AN ASSESSMENT OF THE POSSIBLE ROLE OF 17α,20α-DIHYDROXY-4-PREGNEN-3-ONE IN THE REGULATION OF TESTOSTERONE SYNTHESIS BY RAT AND RABBIT TESTIS

1974 ◽  
Vol 61 (3) ◽  
pp. 401-410 ◽  
Author(s):  
H. W. A. de BRUIJN ◽  
H. J. van der MOLEN
Keyword(s):  
Venous Blood ◽  
Competitive Inhibitor ◽  
Testicular Tissue ◽  
Seminiferous Tubules ◽  
Interstitial Tissue ◽  
Lyase Activity ◽  
Testosterone Biosynthesis

SUMMARY 17α,20α-Dihydroxy-4-pregnen-3-one is a competitive inhibitor of C17,20-lyase activity in rat testicular tissue in vitro and the significance of this inhibition in vitro was evaluated for testosterone biosynthesis in rat and rabbit testis in vivo. It is concluded that 17α,20α-dihydroxy-4-pregnen-3-one is not involved in the regulation of C17,20-activity in vivo, because it was not possible to detect any 17α,20α-dihydroxy-4-pregnen-3-one in rat and rabbit testicular tissue or in testicular venous blood. If present, the levels are lower than 10 pmol/g testis. Levels of 17α-hydroxyprogester-one are in the order of 50 pmol/g testis. The C17,20-lyase has a higher affinity for 17α-hydroxyprogesterone than for 17α,20α-dihydroxy-4-pregnen-3-one and hence inhibition under in-vivo conditions is not favoured. In rat testes the 20α-hydroxysteroid dehydrogenase activity, which can convert 17α-hydroxyprogesterone to 17α,20α-dihydroxy-4-pregnen-3-one, was found to be mainly (97%) localized in the seminiferous tubules and not at the site of testosterone formation in the interstitial tissue.

scholarly journals Overexpression of the Matrix Metalloproteinase Matrilysin Results in Premature Mammary Gland Differentiation and Male Infertility

1998 ◽  
Vol 9 (2) ◽  
pp. 421-435 ◽  
Author(s):  
Laura A. Rudolph-Owen ◽  
Paul Cannon ◽  
Lynn M. Matrisian
Keyword(s):  
Matrix Metalloproteinase ◽  
Transgenic Animals ◽  
Reproductive Organs ◽  
Mammary Development ◽  
Seminiferous Tubules ◽  
Interstitial Tissue ◽  
Wild Type ◽  
The Matrix

To examine the role of matrilysin (MAT), an epithelial cell-specific matrix metalloproteinase, in the normal development and function of reproductive tissues, we generated transgenic animals that overexpress MAT in several reproductive organs. Three distinct forms of human MAT (wild-type, active, and inactive) were placed under the control of the murine mammary tumor virus promoter/enhancer. Although wild-type, active, and inactive forms of the human MAT protein could be produced in an in vitro culture system, mutations of the MAT cDNA significantly decreased the efficiency with which the MAT protein was produced in vivo. Therefore, animals carrying the wild-type MAT transgene that expressed high levels of human MAT in vivo were further examined. Mammary glands from female transgenic animals were morphologically normal throughout mammary development, but displayed an increased ability to produce β-casein protein in virgin animals. In addition, beginning at approximately 8 mo of age, the testes of male transgenic animals became disorganized with apparent disintegration of interstitial tissue that normally surrounds the seminiferous tubules. The disruption of testis morphology was concurrent with the onset of infertility. These results suggest that overexpression of the matrix-degrading enzyme MAT alters the integrity of the extracellular matrix and thereby induces cellular differentiation and cellular destruction in a tissue-specific manner.

P–056 To graft or not to graft? Intratesticular grafting of testicular tissue from Klinefelter boys to the mouse testis as possible novel in vivo model

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
M Willems ◽  
P Sesenhausen ◽  
I Gies ◽  
V Vloeberghs ◽  
J D Schepper ◽  
...  
Keyword(s):  
Klinefelter Syndrome ◽  
Testicular Biopsy ◽  
Testicular Tissue ◽  
Mouse Testis ◽  
In Vivo Model ◽  
Seminiferous Tubules ◽  
Positive Effects ◽  
Fibrotic Process

Abstract Study question Can intratesticular transplanted testis tissue from Klinefelter boys to the mouse testis be used to study the mechanisms behind testicular fibrosis? Summary answer Grafting of testicular tissue from Klinefelter boys to the mouse testis is not a valuable new in vivo model to study Klinefelter-related testicular fibrosis. What is known already Klinefelter syndrome (KS; 47, XXY) affects 1–2 in 1000 males. Most KS men suffer from azoospermia due to a loss of spermatogonial stem cells. Additionally, testicular fibrosis is detected from puberty onwards. However, mechanisms responsible for fibrosis and germ cell loss remain unknown. An optimal in vivo model to study the KS testicular fibrotic process is not available. This study aimed to evaluate a possible in vivo model to study KS-related testicular fibrosis. In addition, the effect of the mast cell blocker ketotifen, which showed positive effects on fertility in infertile non-KS patients, was evaluated in this graft model. Study design, size, duration First, the survival time of the KS graft was established, since it was the first time KS tissue was transplanted to the mouse testis. Testes were collected after two, four, six and eight weeks after which histological and immunohistochemical evaluations were performed. Next, the effect of daily ketotifen injections on the fibrotic appearance of intratesticular grafted testicular tissue from KS and controls was evaluated. Participants/materials, setting, methods Testicular biopsy samples from pre- and peripubertal KS (n = 22) and age-matched control samples (n = 22) were transplanted to the testes of six weeks old Swiss Nu/Nu mice (n = 22). Prior to grafting, testicular tissue pieces were cultured in vascular endothelial growth factor (VEGF) for five days. Next, tissues were transplanted to the mouse testes. Testicular transplants were analysed by immunohistochemistry. In the second experiment, mice were given daily subcutaneous injections of ketotifen or saline. Main results and the role of chance Four weeks after transplantation, all KS grafts could still be retrieved. At a later timepoint, degeneration of the tissue could be detected. In the grafts, recovered four weeks after transplantation, about 30% of the tubules in peripubertal grafts showed a good integrity, while in the prepubertal tissue, 83% of the tubules were intact. A fibrotic score was assigned to each graft. No significant changes in fibrotic score was observed between testicular biopsies before or after transplantation. However, an increased (p < 0.01) fibrotic score was observed after in-vitro treatment with VEGF both in control and KS tissue. Based on recovery and tubule integrity grafts were recovered after four weeks in the second experiment. Treatment with ketotifen did not result in significant histological differences compared to non-treated grafts (KS and control tissue). The survival potential of grafts from KS testicular biopsies of pre- and peripubertal boys was patient- and age-dependent. After four weeks, most KS tissue starts to degenerate. In prepubertal tissue, seminiferous tubules were mostly intact, while tissue from adolescent boys was impaired. Interestingly, no loss of germ cells was observed after transplantation of the testicular tissue. Limitations, reasons for caution The availability of tissue from young KS patients is very scarce, leading to a low number of included patients (n = 8). Testicular tissue pieces from the same patient were included to evaluate the differences before and after transplantation. However, histological variability between testicular tissue biopsy pieces is well-known in KS patients. Wider implications of the findings Since testicular tissue from KS boys, transplanted to the mouse testes, already starts to degenerate after four weeks and the integrity is not optimal, we conclude that this is not a valuable model for future studies. In vitro models to study the KS-testicular fibrosis should be investigated. Trial registration number NA

Characterization of the reproductive effects of the anorexigenic VGF-derived peptide TLQP-21: in vivo and in vitro studies in male rats

2011 ◽  
Vol 300 (5) ◽  
pp. E837-E847 ◽  
Author(s):  
Leonor Pinilla ◽  
Rafael Pineda ◽  
Francisco Gaytán ◽  
Magdalena Romero ◽  
David García-Galiano ◽  
...  
Keyword(s):  
Chronic Administration ◽  
Testicular Tissue ◽  
Male Rats ◽  
Central Administration ◽  
Adult Males ◽  
Hpg Axis ◽  
Reproductive Effects

VGF (nonacronymic) is a 68-kDa protein encoded by the homonymous gene, which is expressed abundantly at the hypothalamus and has been involved in the control of metabolism and body weight homeostasis. Different active peptide fragments are generated from VGF, including TLQP-21. Circumstantial evidence has suggested that VGF might also participate in the control of reproduction. Yet its mechanisms of action and the eventual role of specific VGF-derived peptides on the hypothalamic-pituitary-gonadal (HPG) axis remain unknown. Herein we report a series of studies on the reproductive effects of TLQP-21 as evaluated in male rats by a combination of in vivo and in vitro analyses. Central administration of TLQP-21 induced acute gonadotropin responses in pubertal and adult male rats, likely via stimulation of GnRH secretion, as documented by static incubations of hypothalamic tissue. In addition, in pubertal (but not adult) males, TLQP-21 stimulated LH secretion directly at the pituitary level. Repeated central administration of TLQP-21 to pubertal males subjected to chronic undernutrition was able to ameliorate the hypogonadotropic state induced by food deprivation. In contrast, chronic administration of TLQP-21 to fed males at puberty resulted in partial desensitization and puberty delay. Finally, in adult (but not pubertal) males, TLQP-21 enhanced hCG-stimulated testosterone secretion by testicular tissue in vitro. In summary, our data are the first to document a complex and multifaceted mode of action of TLQP-21 at different levels of the male HPG axis with predominant stimulatory effects, thus providing a tenable basis for the (direct) reproductive role of this VGF-derived peptide.

OESTRADIOL-17β AND TESTOSTERONE IN RAT TESTIS TISSUE: EFFECT OF GONADO-TROPHINS, LOCALIZATION AND PRODUCTION IN VITRO

1974 ◽  
Vol 60 (3) ◽  
pp. 409-419 ◽  
Author(s):  
F. H. de JONG ◽  
A. H. HEY ◽  
H. J. van der MOLEN
Keyword(s):  
Intravenous Injection ◽  
Testicular Tissue ◽  
Prolonged Treatment ◽  
Seminiferous Tubules ◽  
Interstitial Tissue ◽  
Tissue Concentrations ◽  
Hypophysectomized Rats ◽  
Trophic Hormone ◽  
Testis Tissue

SUMMARY Concentrations of oestradiol-17β and testosterone were estimated in testicular tissue from intact and hypophysectomized rats. Within 30 min after intravenous injection of human chorionic gonadotrophin (HCG) or follicle-stimulating hormone (FSH) to intact animals the tissue concentrations of both steroids were not significantly changed. Prolonged s.c. administration of HCG (5 days) caused an increase in the tissue levels of both steroids, which was further increased when the prolonged treatment was followed by an intravenous injection with this trophic hormone. FSH had no influence on tissue concentrations of oestradiol-17β or testosterone in hypophysectomized rats. Assay of separated seminiferous tubules and interstitial tissue indicated that oestradiol-17β and testosterone were mainly localized in the interstitial tissue. Incubations of these constituents showed that oestradiol-17β was produced in the seminiferous tubules, while testosterone was produced in the interstitial compartment.

scholarly journals Microfluidic bioprinting for the in vitro generation of novel biomimetic human testicular tissues

2021 ◽  
Author(s):  
Meghan Alice Robinson ◽  
Erin Bedford ◽  
Luke Witherspoon ◽  
Stephanie Willerth ◽  
Ryan Flannigan
Keyword(s):  
Cancer Survival ◽  
Fertility Restoration ◽  
Survival Rates ◽  
Testicular Tissue ◽  
Seminiferous Tubules ◽  
Vitro Fertilization ◽  
Testicular Cells ◽  
Human Spermatogenesis

Advances in cancer treatments have greatly improved pediatric cancer survival rates, leading to quality of life considerations and in particular fertility restoration. Accordingly, pre-pubertal patients have the option to cryopreserve testicular tissue for experimental restorative therapies, including in vitro spermatogenesis, wherein testicular tissue is engineered in vitro and spermatozoa are collected for in vitro fertilization (IVF). Current in vitro systems have been unable to reliably support the generation of spermatozoa from human testicular tissues, likely due to the inability for the dissociated testicular cells to recreate the native architecture of testicular tissue found in vivo. Recent advances in 3-D bioprinting can place cells into geometries at fine resolutions comparable to microarchitectures found in native tissues, and therefore hold promise as a tool for the development of a biomimetic in vitro system for human spermatogenesis. This study assessed the utility of bioprinting technology to recreate the precise architecture of testicular tissue and corresponding spermatogenesis for the first time. We printed testicular cell-laden hollow microtubules at similar resolutions to seminiferous tubules, and compared the results to testicular organoids. We show that the human testicular cells retain their viability and functionality post-printing, and illustrate an intrinsic ability to reorganize into their native cytoarchitecture. This study provides a proof of concept for the use of 3-D bioprinting technology as a tool to create biomimetic human testicular tissues.

ROLE OF DEHYDROEPIANDROSTERONE AND ITS SULPHATE IN SYNTHESIS OF TESTOSTERONE BY HUMAN TESTES IN VIVO AND IN VITRO

1970 ◽  
Vol 46 (1) ◽  
pp. 21-28 ◽  
Author(s):  
M. C. RAHEJA ◽  
O. J. LUCIS
Keyword(s):  
Free Testosterone ◽  
Testicular Tissue ◽  
Dehydroepiandrosterone Sulphate ◽  
Venous Plasma

SUMMARY The synthesis of testosterone from [4-14C]dehydroepiandrosterone (DHEA) and [7α-3H]dehydroepiandrosterone sulphate (DHEA-S) by human testes in vivo and in vitro was investigated. Neither free testosterone nor free DHEA was found in a perfused testis or the spermatic venous plasma after the infusion of [7α-3H]DHEA-S into the spermatic artery in vivo, whereas 3H-labelled free DHEA, testosterone and androstenedione were isolated after incubation of testicular tissue with the same substrate in vitro. Only 14C-labelled testosterone was found in the spermatic venous effluent and in the testis after infusion of a mixture of equimolar amounts of [7α-3H]-DHEA-S and [4-14C]DHEA into the spermatic artery in vivo. Testosterone containing 3H and 14C was isolated after incubation of testicular tissue with a mixture of the two substrates in vitro.

Defective spermatogenesis and testosterone levels in kinase suppressor of Ras1 (KSR1)-deficient mice

2019 ◽  
Vol 31 (8) ◽  
pp. 1369
Author(s):  
Elena Moretti ◽  
Giulia Collodel ◽  
Giuseppe Belmonte ◽  
Daria Noto ◽  
Emanuele Giurisato
Keyword(s):  
Molecular Mechanisms ◽  
Sperm Concentration ◽  
Testicular Tissue ◽  
Seminiferous Tubules ◽  
Interstitial Tissue ◽  
Testosterone Levels ◽  
Transmission Electron ◽  
Human Spermatogenesis ◽  
Testis Tissue

The aim of this study was to clarify the role of the protein kinase suppressor of Ras1 (KSR1) in spermatogenesis. Spermatogenesis in ksr1−/− mice was studied in testicular tissue and epididymal spermatozoa by light and transmission electron microscopy and by immunofluorescence using antibodies to ghrelin and 3β-hydroxysteroid dehydrogenase (3β-HSD). Blood testosterone levels were also assessed. ksr1−/− mice showed reduced epididymal sperm concentration and motility as compared with wild-type (wt) mice. Testis tissue from ksr1−/− mice revealed a prevalent spermatogenetic arrest at the spermatocyte stage; the interstitial tissue was hypertrophic and the cytoplasm of the Leydig cells was full of lipid droplets. Ghrelin signal was present in the seminiferous tubules and, particularly, in the interstitial tissue of wt mice; however, in ksr1−/− mice ghrelin expression was very weak in both the interstitial tissue and tubules. On the contrary, the signal of 3β-HSD was weak in the interstitial tissue of wt and strong in ksr1−/− mice. Testosterone levels were significantly increased in the blood of ksr1−/− mice (P<0.05) as compared with wt. The results obtained reveal the importance of the KSR scaffold proteins in the spermatogenetic process. The study of the molecular mechanisms associated with spermatogenetic defects in a mouse model is essential to understand the factors involved in human spermatogenesis.

EFFECTS OF PITUITARY HORMONES ON PROGESTATIONAL HORMONE PRODUCTION BY THE RABBIT OVARY IN VIVO AND IN VITRO

1966 ◽  
Vol 35 (1) ◽  
pp. 53-63 ◽  
Author(s):  
J. H. DORRINGTON ◽  
R. KILPATRICK
Keyword(s):  
Ovarian Tissue ◽  
Venous Blood ◽  
Interstitial Tissue ◽  
Corpora Lutea ◽  
Hormone Production ◽  
Stimulatory Action ◽  
Steroid Synthesis ◽  
Ovine Prolactin

SUMMARY Ovine luteinizing hormone (LH) increased the output of progestational steroids (20α-hydroxypregn-4-en-3-one and progesterone) in rabbit ovarian venous blood. Similar increases were found with ovine follicle-stimulating hormone (FSH) and growth hormone, but much larger amounts were necessary. Ovine prolactin was without effect. The increased output was due to increased synthesis and not only to release of stored steroids. Synthesis of these progestational steroids was stimulated by LH incubated with rabbit ovarian tissue. The stimulation produced by FSH was probably due to contamination by LH since the log dose-response lines for LH and FSH were parallel, and FSH was approximately 100 times less active than LH. Ovine prolactin had no stimulatory activity in concentrations up to 20 μg./ml. The stimulatory action of LH was unrelated to the presence of corpora lutea. Separated corpora lutea showed only a slight response to LH, whereas the response of interstitial tissue was similar to that found with undissected ovaries. Hence LH caused progestational steroid synthesis by stimulating the ovarian interstitial tissue.

scholarly journals The C-X-C signalling system in the rodent vs primate testis: impact on germ cell niche interaction

Reproduction ◽  
2018 ◽  
Vol 155 (5) ◽  
pp. R211-R219 ◽  
Author(s):  
Laura Heckmann ◽  
Tim Pock ◽  
Ina Tröndle ◽  
Nina Neuhaus
Keyword(s):  
Germ Cell ◽  
Transmembrane Domain ◽  
Basal Membrane ◽  
Seminiferous Tubules ◽  
Testicular Development ◽  
Signalling System ◽  
Evolutionarily Conserved

In zebrafish, action of the chemokine Cxcl12 is mediated through its G-protein-coupled seven-transmembrane domain receptor Cxcr4 and the atypical receptor Cxcr7. Employing this animal model, it was revealed that this Cxcl12 signalling system plays a crucial role for directed migration of primordial germ cells (PGC) during early testicular development. Importantly, subsequent studies indicated that this regulatory mechanism is evolutionarily conserved also in mice. What is more, the functional role of the CXCL12 system does not seem to be limited to early phases of testicular development. Data from mouse studies rather demonstrate that CXCL12 and its receptors are also involved in the homing process of gonocytes into their niches at the basal membrane of the seminiferous tubules. Intriguingly, even the spermatogonial stem cells (SSCs) present in the adult mouse testis appear to maintain the ability to migrate towards a CXCL12 gradient as demonstrated by functional in vitro migration assays and in vivo germ cell transplantation assays. These findings not only indicate a role of the CXCL12 system throughout male germ cell development in mice but also suggest that this system may be evolutionarily conserved. In this review, we take into account the available literature focusing on the localization patterns of the CXCL12 system not only in rodents but also in primates, including the human. Based on these data, we discuss whether the CXCL12 system is also conserved between rodents and primates and discuss the known and potential functional consequences.

Studies on the Regulatory Role of trans-Cinnamic Acid on the Activity of the Phenylalanine Ammonia-Lyase (PAL) in Suspension Cultures of Daucus carota L.

1983 ◽  
Vol 38 (5-6) ◽  
pp. 408-412 ◽  
Author(s):  
W. Noé ◽  
H. U. Seitz
Keyword(s):  
Protein Synthesis ◽  
Cinnamic Acid ◽  
Phenylalanine Ammonia Lyase ◽  
Competitive Inhibitor ◽  
Regulatory Role ◽  
Coumaric Acid ◽  
Daucus Carota L

In vivo and in vitro experiments were performed in order to study the regulatory role of trans- cinnamic acid and its hydroxylated derivatives (p-coumaric acid, caffeic acid) on the deamina­tion of phenylalanine catalyzed by PAL (EC 4.3.1.5). Trans-cinnamic acid inhibits growth and reduces the content of soluble proteins of anthocyanin-containing carrot cells grown in suspen­sion. There is strong evidence from the polysomal patterns and from the effect of trans-cinnamic acid on protein synthesis in vitro that protein synthesis is inhibited. The kinetic data of PAL clearly demonstrate that trans-cinnamic acid inhibits the enzyme by a noncompetitive mecha­nism. On the contrary, ʟ-α-aminooxy-β-phenylpropionic acid (ʟ-AOPP), a competitive inhibitor of PAL, does not affect protein metabolism.

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