Biomedical subjects

M F San Martín

Publications and source records attributed to M F San Martín.

3 recordsLinked to original sources

PubMed2002

Chiral inversion of (R)-(-)-fenoprofen in guinea-pigs pretreated with clofibrate.

The influence of clofibrate on the stereoconversion of fenoprofen (FPF) was studied in guinea pigs. This hypolipidaemic agent has been related to some biochemical changes in the liver leading to an increase in the chiral inversion process. Two groups of animals (n = 6 per group) were pretreated with oral doses of clofibrate (280 mg/kg per day) for three days and were then given (R)- or (S)-FPF (5 mg/kg, IV). The FPF enantiomers were extracted from the guinea-pigs' plasma using a solid phase procedure and analysed by HPLC with previous derivatization with L-leucinamide. Pretreatment with clofibrate increased the chiral inversion of (R)-FPF in favour of the pharmacologically active (S)-FPF enantiomer. Before this metabolic interaction can be applied to therapy with fenoprofen, the toxic effects of (S)-(+)-FPF on the gastrointestinal and renal tracts and the interference by (R)-(-)-FPF with the metabolism of lipids should be thoroughly evaluated.

Animals↗

PubMed2002

Food processing by high hydrostatic pressure.

The use of high hydrostatic pressures (HHP) for food processing is finding increased application within the food industry. One of the advantages of this technology is that because it does not use heat, sensory, and nutritional attributes of the product remain virtually unaffected, thus yielding products with better quality than those processed traditional methods. HHP have the ability to inactivate microorganisms as well as enzymes responsible for shortening the life of a product. In addition to lengthening the shelf-life of food products, HHP can modify functional properties of components such as proteins, which in turn can lead to the development of new products. Equipment for large-scale production of HHP processed products are commercially available nowadays. Guacamole, sliced ham, oysters, and fruit juices are some of the products currently available on the market. HHP technology is one of the most promising nonthermal processes.

Consumer Behavior↗

PubMed1994

Nicotinamide late protective effects against carbon tetrachloride-induced liver necrosis.

Nicotinamide (NIC) is known to increase the synthesis of pyridine nucleotides and also to inhibit the hydrolysis of them to ADP-ribose, which in turn is involved in Ca2+ release from mitochondria via the ADP ribosylation of crucial mitochondrial proteins. In this work, we test the potential ability of NIC to be a late protective agent against CCl4-induced liver necrosis. We observed that 1 g/kg po NIC, 30 min before or 6 or 10 hr after CCl4 (1 ml/kg), given ip as a 20% (v/v) solution in olive oil, was able to significantly prevent the necrogenic effect of the hepatotoxin at 24 hr as evidenced by determination of isocitric dehydrogenase activity in plasma or by histological observation. NIC administration 6 hr after CCl4 prevented fatty liver induced by hepatotoxin at 24 hr. NIC did not modify CCl4-induced lipid peroxidation process at 1 hr after CCl4 and decreased the covalent binding of 14CCl4 to lipids. NIC decreased the levels of 14CCl4 reaching the liver when given 30 min before hepatotoxin but not when given 6 hr after it. NIC lowered body temperature of rats at 1, 3, and 6 hr and augmented it at 24 hr after CCl4. NIC concentrations in liver as determined by GC/MS/SIM analysis were 21 micrograms/g liver 1 hr after administration and 53 micrograms/g at 3 hr. Late preventive effects of NIC against CCl4 induced liver necrosis when given at 6 or 10 hr after CCl4 are compatible with the hypothesis that NIC restores mitochondrial ability for Ca2+ uptake. This hypothesis remains to be proved and is being further challenged in our laboratory.

Animals↗