Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.108 (lactase)
 2,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Activities of maltase, sucrase, lactase and acid-beta-galactosidase were studied in jejunum and ileum of term rat fetuses obtained by cesarian section. Female rats were either untreated or injected daily in the last (3rd) week of pregnancy with cortisone acetate (10 or 50 mg/100 g body weight) or L-triiodothyronine (20 or 50 microgram/100 g body weight). Two other control groups were injected with appropriate solvents. Cortisone or T3 treatment to mothers increased sucrase and maltase activity in jejunum and ileum of the offspring. Generally, higher doses of hormone were more effective. Lactase activity was increased by 25% in the jejunum by the higher dose of cortisone. Both doses of cortisone increased ileal lactase. Jejunal acid-beta-galactosidase activity was decreased in fetuses of T3-treated mothers.
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PMID:Effect of cortisone or L-triiodothyronine administration to pregnant rats on the activity of fetal intestinal disaccharidases and lysosomal acid beta-galactosidase. 41 95

Glucocorticoids and thyroxine modulate postnatal intestinal sucrase and lactase activities. Whether changes in enzyme activity are accompanied by changes in enzyme mRNA levels were determined in day 6 rats given thyroxine, cortisone, or thyroxine plus cortisone and killed 3 days later. Cortisone induced precocious expression of jejunal sucrase activity which was enhanced when cortisone plus thyroxine was administered; sucrase mRNA changed in parallel. Jejunal lactase activity was unaffected by thyroxine and was increased after cortisone, but not after thyroxine plus cortisone. Jejunal lactase mRNA levels increased equally after cortisone or after cortisone plus thyroxine. Thus, cortisone induces coordinated increases in sucrase and lactase activities and in corresponding mRNA levels. Thyroxine only enhances cortisone induced sucrase expression and antagonizes cortisone by depressing lactase activity post-translationally.
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PMID:Cortisone and thyroxine modulate intestinal lactase and sucrase mRNA levels and activities in the suckling rat. 171 74

Interactions of cortisone and thyroxine (T4) in modulating jejunal sucrase and lactase expression were studied in rats during early postnatal life. Cortisone (50 micrograms/g body wt) precociously induced sucrase activity in days 5-16 rats and enhanced activity thereafter until day 22. T4 (1 microgram/g) plus cortisone evoked greater sucrase expression in day 9 or younger rats. T4 did not induce sucrase expression until day 13. Lactase activity was enhanced in rats younger than day 9 by cortisone, and this effect was abolished when T4 was added. In days 19 and 22 rats, cortisone depressed lactase; with T4, lactase activity was further decreased. T4 alone did not suppress lactase activity until day 19. Quantitation of jejunal enzyme content showed that sucrase catalytic activity was higher in day 22 than 19 or younger rats and lower in rats given T4 than cortisone. In contrast, lactase activity remained constant in all animal groups. In vivo [35S]methionine-labeling studies using day 9 rats showed that cortisone induced de novo synthesis of sucrase and increased 35S incorporation into lactase. Cortisone plus T4 increased 35S incorporation into sucrase further and significantly increased 35S incorporation into lactase. We conclude that 1) cortisone and T4 cooperatively stimulate sucrase expression and reduce lactase activity during early postnatal life and 2) reduction in lactase activity accompanied by increase in lactase synthesis suggests that cortisone and T4 regulate lactase activity at posttranslational level.
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PMID:Thyroxine and cortisone cooperate to modulate postnatal intestinal enzyme differentiation in the rat. 190 Jun 72

Cortisone- and/or thyroxine (T4)-induced changes in jejunal lactase activity and epithelial cell migration were studied to determine the relationship of these two events. In suckling rats given a single dose of cortisone on day 6, jejunal lactase activity increased by 37% and cell turnover rate by 95% 3 days later, whereas T4 alone induced no changes. After cortisone plus T4, jejunal lactase activity decreased by 23% while cell turnover rate increased by 176%. Among all animal groups, the patterns of lactase expression along the crypt-villus (C-V) axis were similar, being low at the C-V junction, increasing to a high plateau at the mid- or third quarter villus level, and decreasing slightly at the villus tip. The calculated epithelial cell age at half maximum lactase expression in cortisone-treated and cortisone plus T4-treated rats was 30 and 53% younger than in control rats. Maximum lactase activity in villus cells was approximately 45% higher in cortisone-treated than in control or cortisone plus T4-treated rats. Parallel measurements of sucrase and lactase activities along C-V axis showed elevated lactase activity at higher villus positions than lead sucrase activity, suggesting that cortisone action occurs in villus cells. Thus jejunal lactase expression may be modulated by 1) adjusting villus cell age required for maximum expression, 2) altering the level of lactase activity in villus cells, and 3) changing the turnover rate of lactase containing epithelial cells.
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PMID:Intestinal lactase expression and epithelial cell transit in hormone-treated suckling rats. 190 Jun 73

Imposition of undernutrition during the suckling period considerably enhanced the intestinal uptake of D-glucose and glycine compared to a control group. Brush border sucrase, and alkaline phosphatase activities were drastically reduced while lactase and leucine amino peptidase levels were significantly elevated at weaning in nutritionally deprived pups as compared to control animals. Cortisone administration to undernourished rats depressed the uptake of D-glucose but stimulated that of glycine. Thyroxine treatment to undernourished animals reduced the uptake of glucose but had no effect on glycine absorption. Brush border sucrase and alkaline phosphatase activities were stimulated in cortisone- or thyroxine-injected undernourished rats but lactase activity was depressed under these conditions. Leucine aminopeptidase activity remained unaffected in cortisone- or thyroxine-administered undernourished pups.
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PMID:Alterations in intestinal function in response to thyroxine and cortisone administration in undernourished rats. 713 57

Lactase exists in both soluble and membrane-bound forms in suckling rat intestine. The distribution of lactase and its glycosylated isoforms in response to thyroxine or cortisone administration has been studied in suckling rats. 75% of lactase activity was detected, associated with brush borders, compared to 24% in the soluble fraction of 8-day-old rats. Thyroxine treatment enhanced soluble lactase activity to 34%, whereas particulate fraction was reduced to 67% compared to controls. Cortisone administration reduced soluble lactase activity from 24% in controls to 12% with a concomitant increase in membrane-bound activity to 89%. Western blot analysis revealed lactase signal, corresponding to 220 kDa in both the soluble and membrane fractions, which corroborated the enzyme activity data. The elution pattern of papain solubilized lactase from agarose-Wheat Germ agglutinin, or Concanavalin A or Jacalin agglutinin columns was different in the suckling and adult rat intestines. Also the elution profile of lactase activity from agarose-lectin columns was modulated in cortisone, thyroxine, and insulin injected pups, which suggests differences in glycosylated isoforms of lactase under these conditions. These findings suggest the role of these hormones in inducing changes in lactase glycosylation during postnatal development of intestine, which may contribute to adult-type hypolactasia in rats.
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PMID:Hormone induced changes in lactase glycosylation in developing rat intestine. 1871 86