scholarly journals Binding of parathyroid hormone to bovine kidney-cortex plasma membranes

1973 ◽  
Vol 134 (4) ◽  
pp. 913-921 ◽  
Author(s):  
H. S. Sutcliffe ◽  
T. J. Martin ◽  
J. A. Eisman ◽  
R. Pilczyk

1. Plasma membranes were purified from bovine kidney cortex, with a fourfold increase in specific activity of parathyroid hormone-sensitive adenylate cyclase over that in the crude homogenate. The membranes were characterized by enzyme studies. 2. Parathyroid hormone was labelled with 125I by an enzymic method and the labelled hormone shown to bind to the plasma membranes and to be specifically displaced by unlabelled hormone. Parathyroid hormone labelled by the chloramine-t procedure showed no specific binding. 75Se-labelled human parathyroid hormone, prepared in cell culture, also bound to the membranes. 3. Parathyroid hormone was shown to retain biological activity after iodination by the enzymic method, but no detectable activity remained after chloramine-t treatment. 4. High concentration of pig insulin inhibited binding of labelled parathyroid hormone to plasma membranes and partially inhibited the hormone-sensitive adenylate cyclase activity in a crude kidney-cortex preparation. 5. EDTA enhanced and Ca2+ inhibited binding of labelled parathyroid hormone to plasma membranes. 6. Whereas rat kidney homogenates were capable of degrading labelled parathyroid hormone to trichloroacetic acid-soluble fragments, neither crude homogenates nor purified membranes from bovine kidney showed this property. 7. Binding of parathyroid hormone is discussed in relation to metabolism and initial events in hormone action.

1974 ◽  
Vol 63 (2) ◽  
pp. 369-375 ◽  
Author(s):  
T. J. MARTIN ◽  
N. VAKAKIS ◽  
J. A. EISMAN ◽  
S. J. LIVESEY ◽  
G. W. TREGEAR

SUMMARY Adenylate cyclase activity of crude plasma membranes from chick kidney was stimulated by low doses of parathyroid hormone (PTH). Sensitivity to PTH was ten to twenty times greater than that of a similar preparation from rat kidney cortex. Synthetic peptides consisting of the NH2-terminal 34 amino acids of bovine PTH (BPTH) and of human PTH (HPTH) were assayed, as were several analogues of these peptides. Bovine PTH (1–34) and HPTH (1–34) were equivalent in their action on chick kidney but the human peptide had only 20% of the activity of the bovine peptide on rat kidney cortex adenylate cyclase. Bovine proPTH ( −6→ + 34) and (Tyr1)-BPTH (1–34) had less activity than BPTH (1–34). Bovine PTH (2–34) inhibited the response to BPTH (1–34). Neither salmon calcitonin nor vasopressin stimulated adenylate cyclase activity.


1972 ◽  
Vol 54 (2) ◽  
pp. 232-245 ◽  
Author(s):  
Hans-G Heidrich ◽  
Rolf Kinne ◽  
Eva Kinne-Saffran ◽  
Kurt Hannig

Two different membrane fractions were obtained from a brush-border fraction of rat kidney cortex by using their different electrical surface charges in preparative free-flow electrophoresis. One membrane fraction contained only morphologically intact microvilli and was characterized by a high specific activity of alkaline phosphatase. The other fraction morphologically resembled classical plasma membranes by possessing junctional complexes and a high Na-K-ATPase activity The contamination of the isolated membrane fractions by other cell organelles was extremely low These two fractions represent the apical (luminal) and the basal (interstitial) area of the renal proximal tubule cell membrane and clearly demonstrate the polarity of this cell.


1991 ◽  
Vol 261 (6) ◽  
pp. F1063-F1070
Author(s):  
A. Gupta ◽  
B. Bastani ◽  
P. Chardin ◽  
K. A. Hruska

Plasma membranes from bovine kidney cortex were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and transferred to nitrocellulose membranes. Blotting with [alpha-32P]GTP and [35S]GTP gamma S demonstrated specific binding to three and six distinct protein bands, respectively, in the 20,000- to 29,000-Mr range. This indicated the presence of small Mr GTP binding proteins (smg) in bovine kidney cortex. Only one smg with 28,000 Mr was labeled with hydrolysis-resistant GTP photoaffinity probe p3-(4-azidoanilido)-p1-5GTP (AAGTP). The major smg in platelet membranes that binds GTP on nitrocellulose blots has been identified as ral-Mr 29,000. With the use of an antiserum against the ral A gene product, one of the smg with Mr of 29,000 present in bovine renal cortical plasma membranes was identified as ral. Ral was absent from glomerular homogenate, suggesting that it is localized to the tubular segments of the nephron. Ral was detected only in the particulate fraction and not the cytosol. Further subcellular localization of ral was investigated by immunohistochemical staining. Anti-ral antibody immunostained the apical and basolateral membranes of cells in the cortical and medullary collecting ducts in a speckled pattern in the bovine kidney. In the rat kidney, however, uniform linear staining of cortical and medullary collecting ducts predominantly localized to the apical membrane was observed. To date, no function has been assigned to ral. Localization of the ral gene product to the collecting duct suggests a specific functional role for this GTP-binding protein.


1975 ◽  
Vol 24 (1) ◽  
pp. 131-144 ◽  
Author(s):  
Linda J. Shlatz ◽  
Irving L. Schwartz ◽  
Evamaria Kinne-Saffran ◽  
Rolf Kinne

1980 ◽  
Vol 93 (3) ◽  
pp. 339-345 ◽  
Author(s):  
Naokazu Nagata ◽  
Yuriko Ono ◽  
Narimichi Kimura

Abstract. The interaction between parathyroid hormone (PTH) and prostaglandin E1 (PGE1) in influencing cyclic AMP metabolism in rat renal cortical tissue was examined. PTH and PGE1 stimulated additively the adenylate cyclase activity in the homogenate of the tissue. Both PTH and PGE1 enhanced the level of cyclic AMP in the incubated renal cortical tissue, but the effect of their simultaneous addition did not exceed the effect induced by PTH alone. Cyclic AMP accumulated in the incubation medium by stimulation by PTH was decreased by the simultaneous addition of PGE1. When the tissue was pre-incubated for 30 min with 2 to 10 μg/ml of PGE1, the magnitude of the increase of cyclic AMP caused by PTH subsequently added was lessened. However, the response to PTH of adenylate cyclase preparation obtained from the homogenate of PGE1-pre-treated tissue was not decreased. When first PTH was added to the incubating renal cortical tissue, the subsequent addition of PGE1 accelerated the decrease of cyclic AMP content in the tissue and decreased the amount of cyclic AMP released from the tissue. The interaction of PTH and PGE1 on cyclic AMP metabolism in the renal cortical tissue was in contrast to that seen in newborn rat calvaria where PGE1 and PTH acted additively in enhancing the level of cyclic AMP.


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