Effects of Parathyroid Hormone on Glucose Production by the Liver1

2015 ◽  
pp. 129-137
Author(s):  
Saulo Klahr ◽  
Keith Hruska ◽  
Kevin Martin
Keyword(s):  
Parathyroid Hormone ◽  
Glucose Production

Renal gluconeogenesis: axial and internephron heterogeneity and the effect of parathyroid hormone

1984 ◽  
Vol 246 (1) ◽  
pp. F59-F66 ◽  
Author(s):  
M. S. Wang ◽  
K. Kurokawa
Keyword(s):  
Parathyroid Hormone ◽  
Calcium Ions ◽  
Glucose Production ◽  
Cellular Responses ◽  
Nephron Segments ◽  
Renal Gluconeogenesis ◽  
The Difference ◽  
Proximal Tubule Segments ◽  
Camp Formation ◽  
Gluconeogenic Substrate

To better understand the regulation of renal gluconeogenesis that occurs in the proximal nephron, glucose production rates from various substrates were determined in defined proximal tubule segments of the rat. Tubule segments tested were the S1 and S2 segments of superficial (SF) nephrons, the S1 segments of juxtamedullary (JM) nephrons, and the S3 segments. Glucose production (in decreasing order) was: from alpha-ketoglutarate, JM S1, SF S1, SF S2; from pyruvate, SF S2, JM S1, and SF S1; from glutamine, SF S1, JM S1; and from glutamate, SF S1 = JM S1. Little glucose was produced in the S3 segments. Glucose production from glutamate was lower than that from the other three substrates in JM S1, and glutamine was the best gluconeogenic substrate in SF S1. The effects of parathyroid hormone (PTH), a known stimulator of renal gluconeogenesis, and cAMP were examined using alpha-ketoglutarate as the substrate. Both stimulated glucose production in the S1 and S2 segments of the SF nephron. Although PTH stimulated adenylate cyclase in the S1 segments of the SF and JM nephrons, it had no effect on glucose production in the JM S1. Glucose production rose in the SF S1 and JM S1 in response to increasing concentrations of hydrogen or calcium ions, indicating that gluconeogenesis can be increased in these nephron segments. Differences may therefore be present in the cellular responses to PTH distal to cAMP formation in the nephron segments of the SF and JM nephrons. These findings show the presence of both axial and internephron heterogeneity of renal gluconeogenesis and suggest the difference in the effects of PTH on the function of SF and JM nephrons.

scholarly journals Calcium rather than cyclic AMP is an intracellular messenger of parathyroid hormone action on glycogen metabolism in isolated rat hepatocytes

1989 ◽  
Vol 258 (3) ◽  
pp. 889-894 ◽  
Author(s):  
T Mine ◽  
I Kojima ◽  
E Ogata
Keyword(s):  
Parathyroid Hormone ◽  
Cyclic Amp ◽  
Glucose Production ◽  
Rat Hepatocytes ◽  
Free Calcium ◽  
Dependent Manner ◽  
Isolated Rat Hepatocytes ◽  
Glucose Output ◽  
Dose Dependent ◽  
Isolated Rat

The synthetic 1-34 fragment of human parathyroid hormone (1-34hPTH) stimulated glucose production in isolated rat hepatocytes. The effect of 1-34hPTH was dose-dependent and 10(10) M-1-34 hPTH elicited the maximum glucose output, which was approx. 80% of that by glucagon. Although 1-34hPTH induced a small increase in cyclic AMP production at concentrations higher than 10(-9) M, 10(-10) M-1-34hPTH induced the maximum glucose output without significant elevation of cyclic AMP. This is in contrast to the action of forskolin, which increased glucose output to the same extent as 10(-10) M-1-34hPTH by causing a 2-fold elevation of cyclic AMP. In addition to increasing cyclic AMP, 1-34hPTH caused an increase in cytoplasmic free calcium concentration ([Ca2+]c). When the effect of 1-34hPTH on [Ca2+]c was studied in aequorin-loaded cells, low concentrations of 1-34hPTH increased [Ca2+]c: the 1-34hPTH effect on [Ca2+]c was detected at as low as 10(-12) M and increased in a dose-dependent manner. 1-34hPTH increased [Ca2+]c even in the presence of 1 microM extracellular calcium, suggesting that PTH mobilizes calcium from an intracellular pool. In line with these observations, 1-34hPTH increased the production of inositol trisphosphate. These results suggest that: (1) PTH activates both cyclic AMP and calcium messenger systems and (2) PTH stimulates glycogenolysis mainly via the calcium messenger system.

scholarly journals Hormonal control of gluconeogenesis in tubule fragments from renal cortex of fed rats. Effects of α-adrenergic stimuli, glucagon, theophylline and papaverine

1977 ◽  
Vol 168 (1) ◽  
pp. 33-42 ◽  
Author(s):  
David W. R. MacDonald ◽  
E. David Saggerson
Keyword(s):  
Parathyroid Hormone ◽  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Cyclic Nucleotide ◽  
Renal Cortex ◽  
Glucose Production ◽  
Hormonal Control ◽  
Adrenergic Agonists ◽  
Renal Gluconeogenesis ◽  
Stimulation Of

1. In incubated tubule fragments from renal cortex of fed rats gluconeogenesis from pyruvate was stimulated by adrenaline (1μm optimum) and by the selective α-adrenergic agonists oxymetazoline and amidephrine. The selective β-agonists isoproterenol and salbutamol were ineffective at concentrations up to 10μm. 2. Stimulation of gluconeogenesis by 1μm-adrenaline was almost completely blocked by 10μm-phentolamine (α-antagonist), partially blocked by 10μm-phenoxybenzamine (α-antagonist) and unaffected by 10μm-propranolol (β-antagonist). 3. Adrenaline stimulation of gluconeogenesis was rapid and was sustained for at least 1h. 4. Oxymetazoline (α-agonist) was extremely potent in stimulation of gluconeogenesis. This compound stimulated glucose production from pyruvate, lactate and glutamate, but not from succinate or glycerol. 5. In the absence of Ca2+ oxymetazoline was ineffective, whereas some stimulatory effect of adrenaline on gluconeogenesis was still observed. 6. Glucagon had no effect on gluconeogenesis from pyruvate in the presence of 1.27mm-Ca2+ and inhibited the process in the presence of 0.25mm-Ca2+. Parathyrin (parathyroid hormone) stimulated gluconeogenesis at 1.27mm-Ca2+. 7. In short incubations of tubule fragments glucagon, papaverine and adrenaline significantly increased 3′:5′-cyclic AMP. Adrenaline also slightly decreased 3′:5′-cyclic GMP. Oxymetazoline had no effect on the amount of either cyclic nucleotide. 8. At all concentrations tested, theophylline and papaverine decreased gluconeogenesis from pyruvate. 9. It is concluded that renal gluconeogenesis may be increased by α- but not β-adrenergic stimuli and that this is probably independent of changes in 3′:5′-cyclic AMP or 3′:5′-cyclic GMP. An involvement of Ca2+ in the action of oxymetazoline appears likely, but this is less certain with adrenaline.

Two isoprenylated flavonoids from Dorstenia psilurus activate AMPK, stimulate glucose uptake, inhibit glucose production and lower glycemia

2019 ◽  
Vol 476 (24) ◽  
pp. 3687-3704 ◽  
Author(s):  
Aphrodite T. Choumessi ◽  
Manuel Johanns ◽  
Claire Beaufay ◽  
Marie-France Herent ◽  
Vincent Stroobant ◽  
...  
Keyword(s):  
Glucose Uptake ◽  
Human Cancer ◽  
Glucose Production ◽  
Liver Mitochondria ◽  
New Drugs ◽  
Structural Isomer ◽  
Rat Liver Mitochondria ◽  
Ionization Mass ◽  
Ampk Activation ◽  
Starting Point

Root extracts of a Cameroon medicinal plant, Dorstenia psilurus, were purified by screening for AMP-activated protein kinase (AMPK) activation in incubated mouse embryo fibroblasts (MEFs). Two isoprenylated flavones that activated AMPK were isolated. Compound 1 was identified as artelasticin by high-resolution electrospray ionization mass spectrometry and 2D-NMR while its structural isomer, compound 2, was isolated for the first time and differed only by the position of one double bond on one isoprenyl substituent. Treatment of MEFs with purified compound 1 or compound 2 led to rapid and robust AMPK activation at low micromolar concentrations and increased the intracellular AMP:ATP ratio. In oxygen consumption experiments on isolated rat liver mitochondria, compound 1 and compound 2 inhibited complex II of the electron transport chain and in freeze–thawed mitochondria succinate dehydrogenase was inhibited. In incubated rat skeletal muscles, both compounds activated AMPK and stimulated glucose uptake. Moreover, these effects were lost in muscles pre-incubated with AMPK inhibitor SBI-0206965, suggesting AMPK dependency. Incubation of mouse hepatocytes with compound 1 or compound 2 led to AMPK activation, but glucose production was decreased in hepatocytes from both wild-type and AMPKβ1−/− mice, suggesting that this effect was not AMPK-dependent. However, when administered intraperitoneally to high-fat diet-induced insulin-resistant mice, compound 1 and compound 2 had blood glucose-lowering effects. In addition, compound 1 and compound 2 reduced the viability of several human cancer cells in culture. The flavonoids we have identified could be a starting point for the development of new drugs to treat type 2 diabetes.

Abstract #191 Hallucinations and Paranoia in the Setting of an Intrathyroid Parathyroid Hormone Secreting Nodule

2019 ◽  
Vol 25 ◽  
pp. 56-57
Author(s):  
Robert Gaffey ◽  
Eric Pagan ◽  
Briette Karanfillian ◽  
Sahil Parikh ◽  
Ankit Shah
Keyword(s):  
Parathyroid Hormone
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