Effect of 7,12-dimethylbenz[a]anthracene-induced mammary carcinogenesis on the opioid peptide levels in the rat central nervous system.
Mammary tumors were induced in female Sprague-Dawley rats by giving a single oral dose of 20 mg 7,12-dimethylbenz[a]anthracene (DMBA). Animals were killed after full development of tumors 4 months after the ingestion of DMBA. Opioid peptides in various tissues were estimated by radioimmunoassay (RIA). Tumor-bearing rats (n = 5) had higher (P less than 0.05) contents of beta-endorphin in pituitary (+60%), striatum (+52%) and midbrain (+85%) compared to animals with no tumors. However, tumor-bearing rats showed a decrease of 35% in striatal met-enkephalin content. Dynorphin level decreased (P less than 0.05) in pituitary (-49%) and hypothalamus (-29%) of tumor-bearing rats. Thus for the first time, we report the alteration in the level of these neuropeptides during the process of chemical carcinogenesis.
Vaswani
K K
KK
Tejwani
G A
GA
Abou-Issa
H M
HM
D015127:9,10-Dimethyl-1,2-benzanthracene; D000311:Adrenal Glands / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism*; D003342:Corpus Striatum / Q000378:metabolism; D004399:Dynorphins / Q000378:metabolism; D004723:Endorphins / Q000378:metabolism*; D004744:Enkephalin, Methionine / Q000378:metabolism; D005260:Female; D007031:Hypothalamus / Q000378:metabolism; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism; D010902:Pituitary Gland / Q000378:metabolism*; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D001615:beta-Endorphin
D004723:Endorphins; D010446:Peptide Fragments; D015127:9,10-Dimethyl-1,2-benzanthracene; D004744:Enkephalin, Methionine; D001615:beta-Endorphin; C026843:dynorphin (1-13); D004399:Dynorphins