ACTIVATION OF CARBONIC ANHYDRASE IS INVOLVED IN THE CHEMOPREVENTIVE AND ANTITUMOR EFFECTS OF C VITAMIN
In the last few years some studies have pointed out the prophilactic and therapeutic effects of C vitamin in certains forms of cancer. Other 959f51j studies show that erythrocyte carbonic anhydrase (CA) II activity is significantly reduced in all types of cancer, as compared to controls or to patients having diseases other than cancer.
AIM
To follow the effects of some cancerigenic substances alone and associated to C vitamin on CA activity in animals to clarify possible involvement of CA in carcinogenesis.
MATERIAL AND METHOD
In vivo: we constituted 4 groups of 20 rats each. They were treated for 10 days by gavage as follows: Gr.1 / C vitamin 1g/day.;Gr.2/ benzpyrene, 200 ppm/day;Gr.3/ C vitamin, 1g/day + benzpyrene 200 ppm/day; Gr.4/control group. Red cell CA I and CA II and gastric mucosa CA IV activity was determined by stopped-flow method using a rapid kinetic apparatus (HI-TECH, England). Differentiation between erythrocyte CA I and CA II activity was achieved by the test with nicotinates and CA IV by the Maren's method.
RESULTS
Group |
Erythrocyte CA I |
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Gastric CA IV |
Control | |||
C Vitamin |
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Benzpyrene | |||
C Vitamin + Benzpyrene |
CONCLUSIONS
The role of alkalin intracellular pH (pHi) in favouring carcinogenesis has been demonstrated along with processes attenuation due to acid pHi. Benzpyrene-induced inhibition of CA with rising of pHi could be involved in carcinogenesis. CA activation by C vitamin and antagonization of the inhibitory effect of benzpyrene on CA with a decrease of pHi could explain the favourable effect of C vitamin in some forms of cancer.
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