Immunocytochemical Localization of Androgen-Binding Protein in the Male Rat Reproductive Tract*

Abstract

The localization of androgen-binding protein (ABP) in the reproductive tract of young adult male rats was studied with the peroxidase-antiperoxidase technique using frozen sections and light microscopy. Within the seminiferous tubules, a positive reaction was noted in the apical portion of the epithelium, apparently in spermatids and/or Sertoli cells. ABP was localized in granules in the apical cytoplasm of the principal epithelial cells of the proximal part of the caput epididymis and in the epithelial cells of the ductuli efferentes. The cells in the distal part of the caput as well as the corpus and cauda of the epididymis did not contain ABP. Numerous coated vesicles and multivesicular bodies were present in the supranuclear cytoplasm of the epididymal epithelium where ABP was taken up. The results indicate that ABP is taken up from the lumen by epithelial cells of the ductuli efferentes and proximal part of the caput epididymis.

Use of monoclonal antibody techniques to study the ontogeny of bovine anti-Mullerian hormone

“…Establishment of the blood-testis barrier in the rat is followed by a fall in serum concentration of androgen-binding protein (Gunsalus, Musto & Bardin, 1978 Fig. 1), but such cells are heavily stained by an immunocytochemical reaction carried out with an antibody specifically directed against androgen-binding protein (Pelliniemi et al, 1981;Attramadal, Bardin, Gunsalus, Musto & Hansson, 1981).…”

Estrogen receptors and function in the male reproductive system

“…This process occurs by absorption or receptor-mediated endocytosis, the main mechanism involved in the capture of large molecules from the testicular fluid (46). The androgen binding protein (ABP) and the sulphated glycoprotein 2 (SGP-2) are examples of proteins absorbed by the efferent ducts epithelium (47,48). Some of the proteins secreted by the epithelial cells of the efferent ductules have already been identified, such as the saposin 1 (SGP-1) and the pro-enkephalins (49).…”

Androgen Transport Proteins: Physical Properties, Hormonal Regulation, and Possible Mechanism of TeBG and ABP Action

“…The results of a stereochemical analysis of steroid binding preferences to ABP and CR support this model [38]. Biological support for ABP uptake in the epididymis comes from the following facts: (1) epididymal ABP concentration declines from the caput to cauda [26]; (2) the initial segment of the caput requires androgen and a testicular substance, possibly ABP, to maintain normal morphology 1171; and (3) ABP has been shown to be internalized by specific caput epididymal cells [54]. These cells were in the same region of the epididymis that could not be maintained by androgen alone [17].…”