Varma M, Chai J K, Meguid M M, Yang Z J
Neuroscience Program, Surgical Metabolism and Nutrition Laboratory, Department of Surgery, University Hospital, SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, USA.
Physiol Behav. 2001;74(1-2):29-35. doi: 10.1016/s0031-9384(01)00569-8.
Gender differences of feeding pattern in normal male and female rats are well recognized. Differences in gender-related feeding patterns have also been established following a variety of experimental manipulations, such as hypothalamic lesions, nicotine infusion, and total parenteral nutrition administration. Anorexia is a common feature during tumor growth. The present study examined whether the feeding indices constituting the feeding patterns differed with the development of cancer anorexia in male and female rats. Sixteen male and 15 female Fischer-344 rats had their food intake (FI) and feeding indices, meal number (MN) and meal size (MZ), continuously measured by a computerized rat eater meter. Viable methylcholanthrene (MCA) sarcoma cells (10(6)) were inoculated subcutaneously in 10 male (M-TB) and 8 female (F-TB) Fischer rats, while the rest were controls and received an equal volume of vehicle. Tumor-bearing (TB) rats became anorectic by Day 18, when the weight of the tumor was approximately 8% of the total body weight (BW). A notable decrease in BW was observed in both M-TB and F-TB. A decrease in FI resulted from different feeding indices between male and female rats. In male rats, lower FI was due to a decrease in both MN and MZ. In female rats, lower FI was solely due to a decrease in MN. The data show that gender differences in feeding patterns, which are an external manifestation of biochemical changes in the brain, occur following development of cancer-related anorexia suggesting that besides other factors, cancer anorexia is also influenced by sex-related hormones.
正常雄性和雌性大鼠进食模式的性别差异已得到充分认识。在进行各种实验操作后，如下丘脑损伤、尼古丁注入和全胃肠外营养给药，与性别相关的进食模式差异也已确立。厌食是肿瘤生长过程中的一个常见特征。本研究探讨了构成进食模式的进食指标在雄性和雌性大鼠癌症厌食症发展过程中是否存在差异。16只雄性和15只雌性Fischer-344大鼠的食物摄入量（FI）以及进食指标，即进食次数（MN）和餐量（MZ），通过计算机化大鼠进食测量仪进行连续测量。将10只雄性（M-TB）和8只雌性（F-TB）Fischer大鼠皮下接种10⁶个活的甲基胆蒽（MCA）肉瘤细胞，其余作为对照，接受等量的赋形剂。荷瘤（TB）大鼠在第18天时出现厌食，此时肿瘤重量约为总体重（BW）的8%。在M-TB和F-TB大鼠中均观察到体重显著下降。雄性和雌性大鼠进食指标不同导致了食物摄入量的下降。在雄性大鼠中，较低的食物摄入量是由于进食次数和餐量均减少。在雌性大鼠中，较低的食物摄入量仅归因于进食次数的减少。数据表明，进食模式的性别差异是大脑生化变化的外在表现，在癌症相关厌食症发展后出现，这表明除其他因素外，癌症厌食症也受性激素影响。
