Isolated seminiferous tubules of rat testis contain considerable urokinase-inhibiting activity. An immunohistological analysis revealed the presence of plasminogen activator inhibitor type 1 (PAI-1) in the basement membrane as well as in the interior of the tubules. Distribution and intensity of the intratubular immunoreactivity depends on the stage of the seminiferous cycle. A relatively weak signal is present around elongated nuclei of spermatids at the beginning of chromatin condensation. The signal intensity increases in the course of differentiation until a maximum is reached at stages VII-VIII. In these stages PAI-1 immunoreactivity is localised around the nuclei of the late spermatids as well as along their tails. Spermatozoa in the ductus epididymis also strongly react with the PAI-1-specific antiserum, suggesting that the inhibitor remains associated with the germ cells after spermiation and during maturation in the epididymis. In intact mature spermatozoa isolated from epididymis cauda by 'swimming-up' in non-capacitation medium, PAI-1 antigen is localised on the plasma membrane surrounding the head. In addition, in fixed and permeabilised cells the immunoreactivity is detectable in the acrosome and in the tail. Possible functions of PAI-1 in spermatogenesis, sperm motility and sperm-egg interaction are discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.