scholarly journals Favism: disordered erythrocyte calcium homeostasis

Blood ◽  
1985 ◽  
Vol 66 (2) ◽  
pp. 294-297 ◽  
Author(s):  
A De Flora ◽  
U Benatti ◽  
L Guida ◽  
G Forteleoni ◽  
T Meloni
Keyword(s):  
Atpase Activity ◽  
Intracellular Calcium ◽  
Calcium Homeostasis ◽  
Calcium Content ◽  
Calcium Atpase ◽  
Potassium Content ◽  
Hemolytic Crisis ◽  
The Mean ◽  
Fava Beans

Abstract The biochemical events that take place during acute hemolysis of G6PD- deficient subjects in favism are far from being elucidated. Evidence is here reported for a constantly and heavily disordered calcium homeostasis in the erythrocytes from seven favic patients. The abnormality, ie, a significantly impaired calcium ATPase activity and a parallel marked increase of intracellular calcium levels, was characteristic of the acute hemolytic crisis although unrelated to the attendant reticulocytosis. Concomitantly, a remarkable decrease of intracellular potassium was also observed. The mean +/- SD Ca2+-ATPase activity in the favic patients was 20.8 +/- 7.8 mumol Pi/g Hb/h compared with 37.2 +/- 8.5 in the matched controls represented by 12 healthy G6PD-deficient subjects (P less than .001). The mean +/- SD intraerythrocytic calcium content was 288 +/- 158 mumol/L of erythrocytes in the favic patients as compared with 22.0 +/- 8.2 in the G6PD-deficient controls (P less than .001). The intraerythrocytic potassium content was 76.6 +/- 19.3 mmol/L of erythrocytes in the favic patients and 106.6 +/- 8.2 in the G6PD-deficient controls (P less than .001). In vitro incubation of normal and G6PD-deficient erythrocytes with divicine, a pyrimidine aglycone present in fava beans and strongly implicated in the pathogenesis of favism, reproduces most of these events, including drop of calcium ATPase, increased intracellular calcium, and leakage of erythrocyte potassium.

scholarly journals Favism: disordered erythrocyte calcium homeostasis

Blood ◽  
1985 ◽  
Vol 66 (2) ◽  
pp. 294-297
Author(s):  
A De Flora ◽  
U Benatti ◽  
L Guida ◽  
G Forteleoni ◽  
T Meloni
Keyword(s):  
Atpase Activity ◽  
Intracellular Calcium ◽  
Calcium Homeostasis ◽  
Calcium Content ◽  
Calcium Atpase ◽  
Potassium Content ◽  
Hemolytic Crisis ◽  
The Mean ◽  
Fava Beans

The biochemical events that take place during acute hemolysis of G6PD- deficient subjects in favism are far from being elucidated. Evidence is here reported for a constantly and heavily disordered calcium homeostasis in the erythrocytes from seven favic patients. The abnormality, ie, a significantly impaired calcium ATPase activity and a parallel marked increase of intracellular calcium levels, was characteristic of the acute hemolytic crisis although unrelated to the attendant reticulocytosis. Concomitantly, a remarkable decrease of intracellular potassium was also observed. The mean +/- SD Ca2+-ATPase activity in the favic patients was 20.8 +/- 7.8 mumol Pi/g Hb/h compared with 37.2 +/- 8.5 in the matched controls represented by 12 healthy G6PD-deficient subjects (P less than .001). The mean +/- SD intraerythrocytic calcium content was 288 +/- 158 mumol/L of erythrocytes in the favic patients as compared with 22.0 +/- 8.2 in the G6PD-deficient controls (P less than .001). The intraerythrocytic potassium content was 76.6 +/- 19.3 mmol/L of erythrocytes in the favic patients and 106.6 +/- 8.2 in the G6PD-deficient controls (P less than .001). In vitro incubation of normal and G6PD-deficient erythrocytes with divicine, a pyrimidine aglycone present in fava beans and strongly implicated in the pathogenesis of favism, reproduces most of these events, including drop of calcium ATPase, increased intracellular calcium, and leakage of erythrocyte potassium.

Calcium ATPase and intestinal calcium transport in uremic rats

1980 ◽  
Vol 238 (5) ◽  
pp. G424-G428
Author(s):  
H. Schiffl ◽  
U. Binswanger
Keyword(s):  
Enzyme Activity ◽  
Atpase Activity ◽  
Calcium Transport ◽  
Calcium Atpase ◽  
Intestinal Calcium Transport ◽  
Identical Response ◽  
Close Relationship ◽  
Intact Rats

Calcium ATPase, an enzyme involved in intestinal calcium transport, was measured in homogenates of duodenal mucosal scrapings of normal and uremic rats. The effects of calcium deprivation and treatment with 1 alpha,25-dihydroxycholecalciferol [1,25-(OH)2D3] were investigated as well. Uremia decreased the enzyme activity and impaired the rise after calcium deprivation as observed in intact rats. The 1,25-(OH)2D3 treatment increased the enzyme activity in uremic animals and resulted in an identical response to calcium deprivation as observed in intact rats; parathyroidectomy abolished this effect. A striking correlation between everted duodenal gut sac calcium transport and calcium ATPase activity could be demonstrated for all groups of rats studied. It is concluded that the calcium ATPase activity is linked to the production of 1,25-(OH)2D3 as well as to an additional factor, probably parathyroid hormone. The close relationship between enzyme activity and in vitro calcium transport, even during constant physiological supplementation with 1,25-(OH)2D3, suggests an autonomous role of the calcium ATPase activity for mediation of calcium transport in the duodenum in addition to the well-known mechanisms related to vitamin D and its metabolites.

Abnormal response to calmodulin in vitro of dystrophic chicken muscle membrane calcium-ATPase activity

Biochemistry ◽  
1988 ◽  
Vol 27 (19) ◽  
pp. 7519-7524 ◽  
Author(s):  
Jose Galindo ◽  
Michael S. Hudecki ◽  
Faith B. Davis ◽  
Paul J. Davis ◽  
Harshad R. Thacore ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Calcium Atpase ◽  
Muscle Membrane ◽  
Chicken Muscle ◽  
Abnormal Response ◽  
Dystrophic Chicken

scholarly journals Alteration of protein localization and intracellular calcium content due to connexin26 D50A and A88V mutations

2017 ◽  
Vol 42 (2) ◽  
Author(s):  
Hande Aypek ◽  
Gülistan Meşe
Keyword(s):  
Golgi Apparatus ◽  
Intracellular Calcium ◽  
Cellular Localization ◽  
Protein Localization ◽  
Fluorescent Microscopy ◽  
Calcium Content ◽  
Immunofluorescent Staining ◽  
Cellular Mechanisms ◽  
Mutant Proteins

AbstractIntroduction:Connexins (Cx) play essential roles in cellular homeostasis by forming gap junctions and non-junctional hemichannels. In vitro characterization of Cx26 mutations causing keratitis-ichthyosis-deafness (KID) syndrome, were shown to form leaky hemichannels. The molecular/cellular mechanisms affected by aberrant hemichannels have recently been elucidated. Here, we further wanted to characterize Cx26 KID syndrome mutations, D50A and A88V, which were shown to form aberrant hemichannels and remained unaddressed in the literature.Methods:Neurobiotin uptake assay in HeLa and N2A cells transfected with Cx26-WT, D50A or A88V verified the presence of aberrant hemichannels and immunofluorescent staining with fluorescent microscopy determined cellular localization of Cx26. Finally, intracellular calcium content was examined by using calcium indicator, Fluo-3AM, and flow cytometer.Results:Cx26-D50A and A88V mutations prevented the formation of gap junction plaques at cell-cell appositions and mutant proteins were observed to localize to the Golgi apparatus. Further, comparison of intracellular calcium content showed an increase in calcium amount in cells containing Cx26-D50A and A88V relative to Cx26-WT.Conclusion:Retention of Cx26 in the Golgi apparatus and alteration in the intracellular calcium content due to KID syndrome mutations may influence various cellular processes that might contribute to development of epidermal phenotypes.

scholarly journals Artemisinin Induces Calcium-Dependent Protein Secretion in the Protozoan Parasite Toxoplasma gondii

2007 ◽  
Vol 6 (11) ◽  
pp. 2147-2156 ◽  
Author(s):  
Kisaburo Nagamune ◽  
Wandy L. Beatty ◽  
L. David Sibley
Keyword(s):  
Endoplasmic Reticulum ◽  
Toxoplasma Gondii ◽  
Intracellular Calcium ◽  
Protein Secretion ◽  
Calcium Homeostasis ◽  
Drug Targets ◽  
Calcium Oscillations ◽  
Calcium Atpase ◽  
Host Cells ◽  
Calcium Dependent

ABSTRACT Intracellular calcium controls several crucial cellular events in apicomplexan parasites, including protein secretion, motility, and invasion into and egress from host cells. The plant compound thapsigargin inhibits the sarcoplasmic-endoplasmic reticulum calcium ATPase (SERCA), resulting in elevated calcium and induction of protein secretion in Toxoplasma gondii. Artemisinins are natural products that show potent and selective activity against parasites, making them useful for the treatment of malaria. While the mechanism of action is uncertain, previous studies have suggested that artemisinin may inhibit SERCA, thus disrupting calcium homeostasis. We cloned the single-copy gene encoding SERCA in T. gondii (TgSERCA) and demonstrate that the protein localizes to the endoplasmic reticulum in the parasite. In extracellular parasites, TgSERCA partially relocalized to the apical pole, a highly active site for regulated secretion of micronemes. TgSERCA complemented a calcium ATPase-defective yeast mutant, and this activity was inhibited by either thapsigargin or artemisinin. Treatment of T. gondii with artemisinin triggered calcium-dependent secretion of microneme proteins, similar to the SERCA inhibitor thapsigargin. Artemisinin treatment also altered intracellular calcium in parasites by increasing the periodicity of calcium oscillations and inducing recurrent, strong calcium spikes, as imaged using Fluo-4 labeling. Collectively, these results demonstrate that artemisinin perturbs calcium homeostasis in T. gondii, supporting the idea that Ca2+-ATPases are potential drug targets in parasites.

Changes of intracellular calcium homeostasis in brain cortical structures during anoxia in vivo and in vitro

Resuscitation ◽  
1987 ◽  
Vol 15 (4) ◽  
pp. 245-255 ◽  
Author(s):  
Jerzy W. Lazarewicz ◽  
Mikchail O. Samoilov ◽  
Dmitry G. Semenov
Keyword(s):  
Intracellular Calcium ◽  
Calcium Homeostasis ◽  
Intracellular Calcium Homeostasis
Sign in / Sign up

Export Citation Format

Share Document