PENGARUH BENZO (a) PIRENA DAN 7,12 - DINIETILBENZ (a) ANTRASENA TERHADAP TURBELLARIA

• Main Author: Mulyadi
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/2674
• Institution: Institut Teknologi Bandung

<b>ABSTRACT: </br></b> <br /> <p align=\"justify\">The aim of this work is to investigate the effects of benzo(a)pyrene (BP) and 7,12-dimethylbenz(a)anthracene (DMBA) on Turbellaria. It is known that Turbellaria belongs to the simplest Protostoma. These animals can be succesfully cultivated in our laboratory by using a suitable growth media at 25°C, while vigorous shaking must be avoided. In the course of further investigation it was found that BP as well as DMBA was not able to induce morphological changes in Turbellaria. On the other hand 7-hydroxymethyl 12-methylbenz(a)anthracene, which is known as an ultimate carcinogen, appeared to influence the morphology of the same experimental animals.<br /> <p align=\"justify\"> It is known that the latter substance can be formed from DMBA in animal tissues whereby cytochrome P-450 plays an important role. Further experiments revealed that this cytochrome was absent in Turbellaria, so this can explain why BP and DMBA were not active. Further it must be noted that the morphological defects disappeared within 11 days. This might be due to the fact that Turbellaria has a remarkable ability to regenerate itselves. This fact seems to be closely related to the existence of an efficient repair mechanism for DNA. However, in spite of the absence of cytochrome P-450, BP as well as DMBA was able to disturb protein and glycogen synthesis. Besides this a decrease in the specific as well as in the total activities of lactate dehydrogenase and glutamate pyruvate transaminase were observed.<p align=\"justify\">On the other hand, an increase in the specific and in the total activities of glutamate oxaloacetate transaminase, acid phosphatase, alkaline phosphatase, and rhodanese were detected. In these cases BP or DMBA might act not as an carcinogen but as an inducer or repressor in the synthesis of proteins including enzymes. Further it was found that Turbellaria homogenates, viz. the normal as well as the treated animals showed 8 protein bands on the disc gel electrophoregram. Two of them appeared to be isoenzymes of lactate dehydrogenase. These facts also indicate that BP as well as DMBA does not alter the DNA of the Turbellaria cells. The absence of cytochrome P-450 and the presence of an efficient repair mechanism in Turbellaria cause difficulties in inducing cancer in these animals. Whether this is a general rule for lower animals must be further examined extensively.