Lactic acid and steroid production by intact mouse adrenal glands and cell suspensions: effects of nucleotide derivatives and substrates

1985 ◽  
Vol 104 (1) ◽  
pp. 105-111 ◽  
Author(s):  
J. Hinson ◽  
M. K. Birmingham

ABSTRACT The effects of the dibutyryl derivatives of cyclic GMP and cyclic AMP on lactic acid and steroid production were compared in intact mouse adrenal glands at concentrations of 0·5–1 mmol/l and in mouse adrenal cell suspensions at concentrations of 0·01–1 mmol/l. The dibutyryl derivative of cyclic GMP had little or no effect on lactic acid production in either tissue preparation. It caused a slight stimulation of corticosteroid output in intact glands at a concentration of 1 mmol/l, amounting to one-tenth of the response observed with 1 mm-dibutyryl cyclic AMP. Dose-dependent increases in lactic acid and steroid production were obtained with dibutyryl cyclic AMP in cell suspensions. AMP and GMP increased lactic acid but not steroid production. All the substrates tested (glucose, glucose-6-phosphate, fructose, fructose-6-phosphate, fructose-1,6-diphosphate, 10 mmol/l; pyruvate and glycerol, 20 mmol/l) stimulated basal glycolysis in intact glands and cell suspensions and none affected basal steroid production significantly. By far the greatest increase in lactic acid production was noted with fructose-1,6-diphosphate. However, only glucose and, in unsectioned glands, pyruvate exerted a potentiating effect on the glycolytic response to ACTH. Glucose potentiated the steroidogenic response to ACTH also, but only in intact glands. The relative ineffectiveness of dibutyryl cyclic GMP is in accord with the species-dependent differing responses to the free form of the cyclic nucleotides noted in mouse and rat adrenal glands. The substrate requirements are in keeping with a rate-limiting role of phosphofructokinase and an action of ACTH at some site between the entry of glucose into the cell and the formation of fructose-1,6-diphosphate. J. Endocr. (1985) 104, 105–111

1981 ◽  
Vol 91 (3) ◽  
pp. 447-456 ◽  
Author(s):  
W.-T. HUM ◽  
A. BARTA-BARTOVA ◽  
M. K. BIRMINGHAM

The effects of nucleotides and nucleosides on steroidogenesis and aerobic lactic-acid production were examined in unsectioned mouse adrenal glands preincubated for 1 h and then incubated for 2 h in Krebs–Ringer bicarbonate and 0·01 m-glucose medium equilibrated with 95% O2:5% CO2. Of all the compounds tested, at a concentration of 10 mmol/l (cyclic AMP, cyclic GMP, AMP, ADP, ATP, GMP, IMP, adenosine, guanosine and inosine), only cyclic AMP was capable of stimulating steroidogenesis and induced a nine- to 12-fold increase in corticosterone production. Cyclic GMP inhibited corticosterone production by 40–55%. The nucleotides and nucleosides, except for ATP, all increased lactic-acid production. Cyclic AMP caused a three- to fivefold stimulation, cyclic GMP an increase of only 20–30%, and GMP, AMP and ADP increases of 80–100%. Cyclic GMP, protected from hydrolysis, may thus inhibit lactic-acid as well as steroid production in the mouse adrenal gland. By contrast, cyclic GMP was nearly as effective as cyclic AMP in stimulating glycolysis and steroidogenesis of rat adrenal glands. The proportion of corticosterone to 18-hydroxydeoxycorticosterone (18-OH-DOC) obtained with cyclic GMP was, however, always lower than that obtained with cyclic AMP. Cyclic AMP, as opposed to cyclic GMP, increased the formation of corticosterone and lactic acid in the presence of exogenous deoxycorticosterone (DOC) beyond that expected from an additive response. Lactic-acid production was inhibited by 18-OH-DOC, a major secretory product of the rat but not the mouse adrenal. This steroid, furthermore, greatly reduced the stimulation of glycolysis evoked by added DOC, 11β-hydroxyprogesterone and corticosterone, facts that could account for the greater glycolytic activity of mouse compared with rat adrenals. The yield of corticosterone in the presence of added 11β-hydroxyprogesterone, but not of DOC, was also reduced by 18-OH-DOC, denoting a selective inhibition of 21-hydroxylation. A structural analogue of 18-OH-DOC, 18,20-cyclo-20,21-dihydroxypregn-4-en-3-one, added by itself stimulated lactic-acid production. Added in combination with other steroids, it specifically counteracted the inhibitory effect of 18-OH-DOC, a steroid of potentially adverse biological properties. Our results are compatible with the concept that adrenal aerobic glycolysis is to a significant extent, but not exclusively, steroid-mediated. The glycolytically active but steroidogenically inert nucleotides and nucleosides offer examples of a dissociation between the two events.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Beatriz Martines de Souza ◽  
Mayara Souza Silva ◽  
Aline Silva Braga ◽  
Patrícia Sanches Kerges Bueno ◽  
Paulo Sergio da Silva Santos ◽  
...  

AbstractThis in vitro study evaluated the protective effect of titanium tetrafluoride (TiF4) varnish and silver diamine fluoride (SDF) solution on the radiation-induced dentin caries. Bovine root dentin samples were irradiated (70 Gy) and treated as follows: (6 h): 4% TiF4 varnish; 5.42% NaF varnish; 30% SDF solution; placebo varnish; or untreated (negative control). Microcosm biofilm was produced from human dental biofilm (from patients with head-neck cancer) mixed with McBain saliva for the first 8 h. After 16 h and from day 2 to day 5, McBain saliva (0.2% sucrose) was replaced daily (37 °C, 5% CO2) (biological triplicate). Demineralization was quantified by transverse microradiography (TMR), while biofilm was analyzed by using viability, colony-forming units (CFU) counting and lactic acid production assays. The data were statistically analyzed by ANOVA (p < 0.05). TiF4 and SDF were able to reduce mineral loss compared to placebo and the negative control. TiF4 and SDF significantly reduced the biofilm viability compared to negative control. TiF4 significantly reduced the CFU count of total microorganism, while only SDF affected total streptococci and mutans streptococci counts. The varnishes induced a reduction in lactic acid production compared to the negative control. TiF4 and SDF may be good alternatives to control the development of radiation-induced dentin caries.


Heliyon ◽  
2021 ◽  
Vol 7 (5) ◽  
pp. e07079
Author(s):  
Joel Romial Ngouénam ◽  
Chancel Hector Momo Kenfack ◽  
Edith Marius Foko Kouam ◽  
Pierre Marie Kaktcham ◽  
Rukesh Maharjan ◽  
...  

2021 ◽  
Author(s):  
Xinpeng Zhao ◽  
Zhimin Zhou ◽  
hu luo ◽  
Yanfei Zhang ◽  
Wang Liu ◽  
...  

Combined experiments and density functional theory (DFT) calculations provided insights into the role of the environment-friendly γ-valerolactone (GVL) as a solvent in the hydrothermal conversion of glucose into lactic acid...


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