Mante S D, Flashner M, Tanenbaum S W
Cytobiologie. 1978 Jun;17(1):10-22.
Cytochalasin A (CA) at 1.6 X 10(-5)M and lower concentrations produced disruptive effects upon plasmodia, sclerotia, and spherule forms of Physarum polycephalum. CA effects upon either micro- or macroplasmodia included: cytoplasmic condensation, plasmodial contraction, and scission at the plasma membrane. The latter manifestation was most dramatically observed by scanning electron microscopy. Electron microscopy of drug-treated palsmodia confirmed the above phase contrast light-microscopic results and revealed, in addition, vacuolar enlargement, decreased membrane invaginations, and the presence of condensed particles within the plasmodium and at the plasma membrane. These results of drug action were not reversed by washing of exposed plasmodia. Germination of the slcerotial and spherule forms of Physarum was CA-delayed by 12 and 96 hours, respectively. Approximately 10% of drug-treated sclerotia were found to have been burst apart. These dramatic CA effects were nullified by preincubation of the drug either with L-cysteine or with beta-mercaptoethanol; however, iodoacetamide (10(-6)M) gave no such morphologic consequences. Cytochalasins B or D at comparable concentrations were without activity. It is concluded therefore that CA effects upon the myoxomycete reflect specific acceptor responses.
1.6×10⁻⁵M及更低浓度的细胞松弛素A（CA）对多头绒泡菌的原质团、菌核和小球体形式产生破坏作用。CA对微原质团或大原质团的作用包括：细胞质浓缩、原质团收缩以及质膜处的断裂。通过扫描电子显微镜最能显著观察到后一种表现。对经药物处理的原质团进行电子显微镜观察证实了上述相差光学显微镜的结果，此外还显示液泡增大、膜内陷减少以及在原质团内和质膜处存在凝聚颗粒。这些药物作用的结果不会因洗涤暴露的原质团而逆转。多头绒泡菌菌核和小球体形式的萌发分别被CA延迟了12小时和96小时。发现约10%经药物处理的菌核已经破裂。预先将药物与L - 半胱氨酸或β - 巯基乙醇一起孵育可消除这些显著的CA效应；然而，碘乙酰胺（10⁻⁶M）不会产生此类形态学后果。浓度相当的细胞松弛素B或D没有活性。因此得出结论，CA对黏菌的作用反映了特定的受体反应。
