Correlation between blood‐testis barrier development and onset of the first spermatogenic wave in normal and in busulfan‐treated rats: A lanthanum and freeze‐fracture study

Abstract

Pregnant rats (day 13) received 10 mg/kg of Busulfan i.p. The seminiferous tubules of their offspring from post-natal age 1 day up to day 35 were examined with TEM after fixation plus intercellular tracers, and with freeze-fracture techniques. During this period, the inter-Sertoli tight junctions of controls increase both in number and in length. Between days 10 and 13 the seminiferous cords have numerous preleptotene and leptotene spermatocytes surrounded by tracer. The inter-Sertoli junctions are tortuous and predominantly perpendicular to the basal lamina. Between ages 13 and 20 days the seminiferous epithelium reaches zygotene-pachytene stages. The tracer is stopped at the inter-Sertoli junctions at this stage, whereas it still permeates tubules displaying preleptotene and leptotene spermatocytes. Freeze-fracture shows that the orientation of inter-Sertoli junctions has changed to parallel, both to each other and to the basal lamina. In the Busulfan-treated rats, the tubules continue having, up to post-natal day 30, only Sertoli cells and scanty spermatogonia. In these, lanthanum penetration goes as far as the apical Sertoli cell region; the inter-Sertoli junctions still show tortuous strands, and most are oriented perpendicular to the basal lamina. This indicates that formation of the first competent inter-Sertoli junctions is temporo-spatially simultaneous with the appearance of zygotene-pachytene spermatocytes.

Selective Ablation of the Androgen Receptor in Mouse Sertoli Cells Affects Sertoli Cell Maturation, Barrier Formation and Cytoskeletal Development

“…Moreover, intense immunostaining for these proteins was located further from the periphery of the tubule and perpendicular to the basal lamina rather than parallel to it in SCARKO mice on and after day 35. A similar formation of lanthanum-impermeable junctions perpendicular to the basal lamina has been described in rats after prenatal treatment with busulphan [47].…”

Regulation of testicular tight junctions by gonadotrophins in the adult Djungarian hamster in vivo

“…The BTB allows for the establishment of a specialised epithelial microenvironment, separated from factors found in the interstitium, which is conducive to meiotic and post-meiotic GC development. In the absence of a functional BTB, spermatogenesis continues only as far as spermatocytes in rodents (Cavicchia & Sacerdote 1991, Gow et al 1999, Morales et al 2007, highlighting the indispensability of the BTB. While intensively studied (for reviews see (Lui et al 2003, Turner 2006, Matter & Balda 2007) the regulation of TJ proteins in the testis is poorly understood.…”

Distribution of Sertoli cell microtubules, microtubule‐dependent motors, and the Golgi apparatus before and after tight junction formation in developing rat testis

“…Morphology. By 20 days, a time when the bloodtestis barrier is known to be functional (Cavicchia and Sacerdote, 1991;Gilula et al, 1976;Russell et al, 1989;Vitale et al, 19731, pachytene germ cells were present (Fig. 4A).…”

“…The time period of this study was designed to span Sertoli-Sertoli cell tight junction formation in the rat seminiferous epithelium. Ultrastructural morphology and parallel bands of intramembranous particles on freeze fracture images indicate that Sertoli-Sertoli cell tight junctions develop between 15 and 19 days of age (Cavicchia and Sacerdote, 1991;Gilula et al, 1976;Meyer et al, 1977;Nicander, 1967). Formation of the seminiferous tubule lumen, which depends on tight junction integrity, varies between tubules but is rare before 10 days, occurring in 85% of tubules by 18 days (Russell, 1989).…”

“…Formation of the seminiferous tubule lumen, which depends on tight junction integrity, varies between tubules but is rare before 10 days, occurring in 85% of tubules by 18 days (Russell, 1989). The first evidence of a functional tight junction (the blood-testis barrier) has been demonstrated by the exclusion of lanthanum beginning at 19 days (Cavicchia and Sacerdote, 1991;Vitale et al, 1973) or by the rapid increase in tubule fluid production at 20 days (Jegou et al, 1982;Russell et al, 1989). Here, the actin staining pattern in Sertoli cells progressed from one of pale cortical staining at 5 days of age to an intense accumulation at Sertoli-Sertoli cell Fig.…”