Biomaterial Database

The effect of castration and testosterone replacement on specific proteins and androgen levels of the rat epididymis. 1975

E J Podestá, and R S Calandra, and M A Rivarola, and J A Blaquier

The normal weight increase of the epididymis during sexual maturation and its maintenance through adulthood were found to be dependent on the provision of androgens. Binding of [3H]dihydrotestosterone (DHT) to the epididymal 8S cytoplasmic receptor gradually decreased after castration to become undetectable after 25 days. Binding to the androgen binding protein (ABP) was absent 4 days after castration and was not reinduced by 3 weeks of testosterone (T) administration. Unilateral castration for periods of up to 27 days showed the disappearance of ABP with preservation of the 8S receptor on the castrated side, indicating a testicular source for ABP and the epididymal origin of the 8S receptor. The tissue concentrations of T and DHT in the epididymis became undetectable 30 days after castration and were restored to normal values by administration of testosterone in large doses (1.5 mg/100 g BW). Similar results were obtained in rats castrated at 10 days of age and injected with testosterone until 60 days old. The ratio DHT/T was depressed in the castrate and increased with testosterone treatment. The protein content of the epididymis (mg of protein/g wet weight) was also found to be influenced by androgens. Our results show evidence of some mechanisms involved in the trophic effect of androgens upon the epididymis and suggest the possible androgenic control of epididymal 5alpha-reductase activity. They also indicate that a testicular factor is required for the maintenance of the 8S cytoplasmic androgen receptor. It is not known whether this factor is testosterone or some other testicular secretion.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D009929	Organ Size	The measurement of an organ in volume, mass, or heaviness.	Organ Volume,Organ Weight,Size, Organ,Weight, Organ
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D011506	Proteins	Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.	Gene Products, Protein,Gene Proteins,Protein,Protein Gene Products,Proteins, Gene
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D002369	Castration	Surgical removal or artificial destruction of gonads.	Gonadectomy,Castrations,Gonadectomies
D003593	Cytoplasm	The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)	Protoplasm,Cytoplasms,Protoplasms
D003600	Cytosol	Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.	Cytosols
D004822	Epididymis	The convoluted cordlike structure attached to the posterior of the TESTIS. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of SPERMATOZOA.