Brown H H, Moon H W
Am J Vet Res. 1979 Nov;40(11):1573-7.
The localization and the specific activities of lysosomal enzymes in jejunal and ileal epithelium of suckling pigs were determined. Acid phosphatase was found in pinocytotic vesicles and vacoles at both intestinal sites in pigs examined during (less than or equal to 1 day old) or shortly after (2 days old) closure. These pinocytolically active vesicles and vacuoles were determined to be phagolysosomes. In the ileum, phagolysosomes persisted well after closure, at an age (10 days) when ileal epithelium retains the capacity for pinocytotic uptake of immunoglobulin, but does not transport it to blood. Neither jejunum nor ileum contained phagolysosomes at an age (30 days) when the intestine had lost both uptake and transport capacities. The specific activities of acid phosphatase and cathepsin B-1 in jejunum were similar for all age groups. However, the activities of these enzymes in ileum of 10-day-old pigs were three and five times greater than at any other age or site. The results are consistent with phagolysosomes in the ileum of 10-day-old pigs functioning as a "barrier" which prevents transport of the macromolecules which are taken up pinocytotically by this epithelium. The results do not permit conclusions whether (or not) the phagolysosomes which appear in jejunum and ileum of pigs less than or equal to 1 day old contribute to closure, because the transcellular route for immunoglobulin absorption in pigs has not been precisely defined.
测定了哺乳仔猪空肠和回肠上皮中溶酶体酶的定位和比活性。在小于或等于1日龄或关闭后不久（2日龄）检查的猪的两个肠道部位的胞饮小泡和液泡中发现了酸性磷酸酶。这些具有胞饮活性的小泡和液泡被确定为吞噬溶酶体。在回肠中，吞噬溶酶体在关闭后持续存在，在回肠上皮保留胞饮摄取免疫球蛋白但不将其转运到血液的年龄（10日龄）时仍存在。在肠道失去摄取和转运能力的年龄（30日龄）时，空肠和回肠均不含吞噬溶酶体。所有年龄组空肠中酸性磷酸酶和组织蛋白酶B-1的比活性相似。然而，10日龄猪回肠中这些酶的活性比其他任何年龄或部位高3至5倍。结果表明，10日龄猪回肠中的吞噬溶酶体起到“屏障”作用，阻止该上皮细胞通过胞饮摄取的大分子物质转运。由于猪中免疫球蛋白吸收的跨细胞途径尚未精确界定，因此无法得出小于或等于1日龄猪空肠和回肠中出现的吞噬溶酶体是否有助于关闭的结论。
