology

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Sexual differentiation and early embryonic/fetal gonad development is a tightly regulated process controlled by numerous endocrine and molecular signals. These signals ensure appropriate structural organization and subsequent development of gonads and accessory organs. Substantial differences exist in adult reproductive characteristics in Meishan (MS) and White Composite (WC) pig breeds. This study compared the timing of embryonic sexual differentiation in MS and WC pigs. Embryos/fetuses were evaluated on 26, 28, 30, 35, 40 and 50 days postcoitum (dpc). Gonadal differentiation was based on morphological criteria and on localization of GATA4, Mullerianinhibiting substance (MIS) and 17 -hydroxylase/17,20-lyase cytochrome P450 (P450 c17 ). The timing of testicular cord formation and functional differentiation of Sertoli and Leydig cells were similar between breeds. Levels of GATA4, MIS and P450 c17 proteins increased with advancing gestation, with greater levels of MIS and P450 c17 in testes of MS compared with WC embryos. Organization of ovarian medullary cords and formation of egg nests was evident at similar ages in both breeds; however, a greater number of MS compared with WC embryos exhibited signs of ovarian differentiation at 30 dpc. In summary, despite breed differences in MIS and P450 c17 levels in the testis, which may be related to Sertoli and Leydig cell function, the timing of testicular differentiation did not differ between breeds and is unlikely to impact reproductive performance in adult boars. In contrast, female MS embryos exhibited advanced ovarian differentiation compared with WC embryos which may be related to the earlier reproductive maturity observed in this breed.

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“…3) (Allen, 1904;Whitehead, 1904; (Belt & Cavazos, 1967;Aquas, 1981;van Vorstenbosch et al, 1984) which coincides with increased testicular steroidogenesis (Raeside & Sigman, 1975;Colenbrander et al, 1978;Ford et al, 1980;Herrera et al, 1983;Lunstra et al, 1986 (Russo & Rosas, 1971;Mancini et al, 1963;Moon & Hardy, 1973). Changes in the number of Leydig cells of boars have been reported to be indirectly related to the number of mesenchymal cells (Moon & Hardy, 1973).…”

Section: Methodsmentioning

confidence: 99%

“…However, it is possible that elevated plasma FSH and GH concentrations in Group-HC boars may have induced Leydig cell proliferation by altering the intratesticular concentration of Sm-C/IGF-I which was then responsible for the cytodifferentiation of existing mesenchymal cells into Leydig cells. However, it is also possible that GH acts via the liver, since in rats a pubertal increase in Sm-C/IGF-I has been shown to be at least partly independent of the gonads (Handelsman et al, 1987 (Belt & Cavazos, 1967;Aquas, 1981;Ewing & Zirkin, 1983;van Vorstenbosch et al, 1984) and directly coincides with changes in testicu¬ lar steroid production (Raeside & Sigman, 1975;Colenbrander et al, 1978;Ford et al, 1980;Herrera et al, 1983). Cytoplasmic volume of Leydig cells of Group-HC and Group-I boars was similar during the study, and the plasma testosterone profile (Kosco et al, 1987) resembles that of the relative mass of Leydig cytoplasm of Group-I boars given in Fig.…”

Section: Methodsmentioning

confidence: 99%

Development of the testicular interstitium after neonatal hemicastration in the boar

Kosco

Loseth²,

Crabo³

1989

Reproduction

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Serum Testosterone Concentrations in Embryonic and Fetal Pigs During Sexual Differentiation

Abstract: ABSTRACT

Cited by 71 publications

References 25 publications

Changes of testicular aromatase expression during fetal development in male pigs (sus scrofa)

Changes of testicular aromatase expression during fetal development in male pigs (sus scrofa)

Expression levels of Mullerian-inhibiting substance, GATA4 and 17alpha-hydroxylase/17,20-lyase cytochrome P450 during embryonic gonadal development in two diverse breeds of swine

Development of the testicular interstitium after neonatal hemicastration in the boar

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