发育中大鼠结肠碳酸酐酶活性的定位

Lacy E R, Colony P C

Gastroenterology. 1985 Jul;89(1):138-50. doi: 10.1016/0016-5085(85)90754-1.

Carbonic anhydrase activity was localized histochemically by light and electron microscopy in the proximal and distal colon of developing rats. Fixed tissue was taken for normal morphology and carbonic anhydrase localization from fetal (20-22 days gestation), suckling (1-19 days postnatal), weanling (20-25 days postnatal), and adult rats. The proximal colon had distinct villi at birth which were diminished between days 5 and 11 postnatally. The distal colon lacked villi at birth but had rudimentary crypts (ridges and furrows) which were replaced during the suckling period by a flat mucosa interspersed with true crypts. Carbonic anhydrase first appeared in both proximal and distal colonic epithelial cells on the day of birth (22 days gestation). Goblet cells were nonreactive at each developmental period. In neonatal rats, epithelial cells in the upper half of the villi of the proximal colon and on the surface and upper crypts of the distal colon were positive for carbonic anhydrase throughout the cytoplasm. Cells at the villar base (proximal colon) or in the deep crypt (distal colon) had reaction product in the intercellular spaces but not the cytoplasm. By 11 days postnatal, cytoplasmic reaction product was present in proximal colonic cells in the upper three-fourths of the crypt and was concentrated in a heavy band in the apical cytoplasm. In the distal colon, cytoplasmic positive cells did not extend as deeply into the crypts and the apical banding pattern was weak. Intercellular spaces in the deeper crypt epithelium were positive in both proximal colon and distal colon, suggesting a membrane-bound carbonic anhydrase. It was concluded that carbonic anhydrase appeared suddenly at birth and was continuously present in mid- to upper-crypt (or upper villus in early neonatal proximal colon) non-goblet cells into adulthood. This suggests a functional role for carbonic anhydrase in chloride-bicarbonate exchange across the neonatal and adult colonic mucosa.

通过光镜和电镜组织化学方法，对发育中大鼠的近端和远端结肠碳酸酐酶活性进行了定位。从胎儿（妊娠20 - 22天）、哺乳（出生后1 - 19天）、断奶（出生后20 - 25天）和成年大鼠获取固定组织，用于正常形态学观察和碳酸酐酶定位。近端结肠在出生时具有明显的绒毛，在出生后第5至11天之间减少。远端结肠在出生时没有绒毛，但有原始隐窝（嵴和沟），在哺乳期被散布着真正隐窝的扁平黏膜所取代。碳酸酐酶在出生当天（妊娠22天）首次出现在近端和远端结肠上皮细胞中。杯状细胞在每个发育阶段均无反应。在新生大鼠中，近端结肠绒毛上半部分以及远端结肠表面和隐窝上部的上皮细胞在整个细胞质中碳酸酐酶呈阳性。绒毛基部（近端结肠）或深部隐窝（远端结肠）的细胞在细胞间隙中有反应产物，但细胞质中没有。到出生后11天，近端结肠隐窝上四分之三的细胞细胞质中有反应产物，并集中在顶端细胞质的一条粗带中。在远端结肠，细胞质阳性细胞没有深入到隐窝那么深，顶端带状模式较弱。近端结肠和远端结肠深部隐窝上皮的细胞间隙均为阳性，提示存在膜结合碳酸酐酶。结论是碳酸酐酶在出生时突然出现，并持续存在于隐窝中部至上部（或新生早期近端结肠的上部绒毛）的非杯状细胞中直至成年。这表明碳酸酐酶在新生儿和成年结肠黏膜的氯 - 碳酸氢根交换中起功能性作用。