Abstract |
Dual-parameter (DNA, RNA) flow cytometry (FCM) measurements were made on testicular and epidiymal sperm cells isolated from mice exposed by oral gavage to 0, 250, 500, or 1000 mg/kg x 5 d of the fungicide methylbezimidazol-2-yl carbamate (MBC), which is known to bind with tubulin subunits and inhibit polymerization and microtubule formation. Effects of exposure to MBC were measured at 7, 24, and 39 d posttreatment. MBC had no effect on body weights, but testis weights and sperm parameters were altered, with few exceptions, only at the highest exposure level. Testis weights were reduced by about 25% at 7 and 24 d after exposure; recovery was observed by 39 d after treatment. FCM measurements of testicular cells showed relative percentages of certain testicular populations (round, elongating, and elongated spermatids) were different from the control pattern 7 and 24 d after treatment. These data demonstrate that spermatogenesis is sensitive to high-dose MBC exposure resulting in an altered ratio of testicular cell types present, abnormal sperm head morphology, and an altered sperm chromatin structure. (Copyright (c) 1987 by Hemisphere Publishing Corporation.) |