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)

In the relatively undifferentiated jejunal mucosa occurring in piglet viral enteritis, we measured the response of transepithelial Na+ and Cl- fluxes in vitro to raised intracellular adenosine 3',5'-cyclic monophosphate (cAMP) levels. At the acute 40-h stage of transmissible gastroenteritis (TGE), luminal membrane markers, sucrase and lactase, and a basolateral jejunal epithelial membrane marker Na+-K+-ATPase, were significantly decreased in activity, while a proliferative marker, thymidine kinase, was significantly enriched; these enzyme characteristics are typical of enterocytes isolated from crypts of other species. As expected, control piglet jejunum in short-circuited Ussing chambers after theophylline (10 mM) developed significant net secretory Na and Cl fluxes primarily due to significant antiabsorptive effects (delta JNa m----s = 3.48 +/- 0.52, delta JCl m----s = 2.59 +/- 0.28). Furosemide (10(-4) M), an inhibitor of electroneutral NaCl cotransport, produced antiabsorptive effects (delta JNa m----s = 2.53 +/- 0.31, delta JCl m----s = 2.58 +/- 0.28) in control jejunum that were not significantly different from those seen in response to theophylline. TGE jejunum, however, responded to theophylline not by an antiabsorptive effect but by significant electrogenic Cl- secretion (delta JCl s----m = 1.59 +/- 0.48); furosemide had no effect on ion fluxes in TGE tissue. Control and TGE jejunal mucosal homogenates did not differ in their basal or theophylline-stimulated levels of cAMP. We conclude that the relatively undifferentiated small intestine occurring in acute TGE does not generate either a cAMP-mediated antiabsorptive effect or a furosemide-mediated antiabsorptive effect.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Absence of a cAMP-mediated antiabsorptive effect in an undifferentiated jejunal epithelium. 303 40

To investigate the effect of chronic protein-calorie malnutrition on intestinal repair after an enteric infection, we examined small intestinal structure, enzyme activity, and sodium transport in undernourished piglets during the acute and convalescent phases of a viral enteritis, transmissible gastroenteritis (TGE). Gnotobiotic pigs, nutritionally deprived from the age of 7 days, gained less weight than dietary controls from 14 days of age until the end of the study. Animals from malnourished and control diet groups were inoculated with TGE virus at 22-23 days and studied during the acute (40 h) and convalescent (4, 10, and 15 days) stages of this experimental enteritis along with noninfected dietary controls. After TGE infection, we observed a further decrease in weight gain and an increased mortality only in undernourished pigs. In jejunum and ileum of both dietary groups at 40 h after TGE infection, we observed comparable structural lesions, similar decreased activities of mucosal enzymes (sucrase, lactase, sodium-potassium-dependent ATPase), and increased thymidine kinase activities. Also we noted comparable diminution of glucose-stimulated jejunal sodium absorption in both dietary groups at 40 h. In control diet pigs, transport abnormalities recovered by 4 days after TGE infection and normal mucosal structure and enzyme activity returned over 4-15 days. In undernourished piglets, structural repair and enzyme abnormalities were prolonged when compared with the control diet group; glucose-stimulated sodium transport did not recover until 10 days after infection and never regained the enhanced activity seen in noninfected undernourished controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Impact of chronic protein-calorie malnutrition on small intestinal repair after acute viral enteritis: a study in gnotobiotic piglets. 392 24