Genton Laurence, Reese Shannon R, Ikeda Shigeo, Le Tho C, Kudsk Kenneth A
Department of Surgery, University of Wisconsin Medical School, Madison, Wisconsin 53792-7375, USA.
JPEN J Parenter Enteral Nutr. 2004 Nov-Dec;28(6):431-4. doi: 10.1177/0148607104028006431.
Bombesin, the amphibian analog of mammalian gastrin-releasing peptide, reverses total parenteral nutrition (TPN)-induced atrophy of gut-associated lymphoid tissue and increases intestinal and respiratory immunoglobulin A (IgA) levels. Structure-activity studies suggested that the biologically active portion of bombesin is a C-terminal heptapeptide (7AA). This study investigates the effect of 7AA on lymphocytes counts of the Peyer's patches (PP), the lamina propria (LP) and the intraepithelial layer (IE).
Forty-eight male mice were randomized to receive chow (n = 13), TPN only (n = 9), TPN + 15 microg 7AA 3 times per day (n = 13) or TPN + 150 microg 7AA 3 times per day (n = 13). After 5 days of feeding, PP, LP, and IE lymphocytes were determined. Intestinal IgA levels were measured with ELISA. Groups were compared with ANOVA.
All TPN-fed mice lost more weight than mice fed chow (p < .04). Lymphocyte counts in PP, LP, and IE were significantly lower in the TPN group than in the 3 other groups but did not differ between the groups fed chow, TPN + 15 microg 7AA 3 times per day, or TPN + 150 microg 7AA 3 times per day. Intestinal IgA levels were higher in chow-fed mice (148.4 +/- 16.9) than in mice fed TPN (98.4 +/- 14.0, p = .008), TPN + 15 microg 7AA 3 times per day (96.9 +/- 7.7, p = .003) or TPN + 150 microg 7AA 3 times per day (87.3 +/- 6.7, p = .001).
The C-terminal heptapeptide of bombesin prevented the TPN-induced decrease in intestinal lymphocyte populations but not the reduction in intestinal IgA levels.
蛙皮素是哺乳动物胃泌素释放肽的两栖类类似物，可逆转全肠外营养（TPN）诱导的肠相关淋巴组织萎缩，并提高肠道和呼吸道免疫球蛋白A（IgA）水平。结构-活性研究表明，蛙皮素的生物活性部分是C端七肽（7AA）。本研究调查了7AA对派尔集合淋巴结（PP）、固有层（LP）和上皮内层（IE）淋巴细胞计数的影响。
48只雄性小鼠随机分为4组，分别给予普通饲料（n = 13）、仅接受TPN（n = 9）、TPN + 15微克7AA每日3次（n = 13）或TPN + 150微克7AA每日3次（n = 13）。喂养5天后，测定PP、LP和IE淋巴细胞数量。用酶联免疫吸附测定法测量肠道IgA水平。采用方差分析对各组进行比较。
所有接受TPN喂养的小鼠体重减轻均多于喂食普通饲料的小鼠（p < 0.04）。TPN组PP、LP和IE中的淋巴细胞计数显著低于其他3组，但喂食普通饲料组、TPN + 15微克7AA每日3次组或TPN + 150微克7AA每日3次组之间无差异。喂食普通饲料的小鼠肠道IgA水平（148.4±16.9）高于接受TPN喂养的小鼠（98.4±14.0，p = 0.008）、TPN + 15微克7AA每日3次组（96.9±7.7，p = 0.003）或TPN + 150微克7AA每日3次组（87.3±6.7，p = 0.001）。
蛙皮素的C端七肽可防止TPN诱导的肠道淋巴细胞数量减少，但不能防止肠道IgA水平降低。
