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I Idoate

Publications and source records attributed to I Idoate.

10 recordsLinked to original sources
PubMed1998

Drug-nutrient interactions: inhibition of amino acid intestinal absorption by fluoxetine.

Fluoxetine is one of the most widely used antidepressants and nowadays it is also being used to manage obesity problems. In our laboratory we demonstrated that the drug inhibited sugar absorption (Monteiro et al. 1993). The aim of the present work was to determine the effect of fluoxetine on intestinal leucine absorption. Using a procedure of successive absorptions in vivo the drug diminished amino acid absorption by 30% (P < 0.001). Experiments in vitro in isolated jejunum also revealed a reduction in leucine uptake of 37% (P < 0.001). In both cases fluoxetine only affected mediated transport without altering diffusion. In a preparation enriched in basolateral membrane, fluoxetine inhibited the Na+,K(+)-ATPase (EC 3.6.1.37) activity (55%; P < 0.001) in a non-competitive manner with an inhibition constant (Ki) value of 0.92 mM. Leucine uptake by brush-border membrane vesicles was diminished by the drug (a reduction of 48% was observed at 30s, P < 0.001); only the apical Na(+)-dependent transport system of the amino acid was modified and the inhibition was non-competitive. Leucine uptake in the presence of lysine indicated that transporter B was involved. These results suggest that fluoxetine reduces leucine absorption by its action on the basolateral and apical membrane of the enterocyte; the nutritional status of the patients under drug treatment may be affected as neutral amino acid absorption is decreased.

Animals↗
PubMed1996

Interactions of cephradine and cefaclor with the intestinal absorption of D-galactose.

Oral cephalosporins are frequently prescribed beta-lactam antibiotics. Although it has been well established that cephalosporins compete with dipeptides for absorption in the intestine, using the same transport mechanism, little is known about the action of the drugs on the absorption of other nutrients. In this work the effect of cephradine and cefaclor on the absorption of D-galactose has been studied. Intestinal sugar uptake was measured in-vitro in pieces of intestine (50 mg) and brush-border membrane vesicles, and in-vivo in intestinal loops. Galactose uptake was inhibited by cephalosporins in a dose-related, time-dependent manner. In-vivo the inhibition appeared when the antibiotics were on the luminal side of the enterocyte and when they reached the gut from the basolateral side. Only the active transport of the sugar was modified; passive transfer did not change in the presence of cephalosporins. In brush-border membrane vesicles, cephradine and cefaclor did not alter sugar uptake in either sodium or potassium gradients. Both antibiotics non-competitively inhibited basolateral Na+,K(+)-ATPase activity. These findings show that cephradine and cefaclor inhibit the active-transport component of galactose absorption because they reduce the activity of the basolateral Na+,K(+)-ATPase.

Animals↗
PubMed1996

Influence of cephalosporins on intestinal enzymatic activity.

The effect of the broad spectrum antibiotics cefaclor, cefadroxil, cephradine, cefatrizine, cephaloglycine and cefroxadine was examined on rat intestinal brush border enzymes, aminopeptidase N (E.C. 3.4.11-2), dipeptidyl peptidase IV (E.C. 3.4.14.5) and alkaline phosphatase (E.C. 1.3.1.3.). All the cephalosporins assayed -except cefaclor- inhibit the aminopeptidase N activity, in an uncompetitive manner. Cefatrizine showed the most important inhibitory effect (52.5%; p < 0.001). Cefaclor and cefadroxil have no effect on the activity of the dipeptidyl peptidase IV, while cephaloglycine and cephradine showed a non competitive type inhibition. In contrast, cefatrizine and cefroxadine showed a competitive inhibition for this enzyme. None of the cephalosporins assayed had any effect on alkaline phosphatase activity.

Administration, Oral↗
PubMed1991

Effects of cefroxadine on L-leucine absorption in rat jejunum.

The effect of cefroxadine, an aminocephalosporin (beta lactam antibiotic) on rat intestinal L-leucine transport has been studied. Cefroxadine inhibited the L-leucine uptake by the intestinal mucosa in a dose-dependent fashion. In vivo studies showed that cefroxadine reduced L-leucine absorption. This effect was irreversible. Only the active transport component of the absorption was inhibited. Oxygen consumption of the mucosa was reduced by cefroxadine which inhibited the activity of the basolateral (Na(+)-K+) ATPase also.

Animals↗
PubMed1990

Effect of cefatrizine and cephaloglycine on L-leucine absorption in rat jejunum.

1. The oral cephalosporins: cefatrizine and cephaloglycine inhibit the L-leucine absorption in vivo on rat jejunum. 2. This inhibition is dose and time dependent and the effect is irreversible. 3. These antibiotics have a systemic effect on L-leucine absorption. 4. The inhibition of these antibiotics affect only leucine transport, without affecting the diffusion. 5. Cefatrizine and cephaloglycine inhibit the basolateral (Na(+)-K+) ATPase activity in rat jejunum.

Animals↗
PubMedDate not supplied

[Use of troponin-I, CPK-MB and myoglobin in the diagnosis of myocardial infarct and processes of muscular necrosis of non-cardiac origin].

BACKGROUND: Thoracic pain is one of most frequent reasons for consultations at an Emergency Unit. Clinical description and the ECG are fundamental for its analysis, but a serious diagnostic problem arises when these do not provide typical data. Our aim is to analyse recently introduced biochemical parameters in order to test whether it is possible to discriminate between entities that are associated with myocardial necrosis and those others in which necrosis is due to striated muscle. MATERIAL AND METHODS: We analysed troponin-I and the relation between CPK-MB and total CPK in the serum of 45 patients who attended the Emergency Services with different processes of striated muscle in whom the total CPK was elevated, and 50 patients with acute myocardial infarct. The serum was analysed through an immunotest by fluorescence with monoclonal antibodies. RESULTS: Troponin-I proved to be above the normal value in the 50 patients with myocardial infarct an in 4 of the 45 in the muscular group. The total CPK/MB/CPK ratio was significantly higher in the infarct group than in the muscular group. In all of the patients of this latter group the relation was less than 5%. CONCLUSIONS: Troponin-I rises above the normal value and is very sensitive in a myocardial infarct. The total CPK/MB/CPK relation discriminates between processes of muscular necrosis (value <5%) and processes with myocardial infarct (that are generally associated with value >5%). The increase of troponin-I supports the diagnosis of myocardial lesion when the pain suggests a coronary origin but the ratio does not reach 5%.

English Abstract↗