scholarly journals PERMEABILITY OF SERTOLI CELL TIGHT JUNCTIONS TO LANTHANUM AFTER LIGATION OF DUCTUS DEFERENS AND DUCTULI EFFERENTES

1973 ◽  
Vol 59 (3) ◽  
pp. 559-572 ◽  
Author(s):  
William B. Neaves

The permeability of Sertoli cell tight junctions to lanthanum administered during fixation has been compared in rats after ligation of the ductus deferens and after ligation of the ductuli efferentes. In both control and vasoligated testes, lanthanum penetrated only short distances into the Sertoli cell tight junctions before stopping abruptly. The tight junction, consisting of numerous pentalaminar fusions of contiguous Sertoli cell membranes, prevented diffusion of lanthanum into the adluminal compartment of the seminiferous epithelium. In rats with ligated ductuli efferentes, lanthanum completely permeated many Sertoli cell tight junctions and occupied intercellular spaces of the adluminal compartment. In spite of their newly acquired permeability to lanthanum, tight junctions retained characteristic ultrastructural features, including numerous membrane fusions. When lanthanum-filled tight junctions were sectioned en face, membrane fusions appeared as pale lines in lakes of electron-opaque tracer. These linearly extensive fasciae occludentes occasionally ended blindly, suggesting that lanthanum may have traversed the junction by diffusing around such incomplete barriers. The increased permeability of Sertoli cell tight junctions after efferent ductule ligation, which caused rapid testicular weight gain followed by atrophy, indicates that tight junctions are sensitive to enforced retention of testicular secretions inside the seminiferous tubules. The apparent normalcy of Sertoli cell tight junctions after vasoligation, which had no effect on testis weight, supports the view that blockage of testicular secretions distal to the epididymis is relatively innocuous.

Author(s):  
Rabah Mamou ◽  
Elara Moudilou ◽  
Jean-Marie Exbrayat ◽  
Mansour Amroun

The reproductive cycle of male wall lizard Podarcis vaucheri (Boulenger, 1905) living in Djurdjura mountain, was analyzed from April till October 2014. Its seasonal mixed-type cycle was characterized by three phases: sexual activity, quiescence and recrudescence. After the emergence of lizard from hibernation an intense sexual activity was observed in spring (April, May, and June) at which the testicular weight and seminiferous tubules diameter reached their maximal values. At this period, spermiogenesis was also maximal and the spermiation allowed the release of a large quantity of spermatozoa in both the seminiferous tubules and epididymis lumen. In July, a short sexual resting period followed, during which the testes mass and seminiferous tubules diameter decreased. Spermatogonia and some primary spermatocytes were observed against the wall of seminiferous tubules. The recrudescence period (August, September and October) was characterized by a progressive increase of the testis weight and seminiferous tubules diameter. Spermatocytogenesis began in August, and spermiogenesis occurred in September and October, before the diapause period. But the presence of spermatozoids was not signaled in the epididymis lumen. Field observations and microscopic evidence of testis showed that both sexes reproduced synchronously during spring and early summer.


2016 ◽  
Vol 33 (1) ◽  
pp. 36-45 ◽  
Author(s):  
Jijing Tian ◽  
Ye Ding ◽  
Ruiping She ◽  
Longhuan Ma ◽  
Fang Du ◽  
...  

The health effects of bisphenol A (BPA) have become a great concern in recent years. In this study, the reproductive toxicity of BPA was investigated. Male CD-1 mice were orally administrated with BPA (0, 100, 300 and 600 mg kg−1 body weight) for 56 consecutive days. Results showed that relative testis weight to total body weight was significantly lower in the high-dose group ( p < 0.01, p < 0.05). Microscopic examination under light and transmission electron microscopes showed disorders of spermatogenesis after BPA exposure, including rough basal lamina of seminiferous tubules and damage of tight junctions between Sertoli cells. Further study by terminal-deoxynucleoitidyl transferase–mediated nick end labelling assay showed a significant induction of apoptosis in the testis tissue of the BPA groups ( p < 0.01). Immunohistochemical study found that the expression of androgen-binding protein (ABP) was significantly decreased in BPA-treated mice ( p < 0.01). Our results indicated that impairment of the basal lamina of seminiferous tubules and tight junctions may contribute to BPA-induced cell injury. A decrease in the level of ABP could be the possible mechanism for the reproductive toxicity of BPA. These findings provided direct evidence and novel insight into the reproductive toxicity of BPA and may have implications for understanding the toxicity of other endocrine disruptors.


1993 ◽  
Vol 5 (1) ◽  
pp. 83 ◽  
Author(s):  
C Monet-Kuntz ◽  
I Fontaine

The response of lamb Sertoli cells to follicle stimulating hormone (FSH) was investigated by measuring transferrin secretion in seminiferous tubule cell cultures throughout the non-pubertal and the prepubertal periods. Cells could be cultured from birth until they attained a testicular weight of 19 g. The characteristics of individual dose-response curves were compared according to the breed, season of birth and testicular weight of the lambs. At the same season of birth and within a given testis weight range, dose-response curves of Romanov and Ile-de-France lambs were similar. Within a given testis weight range, spring-born animals exhibited a higher maximal transferrin secretion than autumn-born lambs, but the ED50 was similar. The main factor of variation of the dose-response curve parameters was the testicular weight of the lambs: the amplitude of FSH response increased 3-fold from a testicular weight of 6 g onwards, i.e. from the appearance of spermatogonia in seminiferous tubules. The ED50 increased 5-fold from 11 g onwards, i.e. from the beginning of the prepubertal period. Thus, Sertoli cells become less sensitive to FSH as spermatogenesis develops in seminiferous tubules. This phenomenon is largely the result of higher phosphodiesterase activity and is greatly reduced by 1-methyl-3-isobutyl-xanthine (MIX).


1988 ◽  
Vol 119 (2) ◽  
pp. 315-326 ◽  
Author(s):  
R. M. Sharpe ◽  
I. A. Swanston ◽  
I. Cooper ◽  
C. G. Tsonis ◽  
A. S. McNeilly

ABSTRACT Immunoreactive inhibin was measured in testicular interstitial fluid (IF) from rats during sexual maturation or after impairment of spermatogenesis induced by ethane dimethanesulphonate (EDS), unilateral cryptorchidism or local heating (43 °C, 30 min) of the testes, to ascertain its usefulness as a marker of changing Sertoli cell function. Cultures of isolated seminiferous tubules were also studied. Inhibin was measured by a radioimmunoassay directed towards the first 26 amino acids of the N-terminus of the α-subunit, and the results confirmed for selected pools of IF by in-vitro bioassay using dispersed ovine pituitary cells. During puberty, IF levels of immunoactive inhibin fell by more than 90% (P<0·001) between 30 and 60 days of age, a decrease paralleled by the levels of androgen-binding protein (ABP), another Sertoli cell product secreted into IF. These changes also paralleled, but preceded, the fall (60%; P<0·001) in serum levels of FSH between 40 and 70 days, while the serum and IF levels of testosterone increased more than two-fold over this period. When adult rats were injected with EDS to destroy the Leydig cells, testosterone levels in IF and serum were undetectable at 3 and 7 days after treatment, were just detectable at 14 days and thereafter returned slowly towards normal by 42 days. The initial androgen withdrawal following EDS treatment caused a progressive reduction in testicular weight up to 21 days and this was accompanied by a significant increase in the serum levels of FSH and a two- to threefold increase in the IF levels of immunoactive inhibin (and also of ABP). Serum FSH and IF levels of immunoactive inhibin returned to within the normal range by 42 days when testosterone levels had normalized. In contrast, in two other experimental situations in which a marked decrease in testicular weight coupled with an increase in IF levels of ABP occurs, different results for the IF levels of immunoactive inhibin were obtained. Thus, in rats exposed to local heating of the testes, IF levels of immunoactive inhibin remained unchanged from control values at 21–40 days after treatment, a finding confirmed by bioassay results. In rats made unilaterally cryptorchid for 10 months, levels of immunoactive inhibin in IF were reduced by 60% (P<0·01) in the abdominal compared with the contralateral scrotal testis. These results suggest that (1) IF levels of immunoactive inhibin do not always change in parallel to the levels of ABP and may be a useful marker of changing Sertoli cell function, and (2) in at least two situations (puberty and after EDS treatment), there may be a positive relationship between the serum levels of FSH and the IF levels of immunoactive inhibin. This positive relationship was confirmed by in-vitro findings in which FSH and dibutyryl cyclic AMP (but not testosterone) were shown to stimulate immunoactive inhibin production by isolated rat seminiferous tubules during culture for 2–6 days. J. Endocr. (1988) 119, 315–326


Author(s):  
William J. Kovacs

The testes are the source of both germ cells and hormones essential for male reproductive function. The production of both sperm and steroid hormones is under complex feedback control by the hypothalamic-pituitary system. The testis consists of a network of tubules for the production and transport of sperm to the excretory ducts and a system of interstitial cells (called Leydig cells) that express the enzymes required for the synthesis of androgens. The spermatogenic or seminiferous tubules are lined by a columnar epithelium composed of the germ cells themselves as well as supporting Sertoli cells surrounded by peritubular tissue made up of collagen, elastic fibers, and myofibrillar cells. Tight junctions between Sertoli cells at a site between the spermatogonia and the primary spermatocyte form a diffusion barrier that divides the testis into two functional compartments, basal and adluminal. The basal compartment consists of the Leydig cells surrounding the tubule, the peritubular tissue, and the outer layer of the tubule containing the spermatogonia. The adluminal compartment consists of the inner two-thirds of the tubules containing primary spermatocytes and germ cells in more advanced stages of development. The base of the Sertoli cell is adjacent to the basement membrane of the spermatogenic tubule, with the inner portion of the cell engulfing the developing germ cells so that spermatogenesis actually takes place within a network of Sertoli cell cytoplasm. The mechanism by which spermatogonia pass through the tight junctions between Sertoli cells to begin spermatogenesis is unknown. The close proximity of the Leydig cell to the Sertoli cell with its embedded germ cells is thought to be critical for normal male reproductive function. The seminiferous tubules empty into a network of ducts termed the rete testis. Sperm are then transported into a single duct, the epididymis. Anatomically, the epididymis can be divided into the caput, the corpus, and the cauda regions. The caput epididymidis consists of 8 to 12 ductuli efferentes, which have a larger lumen tapering to a narrower diameter at the junction of the ductus epididymidis.


Author(s):  
Rita Meyer ◽  
Zoltan Posalaky ◽  
Dennis Mcginley

The Sertoli cell tight junctional complexes have been shown to be the most important structural counterpart of the physiological blood-testis barrier. In freeze etch replicas they consist of extensive rows of intramembranous particles which are not only oriented parallel to one another, but to the myoid layer as well. Thus the occluding complex has both an internal and an overall orientation. However, this overall orientation to the myoid layer does not seem to be necessary to its barrier function. The 20 day old rat has extensive parallel tight junctions which are not oriented with respect to the myoid layer, and yet they are inpenetrable by lanthanum. The mechanism(s) for the control of Sertoli cell junction development and orientation has not been established, although such factors as the presence or absence of germ cells, and/or hormones, especially FSH have been implicated.


Reproduction ◽  
2000 ◽  
pp. 443-452 ◽  
Author(s):  
MA Peters ◽  
DG de Rooij ◽  
KJ Teerds ◽  
I van Der Gaag ◽  
FJ van Sluijs

Spermatogenesis was examined in testes from 74 dogs of various breeds without clinically detected testicular disease. A modified Johnsen score system was used to determine whether spermatogenesis deteriorates with ageing. The diameter of seminiferous tubules was measured in dogs without testicular disease to examine other possible effects of ageing on tubular performance. There appeared to be no relation between age and these variables. The influence of testicular tumours on spermatogenesis was also investigated in both affected and unaffected testes. The testes of 28 dogs with clinically palpable tumours and 21 dogs with clinically non-palpable tumours were investigated. In cases of unilateral occurrence of a tumour, impairment of spermatogenesis was observed only in the affected testis of dogs with clinically detected tumours. Bilateral occurrence of tumours, whether detected clinically or non-clinically, was associated with severe impairment of spermatogenesis. The prevalence of tumours increased during ageing. Eighty-six per cent of the clinically detected and 57% of the non-clinically detected tumours were found in old dogs. Multiple types of tumour and bilateral occurrence were very common. Seminomas and Leydig cell tumours were more frequent than Sertoli cell tumours. It was concluded that spermatogenesis per se did not decrease during ageing in dogs but the occurrence of testicular tumours increased with ageing and affected spermatogenesis significantly, as reflected by a lower Johnsen score.


2018 ◽  
Vol 47 (2) ◽  
pp. 722-729 ◽  
Author(s):  
Yang Yu ◽  
Qi Xi ◽  
Ruixue Wang ◽  
Hongguo Zhang ◽  
Leilei Li ◽  
...  

Objective This study aimed to assess the value of measuring the tubule diameter during microdissection testicular sperm extraction (micro-TESE) in predicting outcomes in patients with Sertoli cell-only syndrome (SCOS). Methods Fifty-six consecutive patients with SCOS were included. Patients were classified into two groups on the basis of the diameter of seminiferous tubules measured against 5/0 surgical suture (≥100 µm or <100 µm). Results The sperm retrieval rate (SRR) in men with a tubule diameter ≥100 µm was significantly lower than that in those with <100 µm (3.1% vs. 25.0%). The SRR from the contralateral testis in men with a tubule diameter ≥100 µm was lower than that in those with <100 µm (0% vs. 14.3%). Men with a tubule diameter ≥100 µm had a significantly larger testis and lower follicle-stimulating hormone levels than did men with <100 µm (8.1 ± 2.4 vs. 5.3±1.8 mL, 19.9 ± 9.7 vs. 25.9 ± 7.1 mIU/mL, respectively). Conclusions The diameter of tubules is a useful predictor for a successful SRR in men with SCOS. Intraoperative assessment of homogeneous large tubules allows some men to perform a limited (superficial) contralateral micro-TESE after no spermatozoa are initially identified.


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