Use of transmission electron microscope to assess the damage to Sarcoma 180 ascites tumour cells following in vivo treatment of mitomycin-C and gamma radiation

Five day old Sarcoma 180 tumour bearing mice were exposed to different doses of mitomycin-C (4 mg or 7 mg per kg body weight of mouse) and gamma radiation (400 R or 800 R) applied singly or in combination. Surviving populations were collected after 5 days of treatment and processed for transmission electron microscopy. The control Sarcoma 180 tumour cells has the following characteristics: profused microvilli, different sized mitochondria with poorly developed internal structure, distinct endoplasmic reticulum studded with ribosomes, the large nucleus rich in chromatin materials and distinct nucleolus containing closely interwined granular and fibrillar components with associated chromatins. Damage to treated cells were ascertained by the reduction in microvilli, swelling of mitochondria with cloudy appearance, dilation and fragmentation of endoplasmic reticulum, blebbing of nuclear membrane, condensation of heterochromatin, appearance of perichromatin granules, segregation and fragmentation of nucleolus and invagination of plasma memebrane with increased intracellular spaces. With the help of transmission electron microscope it is thus possible to assess the nature of damage to organelles effected by mitomycinC and radiation both singly and in combination. Growth inhibition and damage in the cellular ultrastructure were maximum among tumour cells which survived with concomitant treatment with 7 mg MMC and 800 R. (author). 7 refs., 4 figs., 1 tab