Experimental diabetes attenuates calcium mobilization and proliferative response in splenic lymphocytes from mice.
The present study was conducted to investigate the effects of the diabetic condition on cytosolic free Ca(2+) concentration, [Ca(2+)](i), and the proliferation of splenic lymphocytes from mice. Diabetes was induced in mice by intraperitoneal injection of alloxan. [Ca(2+)](i) and the proliferation ex vivo of splenic lymphocytes isolated from mice were examined using fura-2 and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide, respectively. Diabetes caused a significant increase in resting [Ca(2+)](i) and significantly reduced the ability of concanavalin A (Con A; a T-lymphocyte-selective mitogen) to increase [Ca(2+)](i), but not that of lipopolysaccharide (LPS; a B-lymphocyte-selective mitogen). In addition, diabetes significantly reduced Con A-stimulated but not LPS-stimulated lymphocyte proliferation. Verapamil (an L-type Ca(2+) channel blocker) inhibited Con A-induced increases in [Ca(2+)](i) and proliferation in lymphocytes from control and diabetic mice to a similar extent, respectively. These results suggest that diabetes attenuates Con A-stimulated T-lymphocyte proliferation by decreasing [Ca(2+)](i) via reduction of Ca(2+) entry through L-type Ca(2+) channels.
Research Center for Animal Hygiene and Food Safety, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Japan. es@obihiro.ac.jp
Eiki
E
Satoh
Ryota
R
Iwasaki
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D002118:Calcium / Q000378:metabolism*; D020746:Calcium Channels, L-Type / Q000378:metabolism*; D003208:Concanavalin A / Q000037:antagonists & inhibitors / Q000494:pharmacology; D003921:Diabetes Mellitus, Experimental / Q000276:immunology* / Q000378:metabolism*; D016257:Fura-2 / Q000737:chemistry; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D008214:Lymphocytes / Q000187:drug effects* / Q000276:immunology; D008297:Male; D051379:Mice; D013154:Spleen / Q000187:drug effects* / Q000378:metabolism; D013778:Tetrazolium Salts / Q000737:chemistry; D013844:Thiazoles / Q000737:chemistry; D014700:Verapamil / Q000494:pharmacology
D001786:Blood Glucose; D020746:Calcium Channels, L-Type; D008070:Lipopolysaccharides; D013778:Tetrazolium Salts; D013844:Thiazoles; C082161:lipopolysaccharide A; D003208:Concanavalin A; D014700:Verapamil; C022616:thiazolyl blue; D002118:Calcium; D016257:Fura-2