title: Inhibition of thymidine incorporation into epidermal and dermal DNA of HRS/J mice after a Colcemid pulse.
abstract: The introduction of a Colcemid pulse, which is known to inhibit microtubulin assembly and thereby influence cellular events dependent on the assembly, delayed the normal passage of G1 cells to S-phase. Experimental support for this hypothesis was obtained by the pulsing of cultured inbred HRS/J mouse skin for 30 minutes with 20 micrograms Colcemid/ml and by measurement of thymidine (dThd) incorporation for a 4-hour incubation period at different intervals after the pulse. Incorporation of dThd into epidermal and dermal DNA was maximally inhibited 9.5 and 17.5 hours after the Colcemid pulse. Maximal inhibition and minimal inhibition of dThd incorporation were observed 17.5 hours after different concentrations of Colcemid (1--30 micrograms/ml) were pulsed. Maximal inhibition of dThd incorporation occurred after pulsing with 20 micrograms Colcemid/ml. The acceleration of G0 or G1 events to S-phase in proliferative cells caused by mild epidermal stripping was also inhibited after the addition of the Colcemid pulse. The data suggest a time relationship between the Colcemid pulse, the subsequent disruption of microtubulin structure, and the inhibition of dThd incorporation into epidermal and dermal DNA. The intact microtubulin structure is apparently essential for the normal intracellular dependency among the cell membrane, the cytoskeleton structure, and the cell nucleus and occurs when the cells transit from G1 to S-phase.
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000187:drug effects; D004247:DNA / Q000096:biosynthesis*; D003703:Demecolcine / Q000494:pharmacology*; D004817:Epidermis / Q000187:drug effects; D005260:Female; D007399:Interphase / Q000187:drug effects; D051379:Mice; D008817:Mice, Mutant Strains; D012867:Skin / Q000187:drug effects* / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism*; D014404:Tubulin / Q000378:metabolism
chemical_list: D014404:Tubulin; D004247:DNA; D013936:Thymidine; D003703:Demecolcine