scholarly journals Stimulation of Sertoli cell proliferation: defining the response interval to an inhibitor of estrogen synthesis in the boar

Reproduction ◽  
2012 ◽  
Vol 143 (4) ◽  
pp. 523-529 ◽  
Author(s):  
Trish Berger ◽  
Lisa Kentfield ◽  
J F Roser ◽  
Alan Conley
Keyword(s):  
Cell Proliferation ◽  
Sertoli Cell ◽  
Cell Number ◽  
Cell Numbers ◽  
Response Interval ◽  
Estrogen Synthesis ◽  
Letrozole Treatment ◽  
Size At Sexual Maturity ◽  
Testicular Size ◽  
Second Wave

Sertoli cell proliferation occurs in two major waves after birth, one neonatally and another prepubertally, each contributing to final testicular size and sperm production. However, little is known about the regulation of either wave. We have previously shown that letrozole, an inhibitor of estrogen synthesis, increases Sertoli cell number and testicular size at sexual maturity in boars. These studies were conducted to determine whether letrozole affects the first or second proliferative wave. Boars were treated with letrozole during the first wave (treatment at 1, 3, and 5 weeks), less frequently (1 week of age only, or 1 and 5 weeks), on postnatal day 1, or during the second wave (weeks 11–16). Sertoli cells were enumerated in testes and estrogen concentrations were evaluated in serum and testes. Compared with vehicle controls, letrozole reduced estrogen in boars treated at weeks 1 and 5 or 1, 3, and 5, on postnatal day 1, or prepubertally. However, Sertoli cell numbers were increased only in boars treated at 1, 3, and 5 weeks of age. Neither perinatal (1 day old) nor prepubertal letrozole treatment affected Sertoli cell numbers. Hence, Sertoli cell proliferation was sensitive to letrozole only if letrozole was administered throughout the first wave, even though estrogen synthesis was effectively inhibited at all ages. These data indicate that the neonatal but not the prepubertal window of Sertoli cell proliferation is sensitive to an inhibitor of estrogen synthesis; this suggests that these two waves are differently regulated.

scholarly journals Effect of Hypophysectomy, Sex of Host, and/or Number of Transplanted Testes on Sertoli Cell Number and Testicular Size of Syngeneic Testicular Grafts in Fischer Rats1

1996 ◽  
Vol 54 (5) ◽  
pp. 960-969 ◽  
Author(s):  
Larry Johnson ◽  
Lisa C. Suggs ◽  
Yvonne M. Norton ◽  
Thomas H. Welsh ◽  
Clynn E. Wilker
Keyword(s):  
Sertoli Cell ◽  
Cell Number ◽  
Testicular Size

scholarly journals Stereological evaluation of Sertoli cell ontogeny during fetal and neonatal life in two diverse breeds of swine

2003 ◽  
Vol 178 (3) ◽  
pp. 395-403 ◽  
Author(s):  
SA McCoard ◽  
TH Wise ◽  
DD Lunstra ◽  
JJ Ford
Keyword(s):  
Sertoli Cell ◽  
Sertoli Cells ◽  
Prenatal Development ◽  
Late Gestation ◽  
Postnatal Life ◽  
Interstitial Tissue ◽  
Cell Numbers ◽  
Barrier Formation ◽  
Cell Population Growth ◽  
Testicular Size

Chinese Meishan (MS) boars have smaller testes due to fewer Sertoli cells compared with White Composite (WC) boars. The objective was to describe Sertoli cell development relative to circulating FSH concentrations in fetal and neonatal MS and WC boars. Testes and blood samples were collected on days 60, 75, 90 and 105 postcoitum (dpc) and 1, 7, 14 and 25 postpartum (dpp). One testis was immunostained for GATA4 or Ki67 antigen to evaluate total and proliferating Sertoli cell numbers respectively. Testicular size was greater (P<0.01) in WC than MS boars at all ages, associated with a greater mass of interstitial tIssue. Tubular mass (P<0.01) was greater in prenatal WC boars, but postnatally increased more rapidly (P<0.001) in MS boars, exceeding WC boars by 25 dpp. Sertoli cell numbers increased with age, was greater (P<0.001) in WC than MS boars during prenatal development but increased rapidly (P<0.01) by 1 dpp in MS and thereafter was similar in both breeds. The proportion of Ki67-positive Sertoli cells was maximal at 90 dpc, declining thereafter, did not differ between breeds through 7 dpp, but was greater (P<0.05) in WC than MS boars at 14 and 25 dpp. Plasma FSH concentrations were greater (P<0.05) in WC than MS boars at 75 dpc. FSH concentrations were elevated at 105 dpc (MS) and 1 dpp (WC) but declined thereafter with advancing postnatal age in both breeds. This study illustrates that late gestation represents the period of maximal Sertoli cell proliferation. Despite asynchronous Sertoli cell population growth between breeds during early postnatal life, differential mature Sertoli cell numbers and testicular size are probably due to differences in duration of the proliferative period after 25 dpp, potentially regulated by Sertoli cell maturation and blood-testis barrier formation. These events were not associated with fetal or early postnatal changes in FSH secretion.

Exogenous platelet-activating factor stimulates cell proliferation in mouse pre-implantation embryos prior to the fourth cell cycle and shows isoform-specific stimulatory effects

Zygote ◽  
2001 ◽  
Vol 9 (3) ◽  
pp. 261-268 ◽  
Author(s):  
Neil R. Stoddart ◽  
William E. Roudebush ◽  
Steven D. Fleming
Keyword(s):  
Cell Proliferation ◽  
Biological Activities ◽  
Platelet Activating Factor ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Embryonic Cell ◽  
Cell Stage ◽  
Cell Numbers ◽  
Paf Receptor

Mouse embryos secrete molecules homologous to platelet-activating factor (PAF), termed embryo-derived PAF (EPAF), which act in an autocrine/paracrine fashion to stimulate embryonic development in vitro. Mouse EPAF is thought to consist predominantly of hexadecyl (C16) and octadecyl (C18) PAF-like components. Mouse pre-implantation embryos cultured with exogenous PAF from the early cleavage stages exhibit increased blastocyst cell numbers and rates of mitosis around the 8-cell stage. We investigated whether exogenous PAF could specifically stimulate embryonic cell proliferation prior to the blastocyst stage in the mouse and also compared the biological activities of the C16 and C18 PAF isoforms as follows. Embryos were cultured for either 24 h or 120 h from the 2-cell stage and their total cell numbers were determined or their development assessed in terms of their incidence of successful zona-hatching respectively. In each case, embryos were cultured in unsupplemented medium or in medium supplemented with either C16 or C18 PAF (0.5 μM). Compared with controls, culture with C16 PAF produced a significant stimulation of mean total per number per embryo and a significant increase in the incidence of successful zona-hatching, whilst culture with C18 PAF had no significant effect. We then cultured 1-cell zygotes for 48 h in unsupplemented medium or medium supplemented with either an equimolar mixture of C16 and C18 PF or with either C16 or C18 PF alone (each at 0.2 μM). Embryos were also scored for cell number at 4 h and 30 h of culture. Although no significant effect on mean cell number per embryo was seen following 4 h or 30 h of culture with a mixed C16/C18 PAF preparation, culture for 48 h with a mixed C16/C18 PAF preparation or with C16 PAF alone produced a significant increase in mean cell number per embryo compared with controls - an effect that is likely to be receptor-mediated, since culture with an equivalent concentration of C18 PAF had no significant effect compared with controls. We have demonstrated that mouse zygotes/embryos can respond in a specific manner to exogenous hexadecyl PAF in terms of increased rates of cell proliferation prior to cavitation, and must be capable of doing so at some time between the first and third, and also between the second and fourth, cell cycles. Such embryos presumably express one or more classes of functional PAF-receptor molecule during this period (i.e. as early as during the 1-, 2- or 4-cell stages). We have also demonstrated that embryonic response to exogenous PAF is significantly isoform-specific, which may reflect differences between the two isoforms either in affinity for binding to putative embyronic PAF-receptor molecules or in their ability to elicit a stimulatory response following binding. This observation calls into question the use of preparations containing a mixture of hexadecyl and octadecyl PAF isoforms, particularly in dose-response studies, in the mouse.

Neonatal administration of FSH increases Sertoli cell numbers and spermatogenesis in gonadotropin-deficient (hpg) mice

1996 ◽  
Vol 151 (1) ◽  
pp. 37-48 ◽  
Author(s):  
J Singh ◽  
D J Handelsman
Keyword(s):  
Cell Proliferation ◽  
Germ Cell ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Postnatal Life ◽  
Testis Size ◽  
Cell Numbers ◽  
Natural Time ◽  
Neonatal Administration

Abstract We previously demonstrated that androgens alone, in the complete absence of gonadotropins, initiated qualitatively complete spermatogenesis in hypogonadal (hpg) mice. Although germ cell to Sertoli cell ratios were normal in hpg mice with androgen-induced spermatogenesis, testicular size, Sertoli cell and germ cell numbers only reached 40% of those of non-hpg mice, and Sertoli cell numbers were unaffected by androgen treatment started at 21 days of age. We postulated that these observations were due to diminished gonadotropin-dependent Sertoli cell proliferation during perinatal life while the Sertoli cells still exhibited normal carrying capacity for mature germ cells. In order to test this hypothesis, we examined the effects of administering androgens and gonadotropins to hpg mice during the first 2 weeks of postnatal life when Sertoli cells normally continue to proliferate. The study end-points were Sertoli and germ cell numbers in hpg mice following induction of spermatogenesis by 8 weeks treatment with 1 cm subdermal silastic testosterone implants. Newborn pups (postnatal day 0–1) were injected s.c. with recombinant human FSH (rhFSH) (0·5 IU/20 μl) or saline once daily for 14 days, with or without a single dose of testosterone propionate (TP) (100 μg/20 μl arachis oil) or human chorionic gonadotropin (hCG) (1 IU/20 μl). Untreated hpg and phenotypically normal littermates were studied as concurrent controls. At 21 days of age, all treated weanling mice received a 1 cm silastic subdermal testosterone implant and, finally, 8 weeks after testosterone implantation, all mice were killed. As expected, qualitatively complete spermatogenesis was induced in all groups by testosterone despite undetectable circulating FSH levels. Exogenous rhFSH increased testis size by 43% (P<0·002) but a single neonatal dose of either TP or hCG reduced the FSH effect although neither TP nor hCG had any effect alone. In contrast, a single neonatal dose of TP or hCG increased final seminal vesicle size whereas FSH had no effect. FSH and TP treatment significantly increased absolute numbers of testicular spermatids compared with saline treatment, whereas hCG and TP significantly increased testicular sperm when expressed relative to testis size. Stereological evaluation of Sertoli and germ cell numbers demonstrated a rise in the absolute numbers of Sertoli and all germ cell populations induced by neonatal administration of hormones. When expressed per Sertoli cells the numbers of germ cells in the treated mice were between 85 and 90% of non-hpg controls. We conclude that exogenous FSH treatment during the first 2 weeks of postnatal life, coinciding with the natural time of Sertoli cell proliferation, increases Sertoli cell numbers and thereby the ultimate size of the mature testis and its germ cell production. Thus neonatal gonadotropin secretion may be a critical determinant of the sperm-producing capacity of the mature testis. In addition, neonatal exposure to androgens could be important for the imprinting of sex accessory organs in hpg mice, with the long-term effects of altering the sensitivity of the accessory organs to exogenous testosterone later in life. Journal of Endocrinology (1996) 151, 37–48

scholarly journals Effect of Developmental Age or Time after Transplantation on Sertoli Cell Number and Testicular Size in Inbred Fischer Rats1

1996 ◽  
Vol 54 (5) ◽  
pp. 948-959 ◽  
Author(s):  
Larry Johnson ◽  
Lisa C. Suggs ◽  
Yvonne M. Norton ◽  
Wayne C. Zeh
Keyword(s):  
Sertoli Cell ◽  
Cell Number ◽  
Developmental Age ◽  
Testicular Size

Acute reduction of Sertoli cell numbers during development leads to a subsequent reduction in sperm numbers in adulthood

2014 ◽  
Author(s):  
Annalucia L Darbey ◽  
Peter O'Shaughnessy ◽  
Jean-Luc Pitetti ◽  
Serge Nef ◽  
Lee Smith ◽  
...  
Keyword(s):  
Sertoli Cell ◽  
Subsequent Reduction ◽  
Cell Numbers

Aromatase and 11β-hydroxysteroid dehydrogenase 2 localisation in the testes of pigs from birth to puberty linked to changes of hormone pattern and testicular morphology

2008 ◽  
Vol 20 (4) ◽  
pp. 505 ◽  
Author(s):  
A. Wagner ◽  
R. Claus
Keyword(s):  
Blood Plasma ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Leydig Cells ◽  
Hydroxysteroid Dehydrogenase ◽  
Blood Collection ◽  
Testicular Development ◽  
Post Mortem ◽  
Cell Numbers ◽  
Testicular Morphology

Oestrogens and glucocorticoids are important for spermatogenesis and are regulated via aromatase for oestradiol synthesis and 11β-hydroxysteroid dehydrogenase 2 (11β-HSD 2) as an inactivator of cortisol. In the present study postnatal changes of these two enzymes were monitored together with testicular development and hormone concentrations. Pigs were assigned to three periods: Weeks 0–5, Weeks 5–11 or Weeks 11–17. In Period 1, groups of four piglets were killed after each week. Blood plasma and testes were sampled immediately post mortem. For Periods 2 and 3, groups of six pigs were fitted with vein catheters for daily blood collection. Testes from all pigs were obtained after killing. Levels of testosterone, oestradiol, LH, FSH and cortisol were determined radioimmunologically. The 11β-HSD 2- and aromatase-expressing cells were stained immunocytochemically. All hormones were maximal 2 weeks after birth. A rise of LH, testosterone and oestradiol occurred again at Week 17. FSH and cortisol remained basal. Parallel to the first postnatal rise, the presence of aromatase and 11β-HSD 2 in Leydig cells increased, together with germ and Sertoli cell numbers. Expression was low from 3 to 5 weeks, was resumed after Week 5 and was maximal at Week 17. The amount of 11β-HSD 2 in germ cells was greatest at birth, decreased thereafter and was absent after Week 3.

Summer temperature in northeastern Siberia since 1642 reconstructed from tracheid dimensions and cell numbers of Larix cajanderi

2003 ◽  
Vol 33 (10) ◽  
pp. 1905-1914 ◽  
Author(s):  
Irina P Panyushkina ◽  
Malcolm K Hughes ◽  
Eugene A Vaganov ◽  
Martin AR Munro
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Cell Number ◽  
Cell Wall Thickness ◽  
Cell Dimension ◽  
Cell Numbers ◽  
Age Related ◽  
Cambial Age ◽  
Northeastern Siberia ◽  
Larix Cajanderi

We reconstructed air temperature for two periods in the growth season from cell dimension and cell number variability in cross-dated tree rings of Larix cajanderi Mayr. from northeastern Siberia. Thirteen tree-ring chronologies based on cell size, cell wall thickness, and cell number were developed for AD 1642–1993. No clear evidence was found of an age-related trend in cell dimensions in the sampled materials, but cell numbers were correlated with cambial age. The chronologies contain strong temperature signals associated with the timing of xylem growth. We obtained reliable reconstructions of mean June temperature from the total cell number and July–September temperature from the cell wall thickness of latewood. June temperature and July–September temperature covaried for most of the period from AD 1642 to AD 1978. After that time, June temperature became cooler relative to July–September temperature. This difference caused disproportional changes in earlywood tracheids because of the late start of growth and cool conditions in June followed by warming during the rest of the season. The identification of this unusual recent change has shown that intraseasonal resolution may be achieved by cell dimension and cell number chronologies.

scholarly journals Müllerian Inhibiting Substance Is Required for Germ Cell Proliferation during Early Gonadal Differentiation in Medaka (Oryzias latipes)

Endocrinology ◽  
2007 ◽  
Vol 149 (4) ◽  
pp. 1813-1819 ◽  
Author(s):  
Eri Shiraishi ◽  
Norifumi Yoshinaga ◽  
Takeshi Miura ◽  
Hayato Yokoi ◽  
Yuko Wakamatsu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Germ Cell ◽  
Germ Cells ◽  
Sex Differentiation ◽  
Somatic Cells ◽  
Oryzias Latipes ◽  
Cell Number ◽  
Gonadal Differentiation ◽  
Loss Of Function ◽  
Germ Cell Proliferation

Müllerian inhibiting substance (MIS) is a glycoprotein belonging to the TGF-β superfamily. In mammals, MIS is responsible for the regression of Müllerian ducts in the male fetus. However, the role of MIS in gonadal sex differentiation of teleost fish, which have no Müllerian ducts, has yet to be clarified. In the present study, we examined the expression pattern of mis and mis type 2 receptor (misr2) mRNAs and the function of MIS signaling in early gonadal differentiation in medaka (teleost, Oryzias latipes). In situ hybridization showed that both mis and misr2 mRNAs were expressed in the somatic cells surrounding the germ cells of both sexes during early sex differentiation. Loss-of-function of either MIS or MIS type II receptor (MISRII) in medaka resulted in suppression of germ cell proliferation during sex differentiation. These results were supported by cell proliferation assay using 5-bromo-2′-deoxyuridine labeling analysis. Treatment of tissue fragments containing germ cells with recombinant eel MIS significantly induced germ cell proliferation in both sexes compared with the untreated control. On the other hand, culture of tissue fragments from the MIS- or MISRII-defective embryos inhibited proliferation of germ cells in both sexes. Moreover, treatment with recombinant eel MIS in the MIS-defective embryos dose-dependently increased germ cell number in both sexes, whereas in the MISRII-defective embryos, it did not permit proliferation of germ cells. These results suggest that in medaka, MIS indirectly stimulates germ cell proliferation through MISRII, expressed in the somatic cells immediately after they reach the gonadal primordium.

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