The Pituitary and Testis

1 Patterns of Secretion and Metabolism of the Gonadotrophic Hormones.- 1.1 Assay Methods.- 1.1.1 Human FSH, LH and Prolactin.- 1.1.2 Animal Gonadotrophins.- 1.2 Patterns of LH and FSH Secretion in Normal Men.- 1.3 Metabolic Clearance and Gonadotrophin Secretion Rates in Normal Men.- 1.3.1 MCR and Production Rate of LH.- 1.3.2 MCR and Production Rate of FSH.- 1.3.3 Initial Clearance of Gonadotrophin Subunits.- 1.3.4 Effect of Renal Disease on MCR.- 1.4 Summary.- 2 Control of FSH and LH Secretion.- 2.1 Sites of Production of FSH and LH.- 2.2 Hypothalamic Influences on FSH and LH Secretion.- 2.3 Influence of Testicular Feedback.- 2.3.1 Feedback Control of LH.- 2.3.2 Feedback Control of FSH.- 2.4 Assays for Inhibin.- 2.4.1 Modified Steelman-Pohley Bioassay.- 2.4.2 Bioassays Using Castrate Rams.- 2.4.3 Bioassays In Vivo Using Rodents.- 2.4.4 In Vitro Bioassays for Inhibin.- 2.5 Assay Specificity.- 2.6 Sources of Inhibin.- 2.7 Evidence for Inhibin from Immunisation Studies.- 2.8 Characteristics and Mode of Action of Inhibin.- 2.9 Physiological Implications of Inhibin.- 2.10 Summary.- 3 Pituitary Testicular Axis During Pubertal Development.- 3.1 Studies in Men.- 3.1.1 Changes During Fetal Life.- 3.1.2 Changes in the Newborn.- 3.1.3 Changes During Childhood and Adolescence.- 3.1.4 Pituitary Responses to LHRH.- 3.2 Studies in Rats.- 3.2.1 Changes in LH, FSH and Testosterone Concentrations with Age.- 3.2.2 Relationship Between Age and Hormonal Levels.- 3.2.3 Changes in Testicular Histology with Age.- 3.2.4 Significance of Hormonal Changes in the Developing Rat.- 3.3 Studies in Rams.- 3.3.1 Changes in FSH, LH, Prolactin and Testosterone Concentrations with Age.- 3.3.2 LH, FSH and Testosterone Responses to LHRH with Age.- 3.3.3 Changes in Testicular Histology with Age.- 3.3.4 Significance of Hormonal Changes.- 3.4 Overall Comments.- 4 Changes in the Pituitary-Testicular Axis with Age.- 4.1 Introduction.- 4.2 Methods.- 4.2.1 Testing the Pituitary-Testicular Axis.- 4.2.2 Selection of Subjects.- 4.2.3 Statistical Methods.- 4.3 Summary of Results.- 4.3.1 Virility, Testicular Size and Histology.- 4.3.2 Gonadotrophin and Sex Hormone Levels.- 4.3.3 Metabolic Clearance and Production Rates of Sex Steroids.- 4.3.4 Dynamic Tests of Gonadotrophin and Testosterone Secretion.- 4.4 Significance of Senescent Testicular Degeneration.- 4.4.1 Mechanism of Hormone Changes with Age.- 4.4.2 Further Studies.- 4.4.3 Aetiology of Testicular Damage.- 4.5 Clinical Relevance.- 4.6 Summary.- 5 Spermatogenesis and the Sertoli Cell.- 5.1 Spermatogenesis.- 5.1.1 The Spermatogenic Cycle.- 5.1.2 Kinetics of the Spermatogenic Process.- 5.1.3 Duration of Spermatogenesis.- 5.1.4 Requirements for Quantitation of Spermatogenesis.- 5.2 The Sertoli Cell.- 5.2.1 Morphological Characteristics.- 5.2.2 Nucleus.- 5.2.3 Cytoplasm.- 5.2.4 Inter-Sertoli Cell Junctions.- 5.2.5 Sertoli Cell Maturation.- 5.2.6 Secretory Products.- 5.2.6.1 Seminiferous Tubule Fluid.- 5.2.6.2 Androgen-Binding Protein.- 5.2.6.3 Inhibin.- 5.2.6.4 Plasminogen Activator.- 5.2.6.5 Other Secretory Products.- 5.2.7 Steroidogenic Activity.- 5.2.8 Hormonal Regulation of Sertoli Cell Function.- 5.2.9 Actions of FSH on the Sertoli Cell.- 5.2.10 Effects of Androgen on the Sertoli Cell.- 5.2.11 Biochemical Changes Associated with Sertoli Cell Maturation.- 6 Leydig Cell Function.- 6.1 Introduction.- 6.2 Morphology of the Leydig Cell.- 6.3 Steroid Biosynthesis and Secretion.- 6.4 Regulation of Leydig Cell Function.- 6.5 Hormonal Regulation of LH Receptors.- 6.5.1 LHRH and Leydig Cell Function.- 6.6 Leydig Cells and Spermatogenesis.- 6.7 Androgens in Blood.- 6.8 Abnormalities of Leydig Cell Function.- 6.8.1 Congenital Disorders.- 6.8.2 Acquired Disorders.- 6.8.2.1 Cirrhosis of the Liver.- 6.8.2.2 Chronic Renal Failure.- 6.8.2.3 Age.- 6.8.3 Testicular Disorders.- 7 The Effect of Testicular Damage on Sertoli and Leydig Cell Function.- 7.1 Introduction.- 7.2 Spermatogenic Damage and the Control of FSH Secretion.- 7.3 Sertoli Cell Function and Testicular Damage.- 7.4 Luteinising Hormone, Testosterone and Spermatogenic Damage.- 7.5 Leydig Cell Structure and Spermatogenic Damage.- 7.6 Leydig Cell Function and Testicular Damage.- References.