Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dental students (n = 31) with either high salivary lactobacillus count (greater than 10(4) CFU/ml) or high salivary sucrase activity (greater than or equal to 10 mumol/min X mg protein X 10(-3), or both, were selected to participate in this dietary experiment. For 2 weeks the students avoided sucrose in their diet. Stimulated saliva samples were collected before and after the diet. An additional follow-up sample was collected after 2 weeks of normal diet. The lactobacillus count of undiluted saliva was determined by the Dentocult dip-slide technique. The sucrase activity was determined spectrophotometrically by measuring the sucrose-cleaving activity of centrifuged saliva supernatant. Both the reduction in dietary sucrose and the return to normal diet caused a significant change in these values.
 ...
PMID:Effect of variations in sucrose consumption on salivary Lactobacillus count and sucrase activity in man. 347 34

We studied the postnatal development of bile acid transport in rat ileum, using brush border membrane vesicles prepared by a Ca2+ precipitation method. Membrane vesicles from developing (day 14-21) and adult Sprague-Dawley rats were enriched to a similar degree in brush border membrane marker enzyme activities (sucrase or lactase) compared with homogenate. Uptake of 25 microM [3H]taurocholate by adult membrane vesicles was markedly accelerated in the presence of an inwardly directed 100 mM Na+ gradient compared with a K+ gradient, and there was a transient intravesicular accumulation of isotope above equilibrium ("overshoot"). In contrast, at 14 and 16 days of age there was no difference in taurocholate uptake in the presence of a Na+ or a K+ gradient, and uptake was not saturable. The integrity of the vesicle preparation from 14- and 16-day-old rats was confirmed by the demonstration of Na+-dependent uphill transport of 100 microM L-[3H]alanine. Stimulation of taurocholate uptake by a Na+ compared with a K+ gradient ("sodium effect") was first observed at age 17 days, but an overshoot was not present until 18 days of age. The initial rate of Na+-dependent taurocholate (25 microM) uptake increased sixfold between 17 and 21 days of age (24.36 +/- 6.11 to 148.59 +/- 8.56 pmol X mg-1 protein X 5 s-1). Absent or decreased Na+-dependent taurocholate uptake was not due to increased permeability or "leakiness" of vesicles from younger animals to Na+. Ileal brush border membrane vesicles demonstrated saturable kinetics at 21 days, but the Vmax was significantly lower (10.15 +/- 0.44 vs. 13.42 +/- 0.59 nmol X mg-1 protein X min -1, p less than 0.001) and the apparent Km higher (130.6 +/- 18.9 vs. 70.1 +/- 12.6 microM, p less than 0.007) than the adult. We conclude that (a) saturable, Na+-bile acid coupled transport is absent in rat ileum throughout most of the suckling period and (b) kinetic analysis suggests that maturation occurs near weaning, primarily through an increase in functional bile acid carriers within the ileal brush border membrane.
 ...
PMID:Ontogeny of bile acid transport in brush border membrane vesicles from rat ileum. 395 37