Antitumor activity of bovine parotid hypocalcemic substance obtained by glacial acetic acid extraction
Mizutani, A.; Yamamoto, H.; Suzuki, I.
Gan 69(3): 291-297
1978
ISSN/ISBN: 0016-450X PMID: 556346 Document Number: 137165
The acetone-dried powder, obtained from the mother liquor left after separation of the pH 5.4-precipitating fraction (crude parotin) from the aqueous extract of a bovine parotid gland, was extracted with glacial acetic acid and its product was purified to a protein (MW 66,000) showing homogeneity in disc electrophoresis. Since this substance was expected to have antitumor activity, because of its action to increase the immune competence besides lowering serum Ca in rabbits, its effect on a solid tumor was examined with sarcoma 180 transplanted s.c. in Swiss-Webster or ICR-SLC mice. Four wk old mice were divided into 2 groups; 1 group was given the test solution and the other was injected with saline as a control. S.c. injection of 20 .mu.g/mouse (corresponding to about 1 mg/kg) of the purified product 1 wk before transplantation of sarcoma 180 in Swiss-Webster mice resulted in complete regression of the tumor in all of 8 mice, while s.c. injection of 1 .mu.g/mouse (corresponding to about 0.05 mg/kg) of the product every day for 10 days after transplantation also showed a tumor inhibition rate of 97.9%, the tumor disappearing in 5 of 6 mice. I.p. injection of 1 .mu.g/mouse of the product every day for 10 days after transplantation showed a tumor inhibition rate of 96.0%, the tumor disappearing in 3 of 6 mice. Examination of the thymus gland, liver, spleen and lymph nodes at the time of autopsy 35 days after transplantation of sarcoma 180 showed no special changes in these organs, except for greater swelling of the inguinal lymph node on the transplanted side when growth of the tumor was marked.