Evidence for a peptidic factor in spermatozoa inhibiting the ovarian maturation

Lugaro, G; Carrea, Giacomo; Casellato, Maria Maddalena; Mazzola, G.; Fachini, G

doi:10.1016/0304-4165(73)90218-3

Cited by 16 publications

(8 citation statements)

References 8 publications

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“…Inhibin acts slowly over periods of hours or days to modulate pituitary responsiveness to Gn-RH in vitro and presumably has a similar action in vivo (Franchimont et al 1977;Setchell et al 1977). The chemistry of inhibin is not certain, but since it is inactivated by treatment with proteolytic enzymes it is probably a peptide and it may exist in more than one form (Lugaro, Carrea, Casellato, Mazzola & Fachini, 1973;Franchimont et al 1975;Hopkinson et al 1975;Chari, Duraiswami & Franchimont, 1978;Franchimont et al 1978). It is stable in lyo¬ philized crude protein preparations, resistant to acid pH and precipitates in the globulin fraction with ammonium sulphate.…”

Section: Usefulnessmentioning

confidence: 96%

A Bioassay for Inhibin Using Pituitary Cell Cultures

Eddie¹,

Baker²,

Higginson³

et al. 1979

Journal of Endocrinology

103

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A bioassay for inhibin based on the suppression of gonadotrophin releasing hormone (Gn-RH)-stimulated secretion of FSH by primary monolayer cultures of rat anterior pituitary cells is described. The cultures were exposed to standard or test materials for 3 days. The levels of FSH in the media were measured by radioimmunoassay after exposure for 6 h to a maximally stimulating concentration of Gn-RH (10 nmol/l). The standard was prepared from ovine testicular lymph. Several preparations of proteins from gonadal tissues or secretions suppressed the levels of FSH in parallel with the standard. The levels of LH were also reduced but higher doses of active material were required. Non-specificity from cell damage and inactivation of Gn-RH have been excluded. The secretion of gonadotrophins by the pituitary cells was also inhibited by androgens, but not in parallel with the standard and secretion of LH was affected more than that of FSH. Control lymph protein preparations from castrated sheep had no detectable activity. The assay was sensitive and had adequate precision and practicability. It has proved useful for monitoring preliminary steps in the purification of inhibin.

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Section: Usefulnessmentioning

confidence: 96%

A Bioassay for Inhibin Using Pituitary Cell Cultures

Eddie¹,

Baker²,

Higginson³

et al. 1979

Journal of Endocrinology

103

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“…The amount of steroid which will suppress the concentration of luteinizing hormone (LH) in the plasma of castrated rats to the concentration found in intact animals fails to suppress the level of FSH to a similar extent (Swerdloff, Walsh & Odell, 1972;Kalra, Fawcett, Krulich & McCann, 1973; Verjans, EikNes, Aafjes, Veis & van der Molen, 1974), and FSH is only suppressed in intact animals with supraphysiological doses of testosterone or oestradiol (de Jong, Uilenbroek & van der Verjans, van der Molen & Eik-Nes, 1975). These observations could be explained by postulating the existence of a second testicular hormone, ' inhibin ' (McCullagh, 1932), with a specific inhibitory effect on pituitary secretion and/or synthesis of FSH. Evidence for the existence of such a hormone has been given by Lugaro, Carrea, Casellato, Mazzola & Fachini (1973) ;Lugaro, Casellato, Mazzola, Fachini & Carrea (1974); Setchell & Jacks (1974) ;Franchimont, Chari & Demoulin (1975) ;Franchimont, Chari, Hagelstein & Duraiswami (1975) and Keogh, Lee, Rennie, Burger, Hudson & De Kretser (1976), who isolated extracts with specific FSH-suppressing activity from bull spermatozoa, sheep rete testis fluid, bull seminal plasma and homogenized bull testes. Recently, de Jong & Sharpe (1976a) observed that bovine follicular fluid contained a high-molecular-weight substance with inhibin-like activity.…”

Section: Introductionmentioning

confidence: 97%

Gonadotrophins, Testosterone and Spermatogenesis in Neonatally Irradiated Male Rats: Evidence for a Role of the Sertoli Cell in Follicle-Stimulating Hormone Feedback

Jong¹,

Sharpe²

1977

Journal of Endocrinology

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Peripheral concentrations of FSH in the male rat seem to be regulated in part by a protein hormone, inhibin, which originates from the testes. In an attempt to ascertain which type of testicular cell secretes inhibin, groups of male rats were irradiated prenatally or on days 4, 6 or 8 of postnatal life, and killed at 21, 51 or 81 days of age together with castrated and intact controls. The concentrations of FSH and LH in the pituitary gland, and FSH, LH and testosterone in the plasma were estimated for each animal, and the numbers of each class of intratubular cell in the testes were calculated. Rats irradiated neonatally had fewer Sertoli cells than controls at all ages studied, while the numbers of Sertoli cells in rats irradiated prenatally were higher than those in controls on day 21. The number of spermatogenic cells was usually decreased in rats irradiated postnatally. In the rats irradiated prenatally normal numbers of spermatogenic cells were found at day 51. Numbers of spermatogenic cells were significantly correlated with the number of Sertoli cells at the ages of 51 and 81 days. The concentrations of FSH in the plasma usually increased in the postnatally irradiated animals on days 21 and 51, but not on day 81; prenatal irradiation did not result in altered levels of FSH at any age. Peripheral levels of LH and testosterone were not affected by irradiation. The concentration of FSH in the plasma was negatively correlated with the number of Sertoli cells in all age groups, whereas significant correlations between the level of FSH and the number of spermatogenic cells were only found at days 51 and 81. It is concluded from these data that the Sertoli cell is the most likely source of inhibin.

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“…which is utilized for all the experiments reported here contains peptides as almost the sole component. Tryptic, papain, pepsin, as well as HC1 hydrolysis destroyed the inhibitory action on ovarian maturation [Lugaro et at., 1973].…”

Section: Methodsmentioning

confidence: 99%

“…Subsequent purification studies and a more extensive characterization of the in hibiting factor were reported. We isolated a fraction in which the ac tivity, still significant in vivo at a l-/rg dose, was bound to a compound o f peptidic nature [Lugaro et al, 1973]. Because no castration cells developed in the pituitary of ovariectomized rats treated with the spermatozoan factor, we postulated that the lack of ovarian maturation was due to a central inhibitory action on the reproductive system.…”

mentioning

confidence: 99%

Evidence for the Existence in Spermatozoa of a Factor Inhibiting the Follicle Stimulating Hormone Releasing Hormone Synthesis

Lugaro¹,

Casellato²,

Mazzola³

et al. 1974

Neuroendocrinology

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A peptidic factor, isolated from bull spermatozoa and previously described as inhibiting ovarian maturation, reduces the release of follicle stimulating hormone (FSH) in the male rat, when administered intraventricularly. This action is still evident at a dose level of 100 ng. It seems reasonable to postulate that the factor acts at the level of central nervous structures, because the follicle stimulating hormone releasing hormone (FSH-RH) hypothalamic content is also greatly decreased. However, luteinizing hormone (LH) release and luteinizing hormone releasing hormone (LH-RH) are not affected by this factor.

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Evidence for a peptidic factor in spermatozoa inhibiting the ovarian maturation

Cited by 16 publications

References 8 publications

A Bioassay for Inhibin Using Pituitary Cell Cultures

A Bioassay for Inhibin Using Pituitary Cell Cultures

Gonadotrophins, Testosterone and Spermatogenesis in Neonatally Irradiated Male Rats: Evidence for a Role of the Sertoli Cell in Follicle-Stimulating Hormone Feedback

Evidence for the Existence in Spermatozoa of a Factor Inhibiting the Follicle Stimulating Hormone Releasing Hormone Synthesis

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