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Biomedical subjects

J Larralde

Publications and source records attributed to J Larralde.

At least 55 records · Page 3Linked to original sources
PubMed1987

Liver and muscle proteolytic activity in male growing rats fed a field bean (Vicia faba L.) diet.

Total liver cathepsin A and D and gastrocnemius acid proteolytic activities have been evaluated in male growing rats fed ad libitum over periods of 15 and 30 days on 20%-protein diets containing either casein or raw field bean (Vicia faba L.) as protein sources. It has been found that, compared to the control casein-fed rats, those fed the legume diet exhibited a marked reduction (p less than 0.05) in the rate of growth and protein efficiency rate; liver proteolytic activity increased with ageing in the two dietary treatments and was found to be significantly higher (p less than 0.05) in the legume-fed rats. However, muscle proteolytic activity decreased with ageing and proved significantly increased (p less than 0.05) in the legume-fed rats.

Animals↗
PubMed1987

IC50 of trifluoperazine and RMI 12330A for the theophylline and phloretin-induced increase in intestinal D-galactose accumulation.

The effect of trifluoperazine and RMI 12330A on D-Galactose accumulation was studied in isolated rat intestinal mucosa. Both drugs inhibited the theophylline and phloretin-induced increase in tissue sugar accumulation in a concentration-dependent fashion, with IC50 values close to 10(-6) M. These findings suggest that calmodulin might mediate the theophylline and phloretin actions on galactose transport in intact rat ileum.

Animals↗
PubMed1987

Liver and muscle proteolytic activity in field bean (Vicia faba L.) fed birds. Effect of vitamin E.

Liver and muscle proteolytic activities (cathepsin A and D) were measured in growing male chickens fed ad libitum over periods of 30 and 60 days on 20% protein diets containing either heated soybean (HSB, control) or raw field bean (RFB, Vicia faba L.) as the main sources of protein. Vitamin E (250 mg/100 g diet) was added or not to the RFB diet. It has been found that in comparison to control HSB-fed animals, RFB-fed birds showed a significant reduction in the rate of growth, together with a significant increase in the activities of both cathepsins A and D in liver and muscle. The addition of vitamin E to the RFB diet had no significant effect on either weight gain or liver and muscle proteolytic activities. The possible nature of these effects is discussed.

Animals↗
PubMed1987

[Role of polyphenols in the low nutritive value of Vicia faba].

The inclusion of field bean (Vicia faba) in diets for growing experimental animals, reduced their growth performance in a similar way as compared with controls fed a casein diet, with 0.2% tannic acid. Hydroalcoholic extracts or isolated tannins obtained from Vicia faba seeds, decreased the intestinal transport of D-glucose. The addition of 0.05, 0.1 or 0.2% of tannic acid to the perfusion solutions containing D-glucose proportionally diminished the intestinal uptake of sugar according to its poliphenolic content. It has been postulated that polyphenols reduce, at least partially, the nutritive value of legumes, by altering monosaccharide absorption. Other constituents, however, could also be involved.

Animals↗
PubMed1987

Effect of amoxicillin on galactose transport across rat small intestine.

The effect of amoxicillin on galactose absorption across rat small intestine was investigated by using in vivo and in vitro techniques. Amoxicillin caused a dose-related, time-dependent, and reversible inhibition in intestinal sugar transport. Intestinal galactose transport was not affected when the drug was perfused in an adjacent loop. Also, intestinal oxygen consumption was not impaired by amoxicillin. Amoxicillin decreased the apparent affinity of galactose for the carrier system, while both its maximum absorptive capacity and the phlorhizin-insensitive component of sugar absorption remained unaltered.

Amoxicillin↗
PubMed1986

Role of calcium in the phloretin effects on sugar transport in rat small intestine.

The effect of phloretin on D-galactose transport in rat small intestine has been investigated. Phloretin enhanced tissue sugar accumulation and reduced mucosal to serosal D-galactose fluxes. Calcium-deprived bathing solutions and verapamil significantly reduced, but did not abolish, the phloretin-effects on intestinal galactose transport. Furthermore in the presence of the anticalmodulin drugs, RMI 12330A and trifluoperazine, phloretin was without effect on D-galactose transport. These findings suggest that phloretin may reduce serosal sugar permeability via an increase in Ca2+-calmodulin complex.

Animals↗
PubMed1986

Induced biochemical and physiological changes in young and adult growing rats fed on a vegetable or animal protein diet.

The influence of diets containing faba bean or casein as sources of protein were studied in rats at two stages of development. A significant impairment of growth rate, carcass, liver and skeletal muscle were found in young and adult rats fed for a period of 10 days on raw legume. Urinary urea output and the activities of three amino acid degrading enzymes: arginase, alanine aminotransferase and arginine succinate synthetase were all affected by the dietary protein and the stage of development. Urinary creatinine excretion was higher in the adult rats, while serum cholesterol was slightly increased in the young ones. Changes in plasma zinc may be attributed to a reduced zinc bioavailability to rats from the faba bean diet. Other biochemical parameters measured (glucose, triglycerides and plasma proteins) remained unchanged in all the experimental groups. Liver DNA and RNA content (mg/g tissue) decreased with age in both dietary groups, which were accompanied by an increase in tissue size. Furthermore, liver RNA concentration (primarily a measure of protein synthesis capacity) was enhanced in the adult legume fed rats. In this context, it is suggested that other organs (particularly muscle, with lower amino acid requirements for protein synthesis as a consequence of the stunting of growth) could contribute to increase the amino acid supply to liver in the animals fed on the faba bean diet.

Alanine Transaminase↗
PubMed1986

Effect of cephalexin and tetracycline on galactose absorption in rat small intestine.

The effects of cephalexin and tetracycline HCl on D-galactose absorption in rat small intestine were investigated. Both antibiotics inhibited D-galactose uptake into isolated intestinal mucosa in a dose-dependent fashion. In vivo studies showed that cephalexin and tetracycline HCl reduced D-galactose absorption and that the transport defect was not reversible on cessation of antibiotic perfusion. Both the active and passive components of D-glactose absorption were inhibited by the antibiotics tested. Furthermore, both drugs reduced mucosa O2 consumption and inhibited D-galactose absorption when they were perfused in a contiguous loop. We conclude that the diminished D-galactose transport by rat small intestine after tissue exposure to either cephalexin or tetracycline HCl appears to be in part due to an insufficient energy supply.

Animals↗
PubMed1985

Calcium-dependence of sugar transport in rat small intestine.

The involvement of Ca2+ in the theophylline action on sugar transport was investigated in isolated rat small intestinal mucosa. Theophylline significantly increased cell water free sugar accumulation and reduced mucosal to serosal sugar fluxes both in the presence and absence of calcium, but the effects of theophylline were significantly less in calcium free media. In theophylline untreated tissues, calcium-deprived bathing solutions decreased tissue galactose accumulation and increased mucosal to serosal sugar flux. The calcium-channel blocker verapamil produced similar effects on intestinal galactose transport to those induced by low extracellular calcium activity. RMI 12330A and the calmodulin antagonist trifluoperazine abolished the theophylline-effects on intestinal galactose transport. Both drugs also affected sugar transport in basal conditions. These studies suggest that calcium might modulate sugar permeability across the basolateral boundary of rat enterocytes, and that its effect may be mediated by calmodulin.

Animals↗
PubMed1985

Intestinal iodide secretion and its dependence upon mucosal I- permeability.

Iodide secretion across different regions of rat small intestine has been investigated in vitro using the standard Wilson-Wiseman technique. Net I- secretion was observed along the entire small intestine, being significantly higher in the central region. Anaerobic conditions, ouabain (2 mM) and Na+ free Ringer solution prevented net I- secretion, whilst both theophylline (1 mM) and carbachol (0,1 mM) enhanced the observed basal intestinal I- secretion. Furthermore, Ca2+-deprived bathing solutions significantly reduced intestinal I- secretion. Epithelial I- uptake from both mucosal and serosal sides was measured by using a Ussing-type chamber technique. The initial rate of I- uptake across the mucosal membrane was significantly higher in the central region than in the proximal part of rat small intestine. No significant differences were observed in the rate of I- uptake from the serosal side. These studies suggest that mucosal I- permeability might determine the direction of net I- intestinal transport and that cytosolic Ca2+ may be a physiological regulator of intestinal I- transport.

2,4-Dinitrophenol↗
PubMed1984

Influence of diets containing different levels of Vicia faba L. as source of protein on body protein composition and nitrogen balance of growing rats.

Rats fed on Vicia faba as source of protein grew less than those fed a casein control diet. However, no differences were found on protein content of whole body, liver, muscle, and myofibrillar fraction. Nitrogen balance values were significantly higher in animals fed the casein diet than in those nourished with V. faba as source of protein. Minor differences due to the protein level of the diets were found. Retained nitrogen values were similar in all dietary groups. The inclusion of V. faba in the diet did not affect specifically muscle mass and protein distribution. It is suggested that differences reported in nitrogen balance are a consequence, at least in part, of the impairment of growth, although some other factors must be involved in this phenomenon.

Animals↗
PubMed1984

An automatic method for determination of urinary and myofibrillar 3-methylhistidine: fractional rate of myofibrillar protein breakdown in rats fed on casein as source of protein.

An automatic, more rapid and simplified analytical system for determination of 3-methylhistidine in urine and skeletal muscle is described, which may be applied to more extensive studies of large number of samples within a reasonable period of time and constitutes a powerful tool in understanding the dynamics of protein metabolism in the intact organism. This procedure allows the analysis of 3-Methylhistidine by ion-exchange chromatography in 140 +/- 2.5 min using a single column system. The mean urinary 3-Methylhistidine output of rats weighing about 200 g fed on an adequate diet of casein was 0.84 +/- 0.02 microM/100 g BW, and the mean values for skeletal muscle in these animals were 0.74 +/- 0.03 microM/g tissue. The fractional rate of myofibrillar protein breakdown assessed by the urinary 3-Methylhistidine was 0.028 +/- 0.002%.

Animals↗