Relation between inhibition of calmodulin and mediator release from rat mast cells

Effects of calmodulin antagonists on human adenoidal mast cells

“…Concentrations of 100 ~tM or higher released histamine by themselves in both species [4]. It could be shown that this histamine release is due to cytotoxic effects, since LDH liberation was reported to parallel the histamine release [5]. Our data show that W5 inhibited the Con A-induced histamine release about 4 times less potently than W7 and about 10 times less potently than TFPr.…”

“…Our data show that W5 inhibited the Con A-induced histamine release about 4 times less potently than W7 and about 10 times less potently than TFPr. The ICso of the calcium dependent phosphodiesterase (PDE) inhibition as an index for calmodulin antagonism was found to be 270 laM for W5, 38 laM for W7 [5] and 28 btM for TFPr [6]. Hence the ratios of concentrations for inhibition of PDE and histamine release are about equal.…”

Dual effect of dihydropyridines on 45Ca uptake induced by the K+ —channel blocker 4‐aminopyridin on mast cells

“…Nifedipine and related 1,4-dihydropyridines (DHP) exhibit potent and selective inhibitory actions on voltagesensitive calcium channels of the L-type (Spedding, 1987;Fleckenstein, 1985;Doyle, 1984). The purpose of our study was to investigate the effect of nifedipine (Bay A 10401, nisoldipine (Bay K 55521, and nitrendipine (Bay E 5009) on 45Ca uptake activated with 4-aminopyridin, a pharmacological agent which blocks K + channels (Ohishi et al, 1985). We found that 4-aminiopyridin activated 45Ca uptake in mast cells as did other Kf blockers such as quinine and sparteine (submitted data).…”

“…The purpose of our study was to investigate the effect of nifedipine (Bay A 10401, nisoldipine (Bay K 55521, and nitrendipine (Bay E 5009) on 45Ca uptake activated with 4-aminopyridin, a pharmacological agent which blocks K + channels (Ohishi et al, 1985). We found that 4-aminiopyridin activated 45Ca uptake in mast cells as did other Kf blockers such as quinine and sparteine (submitted data).…”

"Efeitos da melatonina sobre a produção de óxido nítrico em células endoteliais em cultura"

“…A maioria de suas ações é dependente de proteínas de ligação, que tem como função, intermediar o cálcio e a proteína a ser regulada, sendo a calmodulina, um dos exemplos mais marcantes. A interação cálcio-calmodulina participa na secreção de grânulos por mastócitos (Ohishi et al, 1985), ativação e migração de monócitos, macrófagos e neutrófilos (Singh e Sodhi, 1999;Hu et al, 2000), e na produção de NO por enzima constitutiva (Koyama et al, 2002).…”