[Influence of calcium concentration on 4-aminopyridine induced histamine release from isolated peritoneal mast cells].
4-Aminopyridine (4-AP) has been shown to induce histamine release from isolated peritoneal mast cells (PMC) in mice and rats. In the presence of extracellular calcium at normal level (0.9 mmol.L-1) histamine release induced by 4-AP (13.6 mmol.L-1) from mice PMC was 33.0% +/- 4.6%, while at low calcium concentration (0.5 mmol.L-1) and in calcium-free medium this parameter decreased to 25.5% +/- 4.2% and 16.3% +/- 3.7% respectively. Histamine release in response to 4-AP (10 mmol.L-1) from rat PMC was 39.1% +/- 6.7% (0.9 mmol.L-1 calcium), while at low calcium concentration (0.5 mmol.L-1) and in calcium-free medium this parameter decreased to 29.3% +/- 4.7% and 20.2% +/- 2.9% respectively. Results of statistical analysis indicate that 4-AP induced histamine release is related to Ca2+ concentration. When rat PMC were preincubated in calcium-free medium with EDTA 0.1 mmol.L-1 for 180 min 4-AP induced histamine release was 13.8% +/- 1.6%. This shows that 4-AP also elicited mobilization of endogenous calcium stores in mast cells. The mechanism of 4-AP induced histamine release was discussed.
Xu
J H
JH
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Zhejiang Medical University, Hangzhou.
Wang
P
P
Chen
Z G
ZG
Zhang
J X
JX
D015761:4-Aminopyridine / Q000494:pharmacology*; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D005260:Female; D006636:Histamine Release / Q000187:drug effects*; D008297:Male; D008407:Mast Cells / Q000378:metabolism*; D051379:Mice; D010529:Peritoneal Cavity / Q000166:cytology; D051381:Rats; D017207:Rats, Sprague-Dawley
D015761:4-Aminopyridine; D002118:Calcium