Growth factors as autocrine and paracrine modulators of male gonadal functions

Bellvé, Anthony R.; Zheng, Wenxin

doi:10.1530/jrf.0.0850771

Cited by 156 publications

(44 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Myoid cells (peritubular cells) surround the seminiferous epithelium and define the outer limits of seminiferous tubules. Myoid cells, like Sertoli cells and Leydig cells, are influenced by testicular growth factors (Bellve and Zheng, 1989). In addition to myoid cells, the tubular boundary tissue contains a relatively thick (visible at the light microscopic level) basal lamina and collagen elastic fibrils.…”

Section: Composition Of Seminiferous Tubules Somatic Cells: Sertoli Cmentioning

confidence: 99%

“…Sertoli cells (SC), myoid cells (MC), Leydig cells (LC), a newly developing flagellum (F), the annulus (An), manchette tids, movement of young germ cells, phagocytosis of degenerating germ cells and residual bodies left by released spermatozoa, secretion of luminal fluid and proteins, formation of the blood-testis barrier, and cell to cell communication (de Kretser and Kerr, 1988;Dym and Madhwa Raj, 1977). The Sertoli cell secretes lactate (Jutte et al, 1982, 19831, and mitogenic polypeptides (Bellve and Zheng, 1989;Buch et al, 1988;Feig et al, 1980;Tres et al, 1986). Lactate is a necessary energy source for germ cells.…”

Section: Composition Of Seminiferous Tubules Somatic Cells: Sertoli Cmentioning

confidence: 99%

See 1 more Smart Citation

Efficiency of spermatogenesis

Johnson

1995

Microscopy Res & Technique

View full text Add to dashboard Cite

Spermatogenesis is a process of division and differentiation by which spermatozoa are produced in seminiferous tubules. A measure of efficiency of spermatogenesis is the estimated number of spermatozoa produced per day per gram of testicular parenchyma. This measure is not influenced by species differences in testicular size; however, it is influenced by species differences in the numerical density of germ cells and in the life spans of these cells. Seminiferous tubules are composed of somatic cells (myoid cells and Sertoli cells), and germ cells (spermatogonia, spermatocytes, and spermatids). Activity of these three germ cells divide spermatogenesis into spermatocytogenesis, meiosis, and spermiogenesis, respectively. Spermatocytegenesis involves mitotic cell division to increase the yield of spermatogenesis and to produce stem cells and primary spermatocytes. Meiosis involves duplication and exchange of genetic material and two cell divisions that reduce the chromosome number and yield four spermatids. Spermiogenesis is the differentiation of spherical spermatids into mature spermatids which are released at the luminal free surface as spermatozoa. The spermatogenic cycle is superimposed on the three major divisions of spermatogenesis. Spermatogenesis and germ cell degeneration can be quantified from numbers of germ cells in various steps of development throughout spermatogenesis, and quantitative measures are related to number of spermatozoa in the ejaculate. Germ cell degeneration occurs throughout spermatogenesis; however, the greatest impact occurs during spermatocytogenesis and meiosis. Efficiency of spermatogenesis is related to the amount of germ cell degeneration, pubertal development, season of the year, and aging of humans and animals. Number of Sertoli cells and amount of smooth endoplasmic reticulum of Leydig cells (but not Leydig cell number) are related to efficiency of spermatogenesis. In humans, efficiency of spermatogenesis is reflected in number of spermatogenic stages per cross-section and number of missing generations within each stage; however, the arrangement of stages along the tubular length does not reflect differences in the efficiency of spermatogenesis. In short, spermatogenesis involves both mitotic and meiotic cell divisions and an unsurpassed example of cell differentiation in the production of the spermatozoon, and daily sperm production per g parenchyma is a measure of its efficiency.

show abstract

Section: Composition Of Seminiferous Tubules Somatic Cells: Sertoli Cmentioning

confidence: 99%

Section: Composition Of Seminiferous Tubules Somatic Cells: Sertoli Cmentioning

confidence: 99%

Efficiency of spermatogenesis

Johnson

1995

Microscopy Res & Technique

View full text Add to dashboard Cite

show abstract

“…Since testosterone levels in BG-jsdljsd males were normal a t all ages examined, the LHiLeydig cell axis should be normal (Beamer et al, 1988). However, we have no information concerning about the other functions of Leydig cells such as the production of some factors which may play a role, such as paracrine growth factors in germ cell differentiation (Sharpe, 1982;Bellve and Zheng, 1989).…”

Section: Discuss I 0 Nmentioning

confidence: 99%

Loss of sperm in juvenile spermatogonial depletion (jsd) mutant mice is ascribed to a defect of intratubular environment to support germ cell differentiation

Mizunuma

Dohmae

Tajima

et al. 1992

Journal Cellular Physiology

View full text Add to dashboard Cite

C57BL/6(B6)-jsd/jsd mice are sterile due to the defective spermatogenesis in the testes. To know the cause of the deficient spermatogenesis in B6-jsd/jsd mice, we examined whether the problem is within or outside the seminiferous tubules by transplanting tubules from cryptorchid testes of B6- +/+ mice into B6-jsd/jsd testes or tubules from B6-jsd/jsd mice into testes of (WB x C57BL/6)F1-W/Wv (hereafter, WBB6F1-W/Wv) mice. Type A spermatogonia differentiated into spermatids in seminiferous tubules from cryptorchid testes transplanted into B6-jsd/jsd testes. In contrast, in B6-jsd/jsd tubules transplanted into WBB6F1-W/Wv testes, type A spermatogonia were stimulated to mitotic proliferation, but didn't proceed to any differentiated germ cells. The present results suggest that the cause of the deficient spermatogenesis in B6-jsd/jsd mice is a defect of intratubular environment to support germ cell differentiation.

show abstract

“…Since the first report of the presence of a mitogenic substance in the mammalian testis [ 141, a number of studies have sought to identify putative testicular growth factors and to understand the physiologic role of these factors in the paracrine regulation of spermatogenesis [2,3,7,14,16,271. To date many of the known growth factors, including fibroblast growth factors, nerve growth factors, insulinlike growth factors (IGFs), and transforming growth factors, have been identified in the testis of various species [21,23,25,271 or Sertoli cell culture medium [6, 241.…”

Section: Discussionmentioning

confidence: 99%

Ontogeny of Rat Testicular Mitogenic Activity Studied with Transformed and Nontransformed Mouse 3T3 Fibroblasts

Searle

Pogach²,

Nathan³

et al. 1990

Archives of Andrology

View full text Add to dashboard Cite

The ontogeny of the testicular mitogenic activity of Sprague Dawley rats was evaluated by stimulation in vitro of [3H]thymidine uptake and cell number in Swiss 3T3 and transformed NIH 3T3 fibroblasts. Addition of various amounts of testicular cytosolic protein resulted in a dose-dependent increase in cell number in both cell lines. The [3H]thymidine responses to testicular cytosolic proteins was also dose dependent but in a nonparametric manner. In addition, the responses of 3T3 cells to testicular cytosol was apparently dependent on the developmental stage of the testis, the time of stimulation, and the proliferative nature of the fibroblast cell line. These results suggest the presence of multiple forms of mitogenic substance in testicular cytosol and imply that the relative amounts of these substances may depend on the age of the donor animal. These substances may be important in the proliferation or differentiation of cell types at various stages of testicular development.

show abstract

Growth factors as autocrine and paracrine modulators of male gonadal functions

Cited by 156 publications

References 78 publications

Efficiency of spermatogenesis

Efficiency of spermatogenesis

Loss of sperm in juvenile spermatogonial depletion (jsd) mutant mice is ascribed to a defect of intratubular environment to support germ cell differentiation

Ontogeny of Rat Testicular Mitogenic Activity Studied with Transformed and Nontransformed Mouse 3T3 Fibroblasts

Contact Info

Product

Resources

About