Cysteinyl Leukotrienes Mediate Histamine Hypersensitivity Ex Vivo by Increasing Histamine Receptor Numbers

Table 1 Effects of leukotriene E ₄ on number of histamine H ₁ receptors in human peripheral blood monocytes

Volunteer	Receptors/cell before stimulation	Receptors/cell after stimulation	K _d (nM)
A	54207	105403	6
B	45173	90345	6
C	22586	48184	5.5
D	12046	57219	6.7
E	2259	9787	3

Blood was isolated from five healthy volunteers (A–E) and monocytes were prepared. These cells were stimulated with leukotriene E₄ (100 ng/ml) for 15 min. Scatchard analysis was performed to determine number of receptors per cell as described in Materials and Methods.

ISSN: 1528-3658