title: Combined effects of lutenizing hormone-releasing hormone analogue with antiestrogen on rat mammary tumors.
abstract: The efficacy of luteining hormone-releasing hormone (LH-RH) analogue, buserelin, combind with tamoxifen (TAM) on 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary tumors was investigated. Low-dose of TAM (L-TAM), 1 mg/kg daily, significantly suppressed the growth of tumors compared with no treatment group. High-dose of TAM (H-TAM), 10 mg/kg daily, suppressed growth considerably, and there was a significant difference in the antitumor effect between the L-TAM group and the H-TAM group. The combined treatment using buserelin and L-TAM significantly suppressed the tumor growth compared with the treatment using each single agent. LH-RH analogue actually reduced serum estradiol (E2) levels and enhanced the antitumor effect brought by a therapeutical dose of TAM. The reduction of serum cholesterol levels as a beneficial effect of TAM was reserved when combined with buserelin. Insulin-like growth factor 1 (IGF-1) expressions in tumors were significantly decreased in the buserelin and L-TAM group. These results support the usefulness of this combination in clinical use.
authors.affiliation: Second Department of Surgery, Gunma University Faculty of Medicine, Maebashi, Gunma 371-8511, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Yukio
authors.initials: Y
authors.lastname: Koibuchi
authors.forename: Jun
authors.initials: J
authors.lastname: Horiguchi
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Iino
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Morishita
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene / Q000009:adverse effects*; D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002064:Buserelin / Q000008:administration & dosage; D002784:Cholesterol / Q000097:blood; D004958:Estradiol / Q000097:blood; D005260:Female; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000188:drug therapy*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013629:Tamoxifen / Q000008:administration & dosage
chemical_list: D013629:Tamoxifen; D004958:Estradiol; D015127:9,10-Dimethyl-1,2-benzanthracene; D007334:Insulin-Like Growth Factor I; D002784:Cholesterol; D002064:Buserelin