Calcium ion transients in neutrophils from patients with sporadic Alzheimer's disease.
Abnormalities involving intracellular calcium homeostasis have been detected in Alzheimer's disease brain and fibroblasts as well as presenilin-1 mutation-bearing cells. In the present study we investigated inositol(1,4,5)trisphosphate-mediated calcium transients as well as calcium responses via mechanisms not related to surface receptors in Alzheimer's disease polymorphonuclear (PMN) granulocytes, using the tripeptide formyl-methionyl-leucyl-phenyl alanine (fMLP) and calcium ionophore ionomycin, respectively. fMLP elicited a biphasic response with an initial, fast increase in intracellular free calcium concentrations followed by a second, lower phase with no significant differences in either maximal response or time course between Alzheimer's disease granulocytes and controls. Similarly, the calcium signal elicited after ionomycin exposure was unchanged in Alzheimer's disease PMN. In conclusion, these results indicate that calcium mobilization from intracellular stores and via cross-membrane mechanisms is intact in Alzheimer's disease granulocytes.
Garlind
A
A
Department of Clinical Neuroscience and Family Medicine, Karolinska Institute, Huddinge University Hospital, Sweden.
Nilsson
E
E
Palmblad
J
J
D000368:Aged; D000544:Alzheimer Disease / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology*; D002118:Calcium / Q000378:metabolism*; D005260:Female; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism; D015759:Ionomycin / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D008297:Male; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D009994:Osmolar Concentration; D012016:Reference Values; D013997:Time Factors
D007476:Ionophores; D015759:Ionomycin; D009240:N-Formylmethionine Leucyl-Phenylalanine; D002118:Calcium