Analysis of the leukotriene D4 receptor in the granulation tissue of allergic inflammation in rats.
Leukotriene (LT) D4 receptor in the granulation tissue formed in the air pouch-type allergic inflammation model in rats was analyzed. Membrane preparation of the granulation tissue obtained 3-9 days after the antigen challenge has specific binding sites of [3H]LTD4. Scatchard analysis showed that the affinity (Kd) and the density (Bmax) were not changed among the granulation tissue obtained 3-9 days after the antigen challenge. The Kd value in the granulation tissue (0.90 +/- 0.12 nM) was close to that in the rat lung (1.00 +/- 0.24 nM) and the guinea pig lung (0.86 nM). On the other hand, Bmax (62 +/- 8 fmol/mg protein) in the granulation tissue was higher than that in the rat lung (21 +/- 4 fmol/mg protein) but was far less than that in the guinea pig lung (405 fmol/mg protein). LTC4 and LTE4 inhibited the binding of [3H]LTD4 to the membrane preparation of the granulation tissue in a concentration-dependent manner. IC50 of LTC4 and LTE4 were 1 x 10(-7) and 2 x 10(-7) M, respectively. A guanine nucleotide, guanyl-5'-yl-imido-diphosphate (GppNHp), reduced [3H]LTD4 binding to the membrane preparation of the granulation tissue suggesting that LTD4 receptors in the granulation tissue are associated with G proteins. These results indicate that LTD4 binding sites in the granulation tissue are high affinity receptors for LTD4. A possible role of LTD4 in the recurrence of allergic inflammation in the chronic phase is discussed.
Hirasawa
N
N
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tohoku University, Miyagi, Japan.
Hoshi
T
T
Kudoh
M
M
Mue
S
S
Tsurufuji
S
S
Watanabe
M
M
Ohuchi
K
K
D000818:Animals; D001249:Asthma / Q000276:immunology; D016535:Bronchial Hyperreactivity / Q000276:immunology*; D001991:Bronchitis / Q000139:chemically induced / Q000276:immunology*; D002462:Cell Membrane / Q000378:metabolism; D004195:Disease Models, Animal; D019204:GTP-Binding Proteins / Q000378:metabolism; D006097:Granulation Tissue / Q000276:immunology*; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D017999:Leukotriene E4; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011971:Receptors, Immunologic / Q000378:metabolism*; D018077:Receptors, Leukotriene; D013189:SRS-A / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D013047:Specific Pathogen-Free Organisms
D011971:Receptors, Immunologic; D018077:Receptors, Leukotriene; D013189:SRS-A; D006165:Guanylyl Imidodiphosphate; D017999:Leukotriene E4; D019204:GTP-Binding Proteins