Biomaterial Database

Absorptive and secretory functions of the perfused rat cauda epididymidis. 1978

P Y Wong, and C H Yeung

1. A microperfusion technique has been developed to study transport processes in the rat cauda epididymidis in vivo. 2. Na+ and water were found to be reabsorbed by the perfused rat cauda epididymidis at the rates of 3.000 +/- 0.25 n-equiv cm-1 min-1 (mean +/- S.E., n = 14) and 20.7 +/- 1.7 nl. cm-1 min-1 (mean +/- S.E., n = 14) respectively. Reabsorption of Na+ was isotonic. 3. K+ was found to be secreted into the ductal lumen at the rate of 0.124 +/- 0.016 n-equiv cm-1 min-1 (mean +/- S.E., n = 14). 4. Na+ reabsorption and water reabsorption were abolished by removing Na+ ions from the perfusion medium. The dependence of rate of net Na+ reabsorption on the intraluminal Na+ ion concentration showed saturation kinetics, with the apparent Km values of about 20 mM Na+. The dependence of water reabsorption on the intraluminal Na+ ion concentration also followed closely that of Na+. 5. Application of amiloride 10(-4) M) to the perfusion fluid abolished both Na+ and water reabsorption by the rat cauda epididymidis. 6. Removal of chloride from the perfusion fluid had no effect on Na+ and water reabsorption but increased the K+ secretion rate by threefold. 7. Proteins were also found to be secreted by the rat cauda epididymidis at a rate of 11.7 +/- 1.8 ng cm-1 min-1 (mean +/- S.E., n = 11). The secretory rate was not dependent on the intraluminal Na+ ion concentration. 8. Castration in rats abolished the reabsorption of Na+ and water and secretion of K+ and proteins by the rate cauda epididymidis. These effects could be reversed by injecting testosterone propionate into castrated rats. 9. The possible role of these transport processes in sperm maturation is discussed.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D002369	Castration	Surgical removal or artificial destruction of gonads.	Gonadectomy,Castrations,Gonadectomies
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.
D000584	Amiloride	A pyrazine compound inhibiting SODIUM reabsorption through SODIUM CHANNELS in renal EPITHELIAL CELLS. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride is used in conjunction with DIURETICS to spare POTASSIUM loss. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p705)	Amidal,Amiduret Trom,Amiloberag,Amiloride Hydrochloride,Amiloride Hydrochloride, Anhydrous,Kaluril,Midamor,Midoride,Modamide,Anhydrous Amiloride Hydrochloride,Hydrochloride, Amiloride,Hydrochloride, Anhydrous Amiloride,Trom, Amiduret
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
D001693	Biological Transport, Active	The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.	Active Transport,Uphill Transport,Active Biological Transport,Biologic Transport, Active,Transport, Active Biological,Active Biologic Transport,Transport, Active,Transport, Active Biologic,Transport, Uphill
D012636	Secretory Rate	The amount of a substance secreted by cells or by a specific organ or organism over a given period of time; usually applies to those substances which are formed by glandular tissues and are released by them into biological fluids, e.g., secretory rate of corticosteroids by the adrenal cortex, secretory rate of gastric acid by the gastric mucosa.	Rate, Secretory,Rates, Secretory,Secretory Rates
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23