title: [Studies on the endocrine and spermatogenetic testicular function 6. In-vitro biosynthesis of testosterone in fractions of the smooth endoplasmic reticulum from the rat's testis in relationship to age and quality of dietary proteins].
abstract: The metabolic activity of testosterone biosynthesis in fractions of the unstriated endoplasmatic reticulum of testicular tissue in animals in puberty living on corn gluten was about 20 per cent below that in animals that were fed corn gluten plus supplemented amino acids. Such lowered metabolic activity was recordable even from adult animals for another 30 days despite change of feed to high-quality proteins. The conversion rate of progesterone in testostrone still was lowered by some ten per cent. If change of enzyme activity in testosterone biosynthesis was caused by feeding different protein qualities, such variation could not be normalised within short time. Testosterone biosynthesis during postnatal development of rat was of two-phase nature even in the presence of temporary deficit due to low-quality feed protein. A regulation mechanism is assumed to exist and to enable completion of sexual maturity even on the basis of low-quality feed proteins. The metabolic activity at the time of qualitative transformation of the A/T ratio was significantly reduced, and this resulted in delayed occurrence of spermatogenesis as well as in retardation of body and testicular weight development.
mesh_terms: D000821:Animal Feed; D000818:Animals; D004044:Dietary Proteins / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D009130:Muscle, Smooth / Q000378:metabolism; D051381:Rats; D012741:Sexual Maturation; D013091:Spermatogenesis; D013737:Testis / Q000378:metabolism / Q000502:physiology*; D013739:Testosterone / Q000096:biosynthesis*
chemical_list: D004044:Dietary Proteins; D013739:Testosterone
vernacular_title: Untersuchungen zur endokrinen und spermiogenen Hodenfunktion 6. Mitteilung: Zur in vitro-Biosynthese des Testosterons in Fraktionen des glatten endoplasmatischen Retikulums aus Rattenhoden in Abhängigkeit von Alter und Nahrungsproteinqualität