![Fig. 8. Binding to and intracellular Ca++-mobilizing activity of IL-8(1-77) and IL-8(7-77) in neutrophils. / (A) Relative binding properties of IL-8(1-77) and IL-8(7-77) to human neutrophils were compared. Neutrophils were incubated with125I–IL-8(6-77) and various concentrations of unlabeled IL-8(1-77) and IL-8(7-77). The decrease in cell-bound radioactivity was used as a measure for competition by the unlabeled IL-8 forms and thus for their affinity to the cells. Mean and SEM (n = 4) are indicated. (B) Intracellular Ca++-mobilizing activities of IL-8(1-77) and IL-8(7-77) were determined by measurement of the fluorescence of the dye fura-2 during stimulation with the IL-8 forms. One representative experiment of 2 is shown. Successive one-third dilutions of both IL-8 forms were analyzed until no increase of [Ca++]i could be measured. The detection limit in [Ca++]i increase was 15 nmol/L. Stimulation with IL-8(1-77) at 0.17 nmol/L and IL-8(7-77) at 0.006 nmol/L resulted in a [Ca++]i increase below the detection limit.](https://ash.silverchair-cdn.com/ash/content_public/journal/blood/96/8/10.1182_blood.v96.8.2673/5/h82000242008.jpeg?Expires=1735684636&Signature=D~HfsKjk3OvyZ2u3dgMRa5At1dfZUcekLvHkIst0ko7eByIucTmoBovre91x-4pVm-0DwfaeLTiSEuXFkLIi6XDhxH96XRVZzEy6zcHwsP0emA0hSZR6Ee3R2a3uF3h6PgIzqgLehxdeNvQURL9G9P0l9THRdJayfk5VWdBfds9S3ttdJMN9SHJjcxcJiOKDVvc7suscep-VbWMsNk4i7~cD4u7yqA1hAKojmk8gJvbBvqTpmwWI9CMSv44HyZV7Nm7SGApD~HezTEKVHhp6t769JhcdLmwrQlPt~USnMA6K-1UbgeKXbAtH~JIASZY9rvmQxps7l8mqCawHiNQIxQ__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
Binding to and intracellular Ca++-mobilizing activity of IL-8(1-77) and IL-8(7-77) in neutrophils.
(A) Relative binding properties of IL-8(1-77) and IL-8(7-77) to human neutrophils were compared. Neutrophils were incubated with125I–IL-8(6-77) and various concentrations of unlabeled IL-8(1-77) and IL-8(7-77). The decrease in cell-bound radioactivity was used as a measure for competition by the unlabeled IL-8 forms and thus for their affinity to the cells. Mean and SEM (n = 4) are indicated. (B) Intracellular Ca++-mobilizing activities of IL-8(1-77) and IL-8(7-77) were determined by measurement of the fluorescence of the dye fura-2 during stimulation with the IL-8 forms. One representative experiment of 2 is shown. Successive one-third dilutions of both IL-8 forms were analyzed until no increase of [Ca++]i could be measured. The detection limit in [Ca++]i increase was 15 nmol/L. Stimulation with IL-8(1-77) at 0.17 nmol/L and IL-8(7-77) at 0.006 nmol/L resulted in a [Ca++]i increase below the detection limit.
