Adrenalectomy Does Not Block the Inhibition of Mammary Carcinogenesis by Dietary Energy Restriction in Rats

摘要: Dietary energy restriction (DER) has been shown to reproducibly inhibit chemically induced mammary carcinogenesis. The inhibitory activity of DER reported be associated with an increase in circulating corticosterone as well a decrease insulin-like growth factor 1 (IGF-1). To determine whether the adrenal glands are required for cancer activity, effects were investigated adrenalectomized (ADX) rats. Female Sprague-Dawley rats, 29-31 per group, injected 0.05 g 1-methyl-1-nitrosourea/kg body wt at 21 d age, sham operated (SHAM) or bilaterally ADX 24 and after 3 adapted meal feeding during which rats ate ad libitum (AL) restricted 60% AL intake. resulted marked reduction serum both Whereas carcinogenic response gland was not statistically different SHAM-AL ADX-AL did block DER. In fact, greatest ADX-DER Circulating levels glucose, insulin, IGF-1, IGF binding protein also reduced Collectively, these findings indicate that manifestation If circulation-borne factors such IGF-1 involved inhibition carcinogenesis by DER, is likely play greater role than corticosterone.