Development of the testicular interstitium after neonatal hemicastration in the boar

Kosco, M. S.; Loseth, K. J.; Crabo, B. G.

doi:10.1530/jrf.0.0870013

Cited by 7 publications

(6 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…After unilateral castration at any age, plasma estrone and testosterone concentrations remained constant, indicative of an immediate increase in testicular steroidogenesis within the remaining testicle. These compensatory increases within the interstial compartment in response to unilateral castration have been described in detail [40].…”

Section: Discussionmentioning

confidence: 88%

Interrelationships of Porcine X and Y Chromosomes with Pituitary Gonadotropins and Testicular Size1

Ford

Wise

Lunstra

et al. 2001

Biology of Reproduction

View full text Add to dashboard Cite

Endocrine and testicular responses to unilateral castration on 1, 10, 56, or 112 days of age were characterized in 132 Chinese Meishan (MS) x White composite (WC) crossbred boars in which testicular size associates with a quantitative trait locus (QTL) on X chromosome. At 220 days of age, testicles of boars unilaterally castrated on Day 1 or 10 weighed more and had greater total daily sperm production (DSP) than one testicle of bilaterally intact boars (P < 0.05); compensation did not double these two responses. Boars with MS alleles at the X chromosome QTL had smaller testicles, darker colored parenchyma, and lower total DSP than boars with WC alleles (P < 0.05). The MS alleles engendered greater (P < 0.05) plasma FSH and LH during puberty than WC alleles. Plasma FSH increased (P < 0.05) within 48 h of unilateral castration on Days 1, 10, and 56. Subsequent increases occurred earlier during puberty (P < 0.05) after unilateral castration at younger ages than after unilateral castration at older ages. Pubertal increases in plasma FSH and LH were greater (P < 0.05) in boars with MS alleles than in those with WC alleles for the X chromosome QTL. Breed of Y chromosome had no effect on testicular traits, FSH, testosterone, or estrone. For LH, boars with an MS Y chromosome had greater (P < 0.01) plasma LH across all ages than boars with a WC Y chromosome. We conclude that a gene or groups of genes that reside on the porcine X chromosome regulate testicular development and pubertal gonadotropin concentrations.

show abstract

Section: Discussionmentioning

confidence: 88%

Interrelationships of Porcine X and Y Chromosomes with Pituitary Gonadotropins and Testicular Size1

Ford

Wise

Lunstra

et al. 2001

Biology of Reproduction

View full text Add to dashboard Cite

show abstract

“…This initial lag in testicular development in reduced‐estrogen boars is consistent with studies in the bank vole that suggest that administration of estradiol accelerates testicular maturation and onset of spermatogenesis (Gancarczyk et al, 2004). Final testis size can be increased by hemicastration (Putra and Blackshaw, 1985), but the procedure occurs at the expense of total sperm production (Kosco et al, 1989a,b). We have shown previously that inhibition of aromatase by letrozole suppresses estradiol levels by over 90% without inducing any change in gonadotropin levels (At‐Taras et al, 2006).…”

Section: Discussionmentioning

confidence: 99%

Reducing Estrogen Synthesis in Developing Boars Increases Testis Size and Total Sperm Production

At-Taras

Berger

McCarthy

et al. 2006

Journal of Andrology

View full text Add to dashboard Cite

The abundant production of testicular estrogens and the presence of both ESR1 and ESR2 within boar testes are consistent with a role for estrogen in testicular development and/or function in this species. This study was aimed at determining the role of endogenous estrogen in the regulation of testicular development and function, including the effects on testis weight, histology, sperm production (detergent-resistant spermatid numbers), Sertoli cell numbers, and Leydig cell volume in the boar. Twenty-eight littermate pairs of boars were assigned to groups as follows: 1 boar from each pair was assigned to the control group (vehicle) and the other was assigned to treatment and received 0.1 mg/kg body weight of an aromatase enzyme inhibitor (letrozole) orally each week beginning at 1 week of age until castration at 2, 3, 4, 5, 6, 7, or 8 months of age. Testes were weighed and testicular parenchyma was recovered for determination of histology and detergent-resistant spermatid numbers, and for determination of Sertoli cell number and Leydig cell volume by staining for GATA-4 and 17-a hydroxylase/17-20 lyase respectively. Testes of aromatase-inhibited boars initially exhibited delayed lumen formation, lower testicular weight, fewer detergentresistant spermatids, and fewer Sertoli cells, but by 7 to 8 months, these boars had recovered and had larger testes, more detergentresistant spermatids per testis, and more Sertoli cells. Total Leydig cell volume increased in proportion to testis size. Reducing endogenous estrogen is consistent with a delay in testicular maturation/puberty that allows for a longer window for the proliferation of Sertoli cells and maturation of Leydig cells, resulting in larger testes and higher spermatid production.

show abstract

“…Steroid concentrations reach a peak in the first month of life, decline transiently, then increase again as puberty is initiated, because of a decrease in clearance, as well as an increase in steroid production (8). The interstitial compartment comprises the majority of testicular volume in the early neonatal pig (9,10), is the site of expression of steroidogenic enzymes in the boar (11,12), and therefore the major cellular site of both androgen and estrogen synthesis. Leydig cell development and function (13) is dependent on pituitary support in late gestation (14) and postnatally (15)(16)(17)(18)(19)(20)(21).…”

mentioning

confidence: 99%

“…Leydig cell development and function (13) is dependent on pituitary support in late gestation (14) and postnatally (15)(16)(17)(18)(19)(20)(21). The compensatory increase in testicular interstitial and tubular spaces, and total mass, which is seen following unilateral castration in the neonatal period (10,22,23), is associated with a sustained increase in plasma FSH, but not testosterone or LH concentrations (24). In contrast to the extensive studies conducted on laboratory rodents (13,25,26), relatively little is known of the acute effects of gonadotropic stimulation in vivo on the components of the testicular steroidogenic apparatus of pigs beyond peripheral steroid concentrations.…”

mentioning

confidence: 99%

Regulation of Microsomal P450, Redox Partner Proteins, and Steroidogenesis in the Developing Testes of the Neonatal Pig

et al. 2002

View full text Add to dashboard Cite

Testicular growth and plasma androgen concentrations increase markedly in the first weeks of neonatal life of pigs. The regulation of steroidogenesis through this period was examined by measuring total microsomal cytochromes P450 (P450), 17alpha-hydroxylase/17,20-lyase P450 (P450c17) and aromatase P450 (P450arom) enzyme activities, and the redox partner proteins nicotinamide adenine dinucleotide phosphate, reduced form (NADPH)-cytochrome P450 reductase (reductase) and cytochrome b(5) in testicular microsomes. Testes were collected from 1-24 d of age, and testicular development was suppressed by a GnRH antagonist in some animals from d 1-14. Both 17/20-lyase and aromatase activities increased from d 1-7 but not thereafter, and 17-20-lyase activity was always at least 200-fold higher than aromatase activity. Reductase decreased in wk 1, then increased to d 24. No changes were seen in cytochrome b(5) expression. GnRH antagonist treatment suppressed plasma LH, testosterone and testes growth to d 14. 17,20-Lyase and aromatase activities in testicular microsomes were reduced by 20% and 50%, respectively. Total microsomal P450 concentration was reduced by 50% on d 7, but there was no effect of treatment on reductase or cytochrome b(5) expression. These data support the hypothesis that the rise in neonatal testicular androgen secretion is more likely due to gonadotropin-stimulated gonadal growth, rather than specific P450c17 expression. Neither P450c17 nor P450arom can account for the decline in total microsomal P450. Reductase and cytochrome b(5) expression appears to be constitutive, but reductase levels saturate both P450c17 and P450arom.

show abstract

Development of the testicular interstitium after neonatal hemicastration in the boar

Abstract: Summary. Development of the prepubertal interstitium of the right testes was characterized every 14 days from 10 to 122 days of age in intact boars (I)

Cited by 7 publications

References 27 publications

Interrelationships of Porcine X and Y Chromosomes with Pituitary Gonadotropins and Testicular Size1

Interrelationships of Porcine X and Y Chromosomes with Pituitary Gonadotropins and Testicular Size1

Reducing Estrogen Synthesis in Developing Boars Increases Testis Size and Total Sperm Production

Regulation of Microsomal P450, Redox Partner Proteins, and Steroidogenesis in the Developing Testes of the Neonatal Pig

Contact Info

Product

Resources

About