Refereed journal article or data article (A1)
Testicular plasminogen activators during postnatal development in the rat
List of Authors: Vihko KK, Toppari J, Saksela O, Suominen JJ, Parvinen M
Publication year: 1986
Journal: Acta endocrinologica
Journal name in source: Acta endocrinologica
Journal acronym: Acta Endocrinol (Copenh)
Volume number: 112
Issue number: 3
Start page: 431
End page: 5
Number of pages: 5
ISSN: 0001-5598
DOI: http://dx.doi.org/10.1530/acta.0.1120431
Abstract
In the seminiferous epithelium, Sertoli cells secrete plasminogen activator (PA) under regulation of follicle stimulating hormone, cyclic AMP and neighbouring spermatogenic cells. Recent observations suggest that preleptotene spermatocytes upon their release from the basement membrane of the seminiferous tubule are important regulators of PA secretion. To study further the role of PA's in the seminiferous tubules, we have analyzed the endogenous levels and secretion rates of PA at various ages during postnatal development, and performed biochemical analyses of the types of PA in the testis and spent media from seminiferous tubular cultures. Cyclic secretion of PA started at the age of 28 days, and from 40 days onwards, the high secretion rates were localized in stages VII and VIII of the cycle of the seminiferous epithelium. The secreted PA is most obviously of the urokinase type; both urokinase-type and tissue-type PA-like activities were found in seminiferous tubular homogenates. The increase in testicular PA levels concomitant to the onset of meiosis in the epithelium was due to the urokinase-type PA-like activity.
In the seminiferous epithelium, Sertoli cells secrete plasminogen activator (PA) under regulation of follicle stimulating hormone, cyclic AMP and neighbouring spermatogenic cells. Recent observations suggest that preleptotene spermatocytes upon their release from the basement membrane of the seminiferous tubule are important regulators of PA secretion. To study further the role of PA's in the seminiferous tubules, we have analyzed the endogenous levels and secretion rates of PA at various ages during postnatal development, and performed biochemical analyses of the types of PA in the testis and spent media from seminiferous tubular cultures. Cyclic secretion of PA started at the age of 28 days, and from 40 days onwards, the high secretion rates were localized in stages VII and VIII of the cycle of the seminiferous epithelium. The secreted PA is most obviously of the urokinase type; both urokinase-type and tissue-type PA-like activities were found in seminiferous tubular homogenates. The increase in testicular PA levels concomitant to the onset of meiosis in the epithelium was due to the urokinase-type PA-like activity.