A highly spectrophotometric method for the determination of aluminum was developed. This method used the color reaction between m-carboxyphenylfluorone (MCPF) as a novel chemical probe and aluminum in the presence of a surfactant, poly(N-vinylpyrrolidone) (PVP, K-90) (0.03 -1.40 µg of aluminum in a final volume of 10 ml at 561 nm). The proposed method showed excellent sensitivity (molar absorptibity of 1.70 × 10 5 l mol -1 cm -1 ) and reproducibility (within-day precision: RSD = 0.35% n = 6, between-day precision: RSD = 0.44% n = 6). Linearity was achieved over the range 3 -140 µg L -1 with a correlation coefficient of 0.9999, and the effects of foreign substances were low.
Perinatal changes of the Brunner’s glands in rats from fetal day 20 through neonatal day 3 were studied morphometrically and electron-microscopically. Percentage volume of secretory granules of the gland cells did not change from fetal day 20 through neonatal day 1 and increased significantly from neonatal days 1-2; this level was maintained through neonatal day 3. Electron-microscopically, the gland cells during the fetal days were rich in free ribosomes. The Golgi apparatus and rough-surfaced endoplasmic reticulum (RER) were poorly developed during fetal days. After birth, however, the cells showed active formation of secretory granules, which was evidenced by well-developed Golgi apparatus, distended RER and accumulation of granules in the apical cytoplasm. Furthermore, light microscopy revealed that strongly PAS-positive material increased for the first time after birth, indicating remarkable formation of the secretory granules. Thus, the present study indicates that the cell of the Brunner’s glands become active in secretory granule formation just after birth by responding to ingested material following birth.
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