Bovine Reproduction. Группа авторов

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Bovine Reproduction - Группа авторов


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century, Leydig cells have been considered the probable source of testicular androgens [65]. Berthold [66] was the first to observe from experimentation with the rooster that the testes produced a substance that influenced secondary sex organ development and maintenance [26]. The first isolation of an androgen, androsterone, from human urine [67] and the crystallization of testosterone from bull testes [11] established the major site of testosterone production as the testis. Extensive literature has emerged over the past 50 years on the function of the Leydig cell. These studies, employing a variety of techniques, have identified and confirmed the Leydig cells as the primary source of testicular androgens and elucidated the important pathways in androgen biosynthesis [5, 26, 52, 68]. LH has also been confirmed as the major pituitary hormonal stimulus on the Leydig cells [46]. Ewing et al. [68] have suggested that because Leydig cells are concentrated in clusters in the interstitial tissue of the testis, they must influence seminiferous tubular and peripheral androgen‐dependent functions (accessory sex glands) by hormonal signals rather than by cell‐to‐cell interaction.

Hormone family Hormone Site of synthesis
Steroid family
Cholesterol (27 carbons) Cholesterol22‐hydroxycholesterol20,22,‐dihydroxycholesterol De novo biosynthesis, fat deposits, or from blood
Progestins (21 carbons) ∆5‐Pregnenolone17α‐Hydroxypregnenolone17α‐HydroxyprogesteroneProgesterone Leydig cells (mitochondria)
Androgens (19 carbons) Dehydroepiandrosterone∆4‐Androstenedione∆5‐AndrostenediolTestosteroneDihydrostestosterone Leydig cells (microsomal compartments)
Estrogens (18 carbons) EstroneEstradiol‐17β Leydig cells
Peptide family
Relaxin‐like peptides Relaxin/insulin‐like peptide‐3 Leydig cells
Neuropeptides OxytocinGlial cell‐derived factor Leydig cellsSeroli cells
Cytokine family
ActivinInhibin Sertoli cellsSertoli cells
Glycoproteins
Androgen binding proteinTesticular transferrin Sertoli cellsSertoli cells

      The unusual abundance of Leydig cells in


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