Quantitative analysis of germ cell numbers and relation to intratesticular testosterone following vitamin A-induced synchronization of spermatogenesis in the rat

1989 ◽  
Vol 123 (3) ◽  
pp. 403-NP ◽  
Author(s):  
J. M. S. Bartlett ◽  
G. F. Weinbauer ◽  
E. Nieschlag
Keyword(s):  
Quantitative Analysis ◽  
Vitamin A ◽  
Germ Cell ◽  
Time Course ◽  
Serum Testosterone ◽  
Seminiferous Tubules ◽  
Ideal Model ◽  
Paracrine Factors ◽  
Cell Numbers ◽  
Pachytene Spermatocytes

ABSTRACT Synchronization of spermatogenesis would provide an ideal model for the investigation of stage-dependent changes in the secretion of paracrine factors. In vitamin A-deficient animals subsequently injected with vitamin A, over 80% of seminiferous tubules were synchronized within three to five stages of the seminiferous cycle. Following replenishment of vitamin A, spermatogenic stages IV–VI (35 days), VI–VIII (38 days), IX–XII (41 days), I–IV (45 days) and V–VII (48 days) were observed. Despite synchronization of spermatogenesis at all stages, spermatogenesis was markedly impaired when evaluated in a quantitative fashion. At all times evaluated, numbers of round spermatids were reduced compared with age-matched controls. Numbers of pachytene spermatocytes reached control values only after 45 days of vitamin A replenishment. Elongate spermatids were almost totally absent up to 41 days after vitamin A replenishment. Testicular and epididymal weights were also reduced, although testicular weights showed a significant recovery over the time-course of the study. Serum and pituitary concentrations of LH and FSH were raised at the commencement of the study, with serum gonadotrophins returning to control values 48 days after vitamin A replenishment. Both testicular and serum testosterone concentrations in treated animals tended to be higher than in the controls. Although synchronization of spermatogenesis was achieved, testicular testosterone concentrations did not reflect the stage-dependent cyclical changes observed in earlier studies. Testicular concentrations of testosterone were raised throughout the period of observation with the exception of animals synchronized around stages II–IV of the spermatogenic cycle. No correlation between the most frequent stages and intratesticular testosterone was found (r = 0·06, P > 0·1). Previous observations that testosterone concentrations are selectively increased at stages VII–VIII of the spermatogenic cycle are not supported by the present study. Journal of Endocrinology (1989) 123, 403–412

scholarly journals Testosterone immunoreactivity in the seminiferous epithelium of rat testis: effect of treatment with ethane dimethanesulfonate.

1989 ◽  
Vol 37 (11) ◽  
pp. 1667-1673 ◽  
Author(s):  
R Schulz ◽  
F Paris ◽  
P Lembke ◽  
V Blüm
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Time Course ◽  
Seminiferous Epithelium ◽  
Male Rats ◽  
Plasma Testosterone ◽  
Seminiferous Tubules ◽  
Treatment Level ◽  
Cell Nuclei ◽  
Testicular Weight

Androgens drive spermatogenesis by processes that are largely unknown. Direct effects on germ cells and indirect effects mediated via testicular somatic elements are currently under consideration, and specific localization of androgens in seminiferous tubules may provide information as regards this. Adult male rats were injected with ethane dimethanesulfonate (EDS; 75 mg/kg body weight) or vehicle. Testes were fixed and paraffin-embedded for localization of testosterone immunoreactivity 1 and 2 weeks after treatment, using the unlabeled antibody (PAP) technique. Plasma testosterone dropped from a pre-treatment level of 2.3 ng/ml to below 0.2 ng/ml 3 days after EDS injection and remained at low levels until the end of observation, accompanied by a progressive decrease in testicular weight. In the seminiferous tubules of vehicle-injected males, testosterone immunoreactivity was found in nuclei of spermatocytes and spermatids and in nuclei and the cytoplasm of Sertoli cells, and showed typical variations according to the stage of spermatogenesis. One week after EDS treatment, immunoreactivity had disappeared from the seminiferous epithelium. Two weeks after treatment, staining of germ cells was detected in two out of four males. The disappearance and reappearance of immunoreactivity coincided with the time course of EDS effects on rat Leydig cells, and we conclude that it corresponds to androgen specifically localized in fixed, paraffin-embedded tissue. Because staining of germ cell nuclei varied with the stage of spermatogenesis, the technique may detect a physiologically relevant androgen fraction; its location suggests that androgens may also directly affect certain germ cell stages.

scholarly journals Rat spermatogenesis in vitro traced by quantitative flow cytometry.

1986 ◽  
Vol 34 (8) ◽  
pp. 1029-1035 ◽  
Author(s):  
J Toppari ◽  
P Mali ◽  
E Eerola
Keyword(s):  
Flow Cytometry ◽  
Morphological Differentiation ◽  
Culture Conditions ◽  
Seminiferous Tubules ◽  
Dna Flow Cytometry ◽  
Cell Numbers ◽  
Pachytene Spermatocytes ◽  
Quantitation Method ◽  
Rat Spermatogenesis

In vitro differentiation of germ cells in rat seminiferous tubule segments at stages II-III of the epithelial cycle was studied. DNA flow cytometry was used for quantitation of absolute cell numbers from the cultured tubule segments that were compared to freshly isolated stages of the cycle, as identified by transillumination stereomicroscopy of the seminiferous tubules and phase-contrast microscopy of live cell squashes. Spermatogonia and spermatocytes from stages II-III showed normal morphological differentiation during 7 days in vitro. Round spermatids differentiated to Step 7 of spermiogenesis but Step 16 spermatids failed to develop. Acid phosphatase activity in the spermatogenic cells changed normally during the culture. As compared with freshly isolated control tubule segments, 35% of round spermatids and 42% of pachytene spermatocytes were present in culture after 7 days. The cell numbers recovered from defined stages by DNA flow cytometry were close to those found in morphometric studies. Flow cytometry is an efficient quantitation method for cells liberated from seminiferous epithelium. Spermatogonia, spermatocytes, and early spermatids are able to differentiate in vitro, but spermatids approaching the elongation (acrosome) phase, and particularly the maturation phase, fail to differentiate under present culture conditions.

scholarly journals Gonadal status of male recipient mice influences germ cell development in immature buffalo testis tissue xenograft

Reproduction ◽  
2012 ◽  
Vol 143 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Niranjan Reddy ◽  
Ranjeet Singh Mahla ◽  
Revanth Thathi ◽  
Sanjay Kumar Suman ◽  
Jedy Jose ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Germ Cell ◽  
Germ Cells ◽  
Serum Testosterone ◽  
Intact Mouse ◽  
Germ Cell Differentiation ◽  
Pachytene Spermatocytes ◽  
Gonadal Status ◽  
Tubule Diameter ◽  
Testis Tissue

Growth and development of immature testis xenograft from various domestic mammals has been shown in mouse recipients; however, buffalo testis xenografts have not been reported to date. In this study, small fragments of testis tissue from 8-week-old buffalo calves were implanted subcutaneously onto the back of immunodeficient male mouse recipients, which were either castrated or left intact (non-castrated). The xenografts were retrieved and analyzed 12 and 24 weeks later. The grafted tissue survived and grew in both types of recipient with a significant increase in weight and seminiferous tubule diameter. Recovery of grafts from intact recipients 24 weeks post-grafting was significantly lower than that from the castrated recipients. Seminal vesicle indices and serum testosterone levels were lower in castrated recipients at both collection time points in comparison to the intact recipients and non-grafted intact mouse controls. Pachytene spermatocytes were the most advanced germ cells observed in grafts recovered from castrated recipients 24 weeks post-grafting. Complete spermatogenesis, as indicated by the presence of elongated spermatids, was present only in grafts from intact recipients collected 24 weeks post-grafting. However, significant number of germ cells with DNA damage was also detected in these grafts as indicated by TUNEL assay. The complete germ cell differentiation in xenografts from intact recipients may be attributed to efficient Sertoli cell maturation. These results suggest that germ cell differentiation in buffalo testis xenograft can be completed by altering the recipient gonadal status.

Maintenance of complete but quantitatively reduced spermatogenesis in hypophysectomized monkeys by testosterone alone

1986 ◽  
Vol 113 (3) ◽  
pp. 424-431 ◽  
Author(s):  
G. R. Marshall ◽  
F. Jockenhövel ◽  
D. Lüdecke ◽  
E. Nieschlag
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Serum Testosterone ◽  
Serum Levels ◽  
Testicular Volume ◽  
Cynomolgus Monkeys ◽  
Cell Numbers ◽  
Pituitary Ablation ◽  
Complete Process ◽  
Spermatogonial Proliferation

Abstract. In order to investigate whether testosterone can maintain spermatogenesis in the absence of FSH in primates, four cynomolgus monkeys were hypophysectomized and implanted with 20 5-cm-long testosteronefilled silastic capsules within 45 min of pituitary ablation. Thereafter the serum levels of testosterone were elevated about 9-fold over presurgical levels. Testicular volumes declined to 60% of presurgical values. Testicular concentrations of testosterone were 50–180% of presurgical levels. Germ cell numbers were reduced to 30–50% of presurgical values and germ cell ratios suggested that the reduced numbers of all advanced germ cells were due to a decrease in the efficiency of proliferation of B spermatogonia. A fifth monkey was left untreated following hypophysectomy. Its serum testosterone was as low as that of castrated monkeys, and the testicular volume declined to 30% of that before surgery. Primitive spermatogonia were the only germ cells present 13 weeks after surgery. Thus, in primates testosterone alone maintains the complete process of spermatogenesis, however, spermatogonial proliferation is impaired in the absence of FSH.

scholarly journals Testicular parameters and spermatogenesis in different birthweight boars

2017 ◽  
Vol 29 (9) ◽  
pp. 1720 ◽  
Author(s):  
P. A. Auler ◽  
G. H. F. A. Moreira ◽  
C. O. Hogg ◽  
C. J. Ashworth ◽  
F. P. Bortolozzo ◽  
...  
Keyword(s):  
Germ Cell ◽  
The Other ◽  
Testicular Development ◽  
Sperm Production ◽  
Relative Expression ◽  
Cell Numbers ◽  
Pachytene Spermatocytes ◽  
Neonatal Testis ◽  
Daily Sperm Production

The present study investigated the effect of birthweight on testicular development and spermatogenesis in boars. Twenty-four pairs of littermate boars were selected: one piglet with the highest birthweight (HW) and the other with the lowest birthweight (LW) within the litter. Two subsets of 12 pairs of male littermates from each birthweight group were obtained after selection: one subset was orchiectomised at 8 days and the other at 8 months of age. HW boars had higher body and testicular weights at both ages (P < 0.05). Testosterone concentrations and the relative expression of 17α-hydroxylase in the testis were similar between birthweight groups. Birthweight affected somatic and germ cell numbers in the neonatal testis, which were higher in HW boars (P < 0.05). Moreover, a significant reduction in the number of pachytene spermatocytes and round spermatids was observed in LW boars (P < 0.05) at 8 months of age, which caused a decrease in the total number of elongated spermatids and daily sperm production (P < 0.05). Hence, HW boars have the potential to produce more spermatozoa and consequently more semen doses per ejaculate, and would be very valuable to an industry that relies on AI.

scholarly journals Sertoli and Germ Cell Development in Hypogonadal (hpg) Mice Expressing Transgenic Follicle-Stimulating Hormone Alone or in Combination with Testosterone

Endocrinology ◽  
2003 ◽  
Vol 144 (2) ◽  
pp. 509-517 ◽  
Author(s):  
Miriam Haywood ◽  
Jenny Spaliviero ◽  
Mark Jimemez ◽  
Nicholas J. C. King ◽  
David J. Handelsman ◽  
...  
Keyword(s):  
Germ Cell ◽  
Sertoli Cell ◽  
Synergistic Effects ◽  
Cell Development ◽  
Seminiferous Tubules ◽  
Germ Cell Development ◽  
Cell Numbers ◽  
Meiotic Progression ◽  
Spermatogonial Proliferation

We recently created a novel transgenic (tg) model to examine the specific gonadal actions of FSH, distinct from LH effects, by expressing tg-FSH in gonadotropin-deficient hypogonadal (hpg) mice. Using this unique in vivo paradigm, we now describe the postnatal cellular development in seminiferous tubules selectively stimulated by tg-FSH alone or combined with testosterone (T). In the αβ.6 line, tg-FSH stimulated the maturation and proliferation (∼2-fold) of Sertoli cells in hpg testes. Total Sertoli cell numbers were also significantly increased (1.5-fold) independently of FSH effects by T treatment alone. Selective FSH activity in αβ.6 hpg testes increased total spermatogonia numbers 3-fold, which established a normal spermatogonia/Sertoli cell ratio. FSH also elevated meiotic spermatocyte numbers 7-fold, notably at pachytene (28-fold), but induced only limited numbers of postmeiotic haploid cells (absent in hpg controls) that arrested during spermatid elongation. In contrast, T treatment alone had little effect on postnatal spermatogonial proliferation but greatly enhanced meiotic progression with total spermatocytes increased 12-fold (pachytene 53-fold) relative to hpg testes, and total spermatid numbers 11-fold higher than tg-FSH hpg testes. Combining tg-FSH and T treatment had no further effect on Sertoli or spermatogonia numbers relative to FSH alone but had marked additive and synergistic effects on meiotic cells, particularly pachytene (107-fold more than hpg), to establish normal meiotic germ cell/Sertoli cell ratios. Furthermore, tg-FSH had a striking synergistic effect with T treatment on total spermatid numbers (19-fold higher than FSH alone), although spermatid to Sertoli cell ratios were not fully restored to normal, indicating elevated Sertoli cell numbers alone are insufficient to establish a maximal postmeiotic germ cell capacity. This unique model has allowed a detailed dissection of FSH in vivo activity alone or with T and provided compelling evidence that FSH effects on spermatogenesis are primarily via Sertoli and spermatogonial proliferation and the stimulation of meiotic and postmeiotic germ cell development in synergy with and dependent on T actions.

EFFECT OF HYPOTHALAMIC LESIONS ON MATURATION AND ANNUAL CYCLICITY OF THE FERRET TESTIS

1974 ◽  
Vol 62 (1) ◽  
pp. 59-73 ◽  
Author(s):  
M. J. BAUM ◽  
D. A. GOLDFOOT
Keyword(s):  
Germ Cell ◽  
Lower Percentage ◽  
Seminiferous Tubules ◽  
Cell Type ◽  
Hypothalamic Lesions ◽  
Electrolytic Lesions ◽  
Testicular Size ◽  
Pachytene Spermatocytes ◽  
The Right

SUMMARY Sexually immature male ferrets received electrolytic lesions in the rostral mediobasal hypothalamus, and another group of males received sham operations. Testicular size, as estimated by weekly palpation, increased rapidly after the placement of lesions. Four weeks after the operation the right testis and epididymis were found to weigh significantly more in lesioned than in sham-operated animals, whereas body weight was the same in the two groups. The right testis of lesioned ferrets had a significantly higher Leydig cell index as well as significantly larger luminal and outer diameters of the seminiferous tubules. In addition, histological examination and classification of the seminiferous tubules showed that spermatogenesis was advanced in lesioned ferrets, with pachytene spermatocytes being the most advanced germ-cell type present in a significantly higher percentage of tubules, and spermatogonia being the most advanced germ-cell type present in a significantly lower percentage of tubules. Finally, at this time the concentration of testosterone per testis was significantly higher in lesioned than in sham-operated ferrets. When the remaining testis was biopsied 20 weeks after the operation it was found that spermatogenesis was still more advanced and the concentration of testosterone in blood was significantly higher in lesioned ferrets. By the time autopsy was performed 38 weeks after the operation, all parameters of testicular function in the sham-operated male ferrets had caught up with those of lesioned animals. In a second experiment it was found that hypothalamic lesions accelerated testicular growth without interfering with the subsequent occurrence of an annual regression and recrudescence of the testes.

scholarly journals Male germ cell transplantation in livestock

2006 ◽  
Vol 18 (2) ◽  
pp. 13 ◽  
Author(s):  
J. R. Hill ◽  
I. Dobrinski
Keyword(s):  
Stem Cells ◽  
Germ Cell ◽  
Cell Transplantation ◽  
Large Scale ◽  
Developmental State ◽  
Male Germ Cell ◽  
Seminiferous Tubules ◽  
Cell Transfer ◽  
Donor Sperm ◽  
Germ Cell Transplantation

Male germ cell transplantation is a powerful approach to study the control of spermatogenesis with the ultimate goal to enhance or suppress male fertility. In livestock animals, applications can be expanded to provide an alternative method of transgenesis and an alternative means of artificial insemination (AI). The transplantation technique uses testis stem cells, harvested from the donor animal. These donor stem cells are injected into seminiferous tubules, migrate from the lumen to relocate to the basement membrane and, amazingly, they can retain the capability to produce donor sperm in their new host. Adaptation of the mouse technique for livestock is progressing, with gradual gains in efficiency. Germ cell transfer in goats has produced offspring, but not yet in cattle and pigs. In goats and pigs, the applications of germ cell transplantation are mainly in facilitating transgenic animal production. In cattle, successful male germ cell transfer could create an alternative to AI in areas where it is impractical. Large-scale culture of testis stem cells would enhance the use of elite bulls by providing a renewable source of stem cells for transfer. Although still in a developmental state, germ cell transplantation is an emerging technology with the potential to create new opportunities in livestock production.

scholarly journals The Hypoxic Testicle: Physiology and Pathophysiology

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Juan G. Reyes ◽  
Jorge G. Farias ◽  
Sebastián Henríquez-Olavarrieta ◽  
Eva Madrid ◽  
Mario Parraga ◽  
...  
Keyword(s):  
Germ Cell ◽  
Testicular Torsion ◽  
Oxygen Supply ◽  
Cell Function ◽  
Cell Damage ◽  
The Body ◽  
Body Core Temperature ◽  
Seminiferous Tubules ◽  
Low Oxygen ◽  
Complex Biological Process

Mammalian spermatogenesis is a complex biological process occurring in the seminiferous tubules in the testis. This process represents a delicate balance between cell proliferation, differentiation, and apoptosis. In most mammals, the testicles are kept in the scrotum 2 to 7°C below body core temperature, and the spermatogenic process proceeds with a blood and oxygen supply that is fairly independent of changes in other vascular beds in the body. Despite this apparently well-controlled local environment, pathologies such as varicocele or testicular torsion and environmental exposure to low oxygen (hypoxia) can result in changes in blood flow, nutrients, and oxygen supply along with an increased local temperature that may induce adverse effects on Leydig cell function and spermatogenesis. These conditions may lead to male subfertility or infertility. Our literature analyses and our own results suggest that conditions such as germ cell apoptosis and DNA damage are common features in hypoxia and varicocele and testicular torsion. Furthermore, oxidative damage seems to be present in these conditions during the initiation stages of germ cell damage and apoptosis. Other mechanisms like membrane-bound metalloproteinases and phospholipase A2 activation could also be part of the pathophysiological consequences of testicular hypoxia.

Keratinocyte growth factor therapy in murine oleic acid-induced acute lung injury

2005 ◽  
Vol 288 (6) ◽  
pp. L1179-L1192 ◽  
Author(s):  
K. Ulrich ◽  
M. Stern ◽  
M. E. Goddard ◽  
J. Williams ◽  
J. Zhu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Acute Lung Injury ◽  
Gene Delivery ◽  
Lung Injury ◽  
Time Course ◽  
Lung Compliance ◽  
Alveolar Type ◽  
Protein Therapy ◽  
Cell Numbers ◽  
Atii Cell

Alveolar type II (ATII) cell proliferation and differentiation are important mechanisms in repair following injury to the alveolar epithelium. KGF is a potent ATII cell mitogen, which has been demonstrated to be protective in a number of animal models of lung injury. We have assessed the effect of recombinant human KGF (rhKGF) and liposome-mediated KGF gene delivery in vivo and evaluated the potential of KGF as a therapy for acute lung injury in mice. rhKGF was administered intratracheally in male BALB/c mice to assess dose response and time course of proliferation. SP-B immunohistochemistry demonstrated significant increases in ATII cell numbers at all rhKGF doses compared with control animals and peaked 2 days following administration of 10 mg/kg rhKGF. Protein therapy in general is very expensive, and gene therapy has been suggested as a cheaper alternative for many protein replacement therapies. We evaluated the effect of topical and systemic liposome-mediated KGF-gene delivery on ATII cell proliferation. SP-B immunohistochemistry showed only modest increases in ATII cell numbers following gene delivery, and these approaches were therefore not believed to be capable of reaching therapeutic levels. The effect of rhKGF was evaluated in a murine model of OA-induced lung injury. This model was found to be associated with significant alveolar damage leading to severe impairment of gas exchange and lung compliance. Pretreatment with rhKGF 2 days before intravenous OA challenge resulted in significant improvements in Po2, Pco2, and lung compliance. This study suggests the feasibility of KGF as a therapy for acute lung injury.

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