The effect of endogenous parathyroid hormone, exogenous calcitonin, and dibutyryl cyclic AMP on urinary excretion of N-acetyl-?-D-glucosaminidase

1994 ◽  
Vol 54 (3) ◽  
pp. 186-194 ◽  
Author(s):  
K. Mizunashi ◽  
Y. Furukawa ◽  
K. Yoshinaga
Keyword(s):  
Parathyroid Hormone ◽  
Cyclic Amp ◽  
Urinary Excretion ◽  
Dibutyryl Cyclic Amp

Renal metabolism of N6,O2'-dibutyryl adenosine 3',5'-monophosphate

1979 ◽  
Vol 237 (1) ◽  
pp. F75-F84
Author(s):  
R. Coulson ◽  
W. W. Harrington
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Urinary Excretion ◽  
Rat Kidney ◽  
Bond Cleavage ◽  
Dibutyryl Cyclic Amp ◽  
Renal Metabolism ◽  
Phosphate Bond ◽  
Isolated Rat

Metabolism of dibutyryl cyclic AMP was studied by including the 3H- or C-labeled nucleotide (0.1 mM, 5 mumol) in the recirculating perfusate of the isolated rat kidney. Kidneys were perfused with nucleotide for 60 min. Dibutyryl cyclic AMP was almost completely cleared from the perfusate, about one-quarter as urinary excretion principally by probenecid-sensitive secretion and about one-half as metabolism beyond 3'-phosphate bond cleavage. The principal metabolite, N6-monobutyryl adenosine, accounted for one-third of added dibutyryl cyclic AMP. The remaining metabolites were ATP, ADP AMP, and N6-monobutyryl AMP. Dibutyryl cyclic AMP (0.1 or 1.0 mM) elevated renal ATP but did not alter uricogenesis. Both dibutyryl cyclic AMP and cyclic AMP at 0.2 mM produced similar activation and subcellular redistribution of renal protein kinase. N6-monobutyryl adenosine, unlike adenosine, had no effect on the renal activity of adenylate cyclase, low Km cyclic AMP phosphodiesterase, and protein kinase. Dibutyryl cyclic AMP is like exogenous cyclic AMP in that it penetrates the rat kidney, activates protein kinase, and is metabolized to ATP (R. Coulson, J. Biol. Chem. 251: 4958-4967, 1976), but is unlike cyclic AMP in its extent of secretion and metabolism to ATP and urate and in its formation of the unique metabolites N6-monobutyryl AMP and N6-monobutyryl adenosine.

scholarly journals Effect of administration of the fructose on the glycogenolytic action of glucagon. An investigation of the pathogeny of hereditary fructose intolerance

1973 ◽  
Vol 134 (2) ◽  
pp. 637-645 ◽  
Author(s):  
G. Van Den Berghe ◽  
L. Hue ◽  
H. G. Hers
Keyword(s):  
Blood Glucose ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Urinary Excretion ◽  
Fold Increase ◽  
Maximal Effect ◽  
Dibutyryl Cyclic Amp ◽  
Hereditary Fructose Intolerance ◽  
Fructose Intolerance ◽  
Km Value

1. The mechanism by which the administration of fructose to patients with hereditary fructose intolerance makes them unresponsive to the hyperglycaemic action of glucagon was studied. In four patients, a 10-fold increase in the urinary excretion of cyclic AMP was induced by glucagon, but this effect was drastically decreased by the previous administration of fructose (250mg/kg). Further, the intravenous injection of 6-N,2′-O-dibutyryl cyclic AMP did not cause an increase in the blood glucose during fructose-induced hypoglycaemia. 2. The administration of a large dose of fructose (5g/kg) to mice decreased markedly both the concentration of ATP and the increase in the concentration of cyclic AMP caused by glucagon in the liver. Other ATP-depleting agents had a similar effect and a linear correlation could be drawn between the concentration of ATP and the change in cyclic AMP concentration; a half-maximal effect was obtained for a concentration of ATP close to the Km value of adenylate cyclase. 3. The administration of fructose to mice caused the inactivation of phosphorylase in the liver, but this effect was easily reversed by glucagon. 4. At a concentration of 10mm-fructose 1-phosphate and 1.5mm-Pi, purified liver phosphorylase a was inhibited by 70%. This inhibition appears to be a likely explanation for the unresponsiveness to glucagon of patients with hereditary fructose intolerance.

Impaired renal response to parathyroid hormone in potassium depletion

1975 ◽  
Vol 228 (1) ◽  
pp. 179-183 ◽  
Author(s):  
N Beck ◽  
BB Davis
Keyword(s):  
Parathyroid Hormone ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Renal Cortex ◽  
Rat Kidney ◽  
Potassium Depletion ◽  
Dibutyryl Cyclic Amp ◽  
Renal Response ◽  
Proximal Tubular ◽  
Urinary Cyclic Amp

In potassium depletion, a possible alteration of the proximal tubular response to parathyroid hormone (PTH) was evaluated in rat kidney. 1) There were impairments of both phosphaturic and urinary cyclic AMP responses to PTH. The site of the impairment was further investigated by studying the PTH-dependent cycle AMP system in renal cortex. 2) There was a lesser increase of cyclic AMP concentration by PTH in potassium-depleted slices, indicating the lesser urinary cyclic AMP was due to the specific impairment of PTH-dependent cyclic AMP in the kidney. 3). The activation of adenylate cyclase by PTH was impaired , but phosphodiesterase activity was not affected by potassium depletion, indicating the impairment of cyclic AMP generation was due to inhibition of adenylate cyclase. 4) The phosphaturic response to dibutyryl cyclic AMP infusion was also significantly less in the potassium-depleted animals, indicating the step subsquent to the cyclic AMP generation is also impaired. All above results indicate that, in potassium depletion, the renal response to PTH is impaired, and the impairment is both within the step of cyclic AMP generation and after the cyclic AMP generation.

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