DIETARY, PHYLOGENETIC, AND ECOLOGICAL CORRELATES OF INTESTINAL SUCRASE AND MALTASE ACTIVITY IN BIRDS
DIETARY, PHYLOGENETIC, AND ECOLOGICAL CORRELATES OF INTESTINAL SUCRASE AND MALTASE ACTIVITY IN BIRDS
复制标题
DOI：
10.1086/physzool.63.5.30152625
复制
发表时间：
1990-09-01
期刊：
影响因子：
--
通讯作者：
DELRIO, CM
中科院分区：
文献类型：
--
作者：
DELRIO, CM
测量了来自墨西哥西部的 3 种蜂鸟和 11 种雀形目鸟类的肠道蔗糖酶和麦芽糖酶活性。蜂鸟按肠道标称面积标准化的最大蔗糖酶活性比九种表现出显着蔗糖酶活性的雀形目鸟类高 2-118 倍。两种雀形目动物（Turdus rufopalliatus 和 Catharus aurantiirostris）缺乏显着的蔗糖酶活性。据报道，仅限于三个密切相关的科（鹟科、鹟科和蜜科）的五种雀形目鸟类缺乏功能性蔗糖酶活性。蔗糖酶活性的种间变异可能受到摄食习惯和系统发育亲和力的影响。未发现蔗糖水解能力与体重之间存在异速生长关系。当从样品中删除两个不具有显着蔗糖酶活性的物种时，麦芽糖水解能力和体重呈异速相关（指数 = 0.65）。麦芽糖酶和蔗糖酶活性呈线性相关。蜂鸟和雀形目动物在麦芽糖酶和蔗糖酶活性之间的关系上有所不同。可以推测，这种差异是因为蜂鸟的蔗糖酶-异麦芽糖酶复合物的麦芽糖酶活性低于雀形目动物。不同物种间蔗糖酶的表观亲和力相差近 10 倍。这种变化可能并不反映“真实”亲和力（即溶液中蔗糖酶的亲和力）的差异，但可归因于蔗糖酶是膜结合酶而产生的未搅拌层效应。鸟类中蔗糖酶活性的存在或不存在可能会产生行为和生态后果。缺乏蔗糖酶活性的鸟类拒绝含有蔗糖的食物。鸟类传播的水果的果肉中不含蔗糖，部分原因是鸟类食果动物缺乏蔗糖酶活性。
Intestinal sucrase and maltase activities were measured in three species of hummingbirds and 11 species of passerine birds from western Mexico. Maximal sucrase activity standardized by nominal area of intestine was 2-118 times higher in hummingbirds than in the nine species of passerines that showed significant sucrase activity. Two species of passerines (Turdus rufopalliatus and Catharus aurantiirostris) lacked significant sucrase activity. Lack of functional sucrase activity has been reported in five species of passerine birds restricted to three closely related families (Muscicapidae, Sturnidae, and Mimidae). Interspecific variation in sucrase activity is probably influenced both by feeding habits and phylogenetic affinities. No allometric relation between sucrose hydrolysis capacity and body mass was found. When the two species with no significant sucrase activity were deleted from the sample, maltose hydrolytic capacity and body mass were allometrically related (exponent = 0.65). Maltase and sucrase activity were linearly correlated. Hummingbirds and passerines differed in the relationship between maltase and sucrase activities. It can be hypothesized that this difference is because the sucrase-isomaltase enzyme complex of hummingbirds has less maltase activity than that of passerines. The apparent affinity of sucrase varied almost 10-fold among species. This variation probably does not reflect differences in "real" affinity (i.e., the affinity of sucrase in solution) but can be attributed to unstirred-layer effects resulting from sucrase's being a membrane-bound enzyme. The presence or absence of sucrase activity in birds can have behavioral and ecological consequences. Birds lacking sucrase activity reject foods containing sucrose. The absence of sucrose in the pulp of bird-dispersed fruits can be partially explained by the lack of sucrase activity in bird frugivores.