Muscle and liver protein synthesis and degradation in growing rats fed a raw field bean (Vicia faba L.) diet

Body weight gain, food intake, gastrocnemius muscle and liver weight, protein and RNA content, as well as the fractional rates of muscle and liver protein synthesis (ks, according to the method of constant infusion of L-[14C]tyrosine), growth (kg) and degradation (kd), along with RNA activity (g of protein synthesized per day/g RNA) of both organs, were determined in growing male rats fed ad libitum over a period of 10 days on 18.7% protein diets containing either casein (5% of methionine added) (control) or the raw legume field bean (Vicia faba L.) as the sole sources of protein. It has been found that as compared to control rats, those fed the raw legume diet exhibited a significant reduction in the rate of growth, muscle RNA, ks, kg, kd and RNA activity, and a significant increase in liver ks, kd and RNA activity. All differences were statistically significant at least at the 5% level. The possible nature of these findings is discussed.     

Electrophoretic and immunological characterization of pollen protein ofZea mays races

Electrophoretic and serological studies with proteins extracted from the pollen of 12 races of maize (Zea mays) have proved valuable in distinguishing among these races. Both sodium dodecyl sulfate-polyacrylamide gel electrophoresis and double immunodffusion (Ouchterlony method) were used to analyze the extracted pollen proteins. Jaccard's similarity coefficient was calculated from the data generated by 2-state scoring of the band patterns obtained in each system. Average linkage cluster analysis of the similarity matrices was used to construct phenograms illustrating the similarity among the extracts. The racial groupings indicated in these pheno grams, when compared with those of several morphological studies, show some general agreement. However, there are differences, the most notable being that Chalqueno appeared the most dissimilar of the races studied and that Dulce showed high similarity to Palomero Toluqueño, rather than being an exceptional race as it is usually considered. The possible bearing of the groupings of the races in these phenograms with respect to genetic lineage and selection of maize is discussed.     

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.     

Inhibition of intestinal absorption of 5-methyltetrahydrofolate by fluoxetine

Thein vitro uptake of 5-methyltetrahydrofolate (5-MeTHF) by rat and human intestine is dose-dependently inhibited by the antidepressant drug fluoxetine (FLX). In rat jejunum rings, 0.2 mM FLX inhibited the uptake of 5-MeTHF (0.25 μM) by 32% (15 min) and 49% (45 min). In brush border membrane vesicles (BBMV) from rat jejunum, 0.2 mM FLX inhibited the folate uptake at the overshoot (90 s) by 40 %. Similar inhibition was observed with human Caco-2 cells and duodenal biopsies. FLX action is exerted on the active transport component of the folate uptake, since the drug has no effect when the passive diffusion component becomes prominent by high substrate concentration, or by 0-4 ºC incubation or by addition of the folate transport inhibitor DIDS (1mM). The kinetic analysis with rat BBMV suggests a non-competitive inhibition of the 5-MeTHF transport by FLX, with apparent values for K_M = 0.89 μM, Vmax = 1.89 pmol/mg prot./10 s, and K_I = 0.21 mM. After 21 days of treatment with FLX (10 mg/kg/day), the folate uptake by jejunum rings or by BBMV from the treated rats was diminished, and the folate levels in erythrocytes and serum were also decreased.