Role of G-proteins in the regulation of organic osmolyte efflux from isolated rat renal inner medullary collecting duct cells

1996 ◽  
Vol 433 (1-2) ◽  
pp. 35-41 ◽  
Author(s):  
Birgit Ruhfus ◽  
Hanna Tinel ◽  
R. K. H. Kinne
Keyword(s):  
G Proteins ◽  
Collecting Duct ◽  
Inner Medullary Collecting Duct ◽  
Organic Osmolyte ◽  
Duct Cells ◽  
Collecting Duct Cells ◽  
Medullary Collecting Duct ◽  
Osmolyte Efflux ◽  
Isolated Rat

Response of rat inner medullary collecting duct to epidermal growth factor

1989 ◽  
Vol 256 (6) ◽  
pp. F1117-F1124 ◽  
Author(s):  
R. C. Harris
Keyword(s):  
Growth Factor ◽  
Binding Sites ◽  
Collecting Duct ◽  
Affinity Binding ◽  
Inner Medullary Collecting Duct ◽  
Duct Cells ◽  
Epidermal Growth ◽  
Collecting Duct Cells ◽  
Medullary Collecting Duct

Urine is an abundant source of epidermal growth factor (EGF) and prepro-EGF has been localized to the thick ascending limb and distal convoluted tubule of the kidney. However, the functional role of EGF in the kidney is poorly understood. Determination of EGF receptors and functional responses to EGF in intrarenal structures distal to the site of renal EGF production may prove critical to our understanding of the role of this peptide. These studies were designed to investigate the response to EGF of rat inner medullary collecting duct cells in culture and in freshly isolated suspensions. Primary cultures of inner medullary collecting duct cells demonstrated equilibrium binding of 125I-labeled EGF at 4 and 23 degrees C. At 23 degrees C, there was 89 +/- 1% specific binding (n = 30). Scatchard analysis of 125I-EGF binding suggested the presence of both high-affinity binding with a dissociation constant (Kd) of 5 X 10(-10) M and maximal binding sites (Ro) of 2.7 X 10(3) binding sites/cell and low-affinity binding, with Kd of 8.3 X 10(-9) M and Ro of 1.8 X 10(4) binding sites/cell. Bound EGF, 68 +/- 3%, was internalized by 45 min. EGF binding was not inhibited by antidiuretic hormone, atrial natriuretic peptide or bradykinin at 23 degrees C, but there was concentration-dependent inhibition of binding by transforming growth factor-alpha. Incubation with phorbol myristate acetate decreased 125I-EGF binding in a concentration-dependent manner. 125I-EGF binding was also demonstrated in freshly isolated suspensions of rat inner medullary collecting duct cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of [Ca2+]i in lethal oxidative injury in rat cultured inner medullary collecting duct cells

1995 ◽  
Vol 430 (5) ◽  
pp. 697-704 ◽  
Author(s):  
Yutaka Kuroda ◽  
Katsuji Takeda ◽  
Kaoru Tabei ◽  
Masatoshi Kuroki ◽  
Toshio Yagimuma ◽  
...  
Keyword(s):  
Collecting Duct ◽  
Oxidative Injury ◽  
Inner Medullary Collecting Duct ◽  
Duct Cells ◽  
Collecting Duct Cells ◽  
Medullary Collecting Duct
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