Date of Award


Degree Type


University or Center

Atlanta University (AU)

Degree Name




First Advisor

Dr. Roy Hunter, Jr.


The purpose of this investigation has been to define in histological and histochemical terms the in. vitro effects of beryllium nitrate on tail tissue of Rana pipiens larvae. Sections of tadpole tissue were cultured in Niu-Twitty medium containing varying concentrations of beryllium for 4, 12 and 24 hr. Additional sections of tissue were exposed to beryllium in varying concentrations for 10 and 60 sec, and cultured in beryllium-free Niu-Twitty solution for 12 and 24 hr.

Histological observations revealed that beryllium did not cause any excessive tissue destruction in culture, as had been observed in regeneration experiments. However, connective tissue elements were abnormally affected by beryllium ions in culture. Histochemical observations, based on the staining potential of DNA and RNA in the peripheral notochordal cells, revealed that beryllium, in increasing concentrations, decreased the staining potential of DNA and RNA. Further investigation of muscle tissue, connective tissue and the lamellae surrounding the notochord showed a quantitative decrease in their protein content, which was indicated by a decrease in the staining intensity (using bromphenol blue) of these tissues when compared to control sections.

It was concluded that beryllium abnormally affected DNA, RNA and proteins. However, it was noted that the wide range of beryllium-caused destruction could not be totally visualized on the cellular level, but encompassed some effects on the tissue level.

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