Sertoli cell ultrastructure. II. Morphological effects of hypophysectomy in pubescent pigs

Chevalier, Michelle

doi:10.1051/rnd:19790504

Cited by 7 publications

(4 citation statements)

References 16 publications

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“…Immature Sertoli cells of several species show increased mitotic activity in response to FSH (Courot, 1967;Steinberger & Steinberger, 1977;Fritz, 1978;Chevalier, 1979;Means et ai, 1980) and may be involved in compensatory Sertoli cell proliferation in neonatally hemicastrated rams and rats (Waites et ai, 1983;Orth et al, 1984). FSH in Group-HC boars was elevated above values for intact animals only during the last 14 days of compensatory Sertoli cell proliferation, whereas plasma GH concentration in Group-HC boars was elevated during the entire period of compensatory proliferation of Sertoli cells (Kosco et ai, 1987 Staining 1 % toluidine blue; 400.…”

Section: Discussionmentioning

confidence: 99%

Development of the seminiferous tubules after neonatal hemicastration in the boar

Kosco¹,

Loseth²,

Crabo³

1989

Reproduction

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Section: Discussionmentioning

confidence: 99%

Development of the seminiferous tubules after neonatal hemicastration in the boar

Kosco¹,

Loseth²,

Crabo³

1989

Reproduction

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“…Dark supporting cells were characterized by densely packed granular endoplasmic reticulum. Dark Sertoli cells in turn were previously observed in the mature boar testis [ 32 ]. The author of the latter study suggested that the difference in electron density of the supporting cells was related to their varying reactivity to the absence of gonadotropin hormones.…”

Section: Discussionmentioning

confidence: 89%

“…As reported by Rawlings et al [ 21 ], the differentiation of mature Sertoli cells appears to be complete between 30 and 40 weeks of age. The initial data from the 1960s to the 1980s indicated that there may be two types of Sertoli cells in the testes, namely dark and light cells [ 4 , 31 , 32 , 33 ]. Among the cells lining the seminiferous tubules in the calves examined, elongated dark supporting cells extending from the base towards the lumen were also observed.…”

Section: Discussionmentioning

confidence: 99%

Ultrastructure of the Bovine Testis in Cattle (Bos taurus): New View

Michałek,

Grabowska,

Oberska

et al. 2024

Animals

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The purpose of this study was to analyze the ultrastructure of the testes of sexually immature calves and reproductive bulls of the Polish Holstein-Friesian Black-and-White breed. Utilizing TEM, this study identified three distinct stages of seminiferous tubule development in calves, characterized by varying shapes, distributions, and arrangements of individual cells. In immature animals, early developing spermatocytes, prespermatogonia, and pre-Sertoli cells were observed within the seminiferous tubules. In sexually mature bulls, all cells of the spermatogenic series were observed, situated on a thin, multilayered basal lamina, which forms characteristic undulations. An abundant smooth endoplasmic reticulum was observed in the cytoplasm of spermatogonia in both groups of animals, forming characteristic membranous swirls. In adult bulls, spermatogonia maintain contact with each other through numerous cytoplasmic bridges and cell connections, forming small spaces with visible microvilli between them. The ultrastructural analysis facilitated the identification of morphological changes occurring during the maturation of pre-Sertoli cells, transitioning from a large euchromatic nucleus to a nucleus in which the formation of characteristic vesicles and tubules could be observed. It should also be emphasized that two types of Sertoli cells, namely dark and light electron-dense cells, can be found in cattle. These cells differ from each other, indicating that they may perform different functions. The widespread recognition of the presence of two types of Sertoli cells in cattle will undoubtedly contribute to a better understanding of the processes occurring within the testes and provide a basis for further research in this area.

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“…FSH specifically binds to Sertoli cells and, in conjunction with testosterone, controls the function and structure of this cell (Chevalier, 1979;Colenbrander el at, 1982). After binding to specific receptors, gonadotrophins elicit their biological response via various intracellular second messengers.…”

Section: Model Of Gonadotrophin Action Based On Invitro Studiesmentioning

confidence: 99%

Regulation and action of gonadotrophinsin pigs

Esbenshade¹,

Ziecikt²,

Britt³

2020

Proc

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Gonadotrophins, synthesized and secreted from the basophils of the adenohypophysis, bind to various target cells and elicit a wide variety of responses. Specific receptors for gonadotrophins have been found on plasma membranes of thecal, granulosa, luteal, endometrial and myometrial cells in the female and on Leydig and Sertoli cells in the Male. Gonadotrophins exert their effects through various intracellular second messengers and control biosynthetic pathways of steroid production in responsive cells. Gonadotrophins stimulate growth and development of antral follicles in the female. PMSG, FSH, or hourly pulses of GnRH, LH or a combination of LH and FSH induce follicular growth and development in prepubertal gilts and lactating and(or)anoestrous sows. The number of follicles Ilia t develop to ovula tory size in response to PMSG and FSH is dose-dependent, but pulsatile treatment with GnRH or gonadotrophins results in an ovulation rate similar to that observed during spontaneous follicular development. Endocrine changes resulting from treatments that induce follicular growth and development are similar to those observed during the follicular phase of the oestrous cycle. Hypophysectomy, hypophysial-stalk transection, active and passive immunization against GnRH, and active immunization against LH impair reproduction by interfering with normal follicular development in the female. Gonadotrophins, administered to gilts as repeated injections of whole pituitary extract or as pulses of GnRH agonist, do not stimulate follicular growth in gilts actively immunized against GnRH. Similarly, PMSG is ineffective in inducing follicular growth and development in gilts actively immunized against GnRH and after hypophysectomy or hypophysial-stalk transection. In contrast, PMSG is effective for inducing follicular development in hypophysial stalktransected pigs when pulses of GnRH are given simultaneously with the PM SG. These results suggest that agents in addition to the gonadotrophins are required for the full complement of follicular growth, recruitment and development. Insulin, growth factors and steroids modify the response of cells to the gonadotrophins and may mediate these effects. Other possibilities include substances released from the pituitary gland or GnRHlike peptide(s) produced by the ovary that act as autocrine or paracrine regulators of follicular development. Gonadotrophins stimulate testicular function in the male. Active immunization of mature boars against GnRH or LH results in testicular atrophy, depressed steroidogenic and spermatogenic functions and impaired libido. Treatment of boars immunized against GnRH with hCG restores steroidogenic function of the testes as evidenced by testosterone production. Gonadotrophins also exert an influence in thecentral nervous system. Administration of hCG intramuscularly or intracranially blocks the oestrogen-induced preovulatory LH surge in ovariectomized pigs via a short loop feedback control mechanism. Exogenous

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Sertoli cell ultrastructure. II. Morphological effects of hypophysectomy in pubescent pigs

Cited by 7 publications

References 16 publications

Development of the seminiferous tubules after neonatal hemicastration in the boar

Development of the seminiferous tubules after neonatal hemicastration in the boar

Ultrastructure of the Bovine Testis in Cattle (Bos taurus): New View

Regulation and action of gonadotrophinsin pigs

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