Biomaterial Database

Calcium transport across segments of the rabbit distal nephron in vitro. 1978

G R Shareghi, and L C Stoner

The mechanism of Ca2+ transport by various segments of the distal nephron was studied in vitro using the isolated perfused tubule technique. Calcium absorption in the distal convoluted tubule (DCT) and the granular portion of the cortical collecting duct (CCTg) was significantly enhanced in the presence of parathyroid hormone (PTH), 3 X 10(-2) U/ml. Na+ was absorbed from and K+ was secreted into the lumen of the DCT. The presence of amiloride (5 X 10(-5) M) or furosemide (5 X 10(-5) M) in the perfusate of DCT each caused a partial inhibition of Na+ but not Ca2+ absorption. The foregoing result with Na+ is consistent with the heterogeneous nature of DCT. Net Na+ absorption and K+ secretion also occurred in the CCTg; both processes were completely inhibited by amiloride. Ca2+ absorption occurred in the thick ascending limb of Henle's loop; it was not enhanced by PTH, and the results were consistent with passive movement. No net Ca2+ movement was observed in the nongranular (light) segment of the cortical collecting tubule in the presence or absence of PTH or dibutyryl cyclic adenosine monophosphate.

UI	MeSH Term	Description	Entries
D007684	Kidney Tubules	Long convoluted tubules in the nephrons. They collect filtrate from blood passing through the KIDNEY GLOMERULUS and process this filtrate into URINE. Each renal tubule consists of a BOWMAN CAPSULE; PROXIMAL KIDNEY TUBULE; LOOP OF HENLE; DISTAL KIDNEY TUBULE; and KIDNEY COLLECTING DUCT leading to the central cavity of the kidney (KIDNEY PELVIS) that connects to the URETER.	Kidney Tubule,Tubule, Kidney,Tubules, Kidney
D007685	Kidney Tubules, Collecting	Straight tubes commencing in the radiate part of the kidney cortex where they receive the curved ends of the distal convoluted tubules. In the medulla the collecting tubules of each pyramid converge to join a central tube (duct of Bellini) which opens on the summit of the papilla.	Kidney Collecting Ducts,Kidney Collecting Duct,Collecting Duct, Kidney,Collecting Ducts, Kidney
D007686	Kidney Tubules, Distal	The portion of renal tubule that begins from the enlarged segment of the ascending limb of the LOOP OF HENLE. It reenters the KIDNEY CORTEX and forms the convoluted segments of the distal tubule.	Distal Kidney Tubule,Distal Renal Tubule,Distal Kidney Tubules,Distal Renal Tubules,Kidney Tubule, Distal,Renal Tubule, Distal,Renal Tubules, Distal,Tubule, Distal Kidney,Tubule, Distal Renal,Tubules, Distal Kidney,Tubules, Distal Renal
D008138	Loop of Henle	The U-shaped portion of the renal tubule in the KIDNEY MEDULLA, consisting of a descending limb and an ascending limb. It is situated between the PROXIMAL KIDNEY TUBULE and the DISTAL KIDNEY TUBULE.	Ascending Limb of Loop of Henle,Descending Limb of Loop of Henle,Henle Loop
D008722	Methods	A series of steps taken in order to conduct research.	Techniques,Methodological Studies,Methodological Study,Procedures,Studies, Methodological,Study, Methodological,Method,Procedure,Technique
D010281	Parathyroid Hormone	A polypeptide hormone (84 amino acid residues) secreted by the PARATHYROID GLANDS which performs the essential role of maintaining intracellular CALCIUM levels in the body. Parathyroid hormone increases intracellular calcium by promoting the release of CALCIUM from BONE, increases the intestinal absorption of calcium, increases the renal tubular reabsorption of calcium, and increases the renal excretion of phosphates.	Natpara,PTH (1-84),PTH(1-34),Parathormone,Parathyrin,Parathyroid Hormone (1-34),Parathyroid Hormone (1-84),Parathyroid Hormone Peptide (1-34),Hormone, Parathyroid
D010477	Perfusion	Treatment process involving the injection of fluid into an organ or tissue.	Perfusions
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.
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation