Biomaterial Database

Protein synthesis and secretion by the rat caput epididymidis in vivo: influence of the luminal microenvironment. 1995

T T Turner, and D W Miller, and E A Avery

Department of Urology, University of Virginia School of Medicine, Charlottesville 22908, USA.

The role of intraluminal factors in regulating the functions of the epididymal epithelium is unknown and virtually unexplored. Simultaneous in vivo microperfusion and microperfusion procedures were carried out on rat caput epididymal tubules to examine the effects of the intraluminal microenvironment on protein synthesis and secretion. Caput tubules were perifused with 35S-methionine for 3 h while the tubule lumen was subjected to a stop-flow perfusion of either native caput content from another epididymis (NCC), artificial caput fluid containing no testicular factors (ACF), or rete testis fluid (RTF). Protein synthesis and secretion were measured quantitatively as trichloroacetic acid- (TCA) precipitable 35S-methionine-labeled proteins (cpm/microliter) and qualitatively as autoradiograms of electrophoresed 35S-methionine-labeled proteins. Electrophoresed proteins, i.e., those in fluids collected by micropuncture, were: perifused interstitial fluid (IF), lumen fluid from the perifused but not perfused length of tubule (LF), and the perfusion fluid (PF) re-collected from the tubule lumen. Undiluted tubule extract (TE) of the perfused length of tubule was also analyzed. ACF in the lumen caused a significant reduction in proteins synthesized and secreted by the epithelium, and RTF in the lumen returned protein synthesis and secretion to control values. For example, TCA-precipitable 35S-methionine-labeled proteins in TE of tubules perfused with NCC, ACF, or RTF were 107.6 +/- 13.1, 58.9 +/- 6.9, and 121.9 +/- 19.7 x 10(3) cpm/microliters, respectively. Autoradiograms reinforced this data. Subsequently, tubules were perfused with ACF or ACF containing physiological concentrations of sex hormone-binding globulin (SHBG; an androgen-binding protein [ABP] homolog), 5 alpha-dihydrotestosterone (DHT), or SHBG+DHT.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008715	Methionine	A sulfur-containing essential L-amino acid that is important in many body functions.	L-Methionine,Liquimeth,Methionine, L-Isomer,Pedameth,L-Isomer Methionine,Methionine, L Isomer
D010477	Perfusion	Treatment process involving the injection of fluid into an organ or tissue.	Perfusions
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
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.
D004848	Epithelium	The layers of EPITHELIAL CELLS which cover the inner and outer surfaces of the cutaneous, mucus, and serous tissues and glands of the body.	Mesothelium,Epithelial Tissue,Mesothelial Tissue,Epithelial Tissues,Mesothelial Tissues,Tissue, Epithelial,Tissue, Mesothelial,Tissues, Epithelial,Tissues, Mesothelial
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012738	Sex Hormone-Binding Globulin	A glycoprotein migrating as a beta-globulin. Its molecular weight, 52,000 or 95,000-115,000, indicates that it exists as a dimer. The protein binds testosterone, dihydrotestosterone, and estradiol in the plasma. Sex hormone-binding protein has the same amino acid sequence as ANDROGEN-BINDING PROTEIN. They differ by their sites of synthesis and post-translational oligosaccharide modifications.	Sex Steroid-Binding Protein,Testosterone-Estradiol Binding Globulin,Binding Globulin, Testosterone-Estradiol,Globulin, Sex Hormone-Binding,Globulin, Testosterone-Estradiol Binding,Hormone-Binding Globulin, Sex,Sex Hormone Binding Globulin,Sex Steroid Binding Protein,Steroid-Binding Protein, Sex,Testosterone Estradiol Binding Globulin
D013196	Dihydrotestosterone	A potent androgenic metabolite of TESTOSTERONE. It is produced by the action of the enzyme 3-OXO-5-ALPHA-STEROID 4-DEHYDROGENASE.	5 alpha-Dihydrotestosterone,Androstanolone,Stanolone,17 beta-Hydroxy-5 beta-Androstan-3-One,17beta-Hydroxy-5alpha-Androstan-3-One,5 beta-Dihydrotestosterone,5-alpha Dihydrotestosterone,5-alpha-DHT,Anaprotin,Andractim,Dihydroepitestosterone,Gelovit,17 beta Hydroxy 5 beta Androstan 3 One,17beta Hydroxy 5alpha Androstan 3 One,5 alpha DHT,5 alpha Dihydrotestosterone,5 beta Dihydrotestosterone,Dihydrotestosterone, 5-alpha,beta-Hydroxy-5 beta-Androstan-3-One, 17
D013737	Testis	The male gonad containing two functional parts: the SEMINIFEROUS TUBULES for the production and transport of male germ cells (SPERMATOGENESIS) and the interstitial compartment containing LEYDIG CELLS that produce ANDROGENS.	Testicles,Testes,Testicle