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At least 361 records · Page 20Linked to original sources
PubMed1996

Quaternary nitrogen compounds affect carnitine distribution in rats. Particular emphasis on edrophonium.

Edrophonium (ethyl(m-hydroxyphenyl)dimethylamine) acutely modifies carnitine levels in different rat tissues, increasing hepatic and reducing blood and renal levels. After 2 h edrophonium treatment, the total serum carnitine levels were decreased by 16 (P < 0.001) and 33 (P < 0.001) percent in fed and fasted rats respectively compared to control, and in kidney the levels decreased by 11 (P < 0.05) and 34 (P < 0.001) percent whereas in liver the edrophonium treatment increased the levels by 43 (P < 0.001) and 59 (P < 0.001) percent. The edrophonium action does not depend on the route of administration or on the nutritional state of the animal. Its activity on carnitine levels is neither accompanied by significant variation of serum parameters of carbohydrate, fat and protein metabolism nor of insulin levels. The edrophonium activity is not related to cholinergic action, as physostigmine and ambenonium at concentrations known to increase cholinergic activity do not modify carnitine distribution in tissues. Trimethylphenylammonium (TPA) and trimethyl(p-aminophenyl)ammonium (TPA.NH2), compounds structurally similar to edrophonium, are on the contrary active on levels of carnitine and this effect is not related to their cholinergic potency. In 24 h fasted rats after the TPA and TPA. NH2 treatment, the total serum carnitine levels were decreased by 32 (P < 0.001) and 13 (n.s.) percent respectively compared to control, and in kidney the levels decreased by 15 (P < 0.02) and 5 (n.s.) percent, whereas in liver the treatment increased the levels by 72 (P < 0.001) and 45 (P < 0.01) percent. Moreover atropine, an acetylcholine antagonist, affects carnitine distribution in a way similar to edrophonium. Edrophonium activity on carnitine distribution, probably affects (inter)cellular carnitine transport by direct action on plasma membrane. Effect on capillary endothelium may be responsible for its observed action on muscle contraction force in imminent ischemia.

Ambenonium Chloride↗
PubMed1983

Effect of glutamic and aspartic acids on adenine nucleotides, nitrogenous compounds and contractile function during underperfusion of isolated rat heart.

The experiments were carried out to find out whether exogenous glutamic or aspartic acid could diminish changes in the cardiac contractile function and high-energy phosphate content caused by underperfusion of isolated isovolumic rat heart. After 40 min of reduced coronary flow (from 10 to 3 ml/min) there was an almost four-fold fall in the developed pressure, and more than three-fold rise in the diastolic pressure as well as a profound fall in creatine phosphate (CP) and ATP content. Glutamic (68 mM) or aspartic (75 mM) acids were added to the perfusate after 10 min of underperfusion when the developed pressure had declined almost to the same level as was observed after 40 min and the content of CP was reduced more than two-fold. Glutamic acid completely prevented the rise in the diastolic pressure and significantly increased the CP content, as compared to its level observed before addition of glutamate, but glutamic acid did not change the developed pressure. As a result, the CP and ATP contents were three- and two-fold higher, respectively, after addition of glutamic acid as compared to control underperfused hearts. Similar, but slightly less prominent effects were observed when aspartic acid was added instead of glutamic acid. These results suggest that high concentrations of glutamic and aspartic acids can exert beneficial effects on ischemic heart muscle.

Adenine Nucleotides↗
PubMed1995

Metabolic inter-organ relations by exercise of fed rat: carbohydrates, ketone body, and nitrogen compounds in splanchnic vessels.

Fed rats were exercised until exhaustion by almost 65% VO2max on a treadmill. In 2.5 min after the exercise, blood was collected from various vessels of the splanchnic bed. Metabolites, glucose, lactate, ketone body, and nitrogencompounds in the plasma, were measured. Glucose excretion from the liver was increased by exercise, but was not significant. The absorption by the kidney decreased to 30% by exercise. Lactate was highly absorbed by the kidney, lower limbs, and digestive tract by exercise. Exercise caused a 200-300% increase of the plasma beta-hydroxybutyrate, but the absorption by the kidney and the lower limbs was decreased. These data suggest that glucose is a good carbon source for the recovery, and that lactate is more useful than glucose, but ketone body is less effective at a very early recovery phase under fed condition. Amino acid balances in each organ except digestive tract were positive showing anabolic conditions of these organs even after exhaustive exercise at fed condition. Most amino acid concentrations in the plasma tended to decrease to 60-90% by exercise. Amino acids were excreted from the digestive tract, and were eventually absorbed by the liver in both rested and exercised rat. The digestive tract, therefore, seems to be a primary amino acids pool to supply them to the liver during the inter meal. Urea excretion from the liver was more than the absorbed ammonia showing that active deamination from amino acids was carrying on. The resulted carbon skeletons of the amino acids might be used for the gluconeogenesis in the liver.

Amino Acids↗
PubMed2000

Identification of new heterocyclic nitrogen compounds from glucose-lysine and xylose-lysine maillard model systems.

Aqueous sugar (glucose or xylose)-lysine model systems were heated at 80 degrees C for 6 h with the pH maintained at a predetermined value (3, 4, or 5). Selected compounds were isolated by combinations of solvent extraction and semipreparative HPLC, prior to identification by NMR and mass spectrometry. Two compounds were identified from the pH 5 glucose system and were identified as epsilon-[2-formyl-5-(hydroxymethyl)pyrrole-1-yl]-L-norleucine (pyrraline) and the new compound, 1-(5-carboxy-5-aminopentyl)-2-formyl-3-(1,2,3-trihydroxypropyl)pyrrole. A third compound was partially characterized. 2-Acetyl-5-hydroxymethyl-5,6-dihydro-4H-pyridinone was identified in the pH 3 xylose system, and the new compound, 8-furan-2-yl-methyl-5-hydroxymethyl-5,6-dihydro-indolizine-1,7-dione, was identified in the pH 4 xylose system. 2-Furfurylidene-4-hydroxy-5-methyl-3(2H)-furanone was identified in both xylose systems. Mechanisms of formation are proposed for the novel compounds.

Chromatography, High Pressure Liquid↗
PubMed1978

Phosphorus-nitrogen compounds. 21. Murine oncolytic and antifertility effect of adamantylaziridine compounds.

P,P-Bis(1-aziridinyl)-N-adamantylphosphinic amide and N,N'-bis(ethylene)-P-(1-adamantyl)phosphonic diamide were synthesized as potential anticancer and male antifertility agents. Log P values (octanol-water) of the agents were determined and compared to calculated values. Both derivatives displayed intraperitoneal murine antileukemic activity and antifertility effects when given intraperitoneally and orally.

Adamantane↗
PubMed1978

Phosphorus-nitrogen compounds. 22. Synthesis and antitumor activity of arylsulfonylhydrazone analogues.

A series of pyridine-2-carboxaldehyde N-oxide and pyridine-2-carboxaldehyde (thio)phosphoric hydrazones and two cupric chelates was synthesized. The hydrazones, chelates, and combinations of hydrazones and cupric chloride were tested against mice bearing P388 lymphocytic leukemia, Sarcoma 180, or Ehrlich carcinoma ascites cells. The effects of various structural modifications of the hydrazones on antineoplastic activity for this latter system were determined. In general, the pyridine-2-carboxaldehyde thiophosphoric monohydrazones containing P-phenyl or P-phenoxy substituents possessed the highest activity when concurrently administered with cupric ion, whereas the ligands themselves were inactive. Two of the compounds were prepared with P-hydroxyl groups to permit increased hydrophilicity. The ability of the hydrazones to chelate cupric, ferrous, and cobaltous salts was investigated, and discrepancies between determined and calculated log P values for three compounds are discussed.

Animals↗