title: Microtubule-granule relationships in motile human polymorphonuclear leukocytes.
abstract: We examined the relationship of microtubules to the granule organization in stimulated human polymorphonuclear leukocytes (PMNs). Electron microscopic (EM) observations of critical-point-dried PMNs revealed that only a portion of the granules appeared in close association to microtubules. These closely associated granules appeared to be attached to the microtubule via smaller-diameter filaments. The remaining granules appeared either attached to microtubules at a further distance, via smaller-diameter filaments such as actin, or unassociated with microtubules. EM observations of PMNs treated with either the microtubule promoter drug taxol or the microtubule depolymerization drugs nocodozole and colchicine revealed a redistribution of granules towards the nucleus. Granule clustering at the periphery of the cell was also noted with nocodozole and colchicine. With cytochalasin B, a uniform distribution of granules was noted. However, granule clustering was noted when PMNs were coincubated with cytochalasin B and colchicine. These results indicate that microtubules may have both a direct and indirect role (through other cytoskeletal elements) in the organization of PMN granules.
mesh_terms: D000470:Alkaloids / Q000494:pharmacology; D001562:Benzimidazoles / Q000494:pharmacology; D003571:Cytochalasin B / Q000494:pharmacology; D006801:Humans; D002479:Inclusion Bodies / Q000187:drug effects / Q000648:ultrastructure*; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D008870:Microtubules / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000648:ultrastructure*; D015739:Nocodazole; D017239:Paclitaxel
chemical_list: D000470:Alkaloids; D001562:Benzimidazoles; D003571:Cytochalasin B; D009240:N-Formylmethionine Leucyl-Phenylalanine; D017239:Paclitaxel; D015739:Nocodazole