%0 Journal Article
%T Phenytoin-Induced Elevation of the Intracellular Calcium Concentration by Stimulation of Calcium-Sensing Receptors in Gingival Fibroblasts
%A Toshimi Hattori
%A Keisuke Nakano
%A Toshiyuki Kawakami
%J Pharmacology & Pharmacy
%P 261-265
%@ 2157-9431
%D 2013
%I Scientific Research Publishing
%R 10.4236/pp.2013.42037
%X <p class=\"MsoNormal\">
	<span lang=\"EN-US\" style=\"font-family:Verdana;\"> </span> 
</p>
<p class=\"MsoNormal\">
	<span lang=\"EN-US\" style=\"font-size:12px;\"> Background:</span><span lang=\"EN-US\"><span style=\"font-size:12px;\">The
mechanism concerning gingival overgrowth as a side effect of phenytoin, a
therapeutic drug for epilepsy has been still unclear. As one of mechanisms, by
measuring the intracellular calcium concentration (</span><span style=\"font-size:12px;\">[Ca</span><sup><span style=\"font-size:12px;\">2+</span></sup><span style=\"font-size:12px;\">]i)
of the gingival fibroblasts, it has been advocated that there is relationship
between gingival overgrowth and phenytoin-induced alterations in the [Ca</span><sup><span style=\"font-size:12px;\">2+</span></sup><span style=\"font-size:12px;\">]i
in gingival fibroblasts. To confirm that phenytoin elevates the [Ca</span><sup><span style=\"font-size:12px;\">2+</span></sup><span style=\"font-size:12px;\">]i,
and if so, to find out its mode of action.</span> <span style=\"font-size:12px;\">Methods:</span><span style=\"font-size:12px;\"> The [Ca</span><sup><span style=\"font-size:12px;\">2+</span></sup><span style=\"font-size:12px;\">]i was measured with the Ca</span><sup><span style=\"font-size:12px;\">2+</span></sup><span style=\"font-size:12px;\">-sensitive
fluorescent dye fura-2/AM. Cells were soaked in a flexiperm chamber and
perfused by a saline. Drugs at appropriate concentrations were added to the per</span></span><span lang=\"EN-US\"><span style=\"font-size:12px;\">fusate. </span><span style=\"font-size:12px;\">Results:</span> <span style=\"font-size:12px;\">Phenytoin concentration-dependently elevated the [Ca</span><sup><span style=\"font-size:12px;\">2+</span></sup><span style=\"font-size:12px;\">]i.
NPS</span><span style=\"letter-spacing:-0.1pt;font-size:12px;\">2390, a calcium-sensing receptor </span><span style=\"font-size:12px;\">(CaSR)
blocker, significantly suppressed the phenytoin-induced [Ca</span><sup><span style=\"font-size:12px;\">2+</span></sup><span style=\"font-size:12px;\">]i
elevation. U73122, a phospholipase C (PLC) inhibitor, inihibited the
phenytoin-induced [Ca</span><sup><span style=\"font-size:12px;\">2+</span></sup><span style=\"font-size:12px;\">]i elevation. TMB-8, a blocker of inositol
triphophate (IP</span><sub><span style=\"font-size:12px;\">3</span></sub><span style=\"font-size:12px;\">) receptors in ER, sig</span></span><span lang=\"EN-US\"><span style=\"font-size:12px;\">nificantly depressed the
phenytoin-induced [Ca</span><sup><span
%K Phenytoin
%K Calcium-Sensing Receptor
%K Endoplasmic Reticulum
%K Gingival Fibroblast
%K Gingival Overgrowth
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=30397