Physiological role for androgen binding protein-steroid complex in testis?
The concentration of unbound androgens in the lumen of rat testis seminiferous tubules is not dependent on the presence of the extra-cellular androgen binding protein (ABP); other parameters such as permeability properties, fluid dynamics and metabolic activities in different testicular compartments appear to have a much greater influence. It has been shown that in other target tissues the metabolic effects of steroids on cells depend on the concentration of the steroids which are not bound to extra-cellular proteins. It is therefore unlikely that the physiological function of ABP is related to the accumulation of androgens around germinal cells.
D000728:Androgens / Q000502:physiology*; D000818:Animals; D002352:Carrier Proteins / Q000502:physiology*; D005110:Extracellular Space / Q000502:physiology; D008297:Male; D011485:Protein Binding; D051381:Rats; D012671:Seminiferous Tubules / Q000502:physiology; D013094:Spermatozoa / Q000502:physiology; D013737:Testis / Q000502:physiology*; D013739:Testosterone / Q000378:metabolism
D000728:Androgens; D002352:Carrier Proteins; D013739:Testosterone