Metabolism and disposition of luminol in the rat.

1. The metabolism and disposition of Luminol (LMN, 3-aminophthalhydrazide), a widely used forensic and laboratory reagent that chemiluminesses upon oxidation, was determined as part of its overall toxicological characterization. 2. Radiolabelled LMN was well absorbed, metabolized and excreted following p.o. administration of a range of doses. About 90% of the total dose was recovered within 24 h of administration in urine in the form of two metabolites identified as LMN N8-glucuronide and LMN N8-sulphamic acid. 3-Aminophthalic acid, the oxidative product of LMN in the light-emitting reaction, was apparently not formed in vivo. 3. Metabolism and disposition of an i.v. administered dose was similar to that following gavage. Little or no LMN-derived radioactivity was present in tissue within 12 h post-dosing. Excretion of radioactivity in bile following i.v. injection was minimal (approximately 8% of the total dose in 6 h) and consisted of the same urinary-excreted glucuronide and sulphate conjugates. 4. LMN was not absorbed dermally in rat, potentially a major route of exposure to human. If the fate of LMN is similar between species, this compound should have little potential for either dermal absorption, bioaccumulation in tissues following other routes of exposure or chronic toxicity in humans.

Phenomenon of specific inhibition of luminol-dependent chemiluminescence of polymorphonuclear leukocytes under the influence of allergen.

The purpose of our investigation was to establish how the intensity of induced luminol-dependent chemiluminescence of polymorphonuclear leukocytes is affected by the cultivation of allergen with the blood of allergic patients (pollinosis, bronchial asthma and penicillin allergy) and animals with allergic processes (Arthus' phenomenon, guinea pigs sensitized by horse serum). The results of all assays were uniform. In all cases three phases of changes in induced chemiluminescence were established. In the first phase with the minimum doses of specific and unspecific allergens, either no changes in chemiluminescence were found or chemiluminescence even increased. With higher doses of allergen came the second phase - inhibition of stimulated chemiluminescence when specific allergen had been added and the absence of changes in the tests with unspecific allergen. We defined this phase as the phase of specific chemiluminescence inhibition. With a further increase in the concentration of allergen came the third phase. It expressed itself in the inhibition of stimulated chemiluminescence under the influence of both specific and unspecific allergen. We viewed this phase as a manifestation of the toxic influence of allergen on polymorphonuclear leukocytes. We suggested using the second phase for diagnosing sensitization.

The effect of aurothiomalate on the oxidative burst of polymorphonuclear leukocytes varies with the quantity of drug in myocrisin ampoules.

The antirheumatic drug, sodium aurothiomalate (GSTM), is not a well defined substance and chemical changes occur in the heat sterilization of the commercial ampoules (Myocrisin). In a comparison of the pharmacological properties of Myocrisin with freshly prepared solutions of GSTM, their effects on the chemiluminescence of polymorphonuclear leukocytes (PMN) activated by phorbol myristate acetate (PMA) were studied. Chemiluminescence was measured in the presence of GSTM from solid material and from Myocrisin ampoules. Myocrisin from 1 and 5 mg ampoules and GSTM in fresh solutions heated at 95 degrees C for 30 min inhibited chemiluminescence, whereas Myocrisin from the higher strength (10-50 mg) ampoules and GSTM in unheated solutions showed no effect at low concentrations and enhancement of chemiluminescence at higher concentrations. Since the gold complexes present in the different strength Myocrisin ampoules do not have identical biological effects, the use of GSTM in investigational studies should involve consideration of its source.

Disposition of the hypolipidaemic agent, 2,3-dihydrophthalazine-1,4-dione, in Sprague Dawley rats.

The disposition of [14C]2,3-dihydrophthalazine-1,4-dione, a potent hypolipidaemic agent, has been determined after both intravenous and oral administration. Both the routes of administration afforded multi-exponential disposition with an estimated t1/2 of approximately 75 h. After oral administration, the drug was observed to be absorbed rapidly from the intestine and distributed quickly to all tissues of the body. A large quantity of the 14C-radioactivity was found in the skin and carcass. Approximately 35% of the administered radioactivity was excreted in urine after oral administration and 11% in the faeces. Approximately 66% of the radioactivity excreted in urine was the parent drug. There was evidence of an additional metabolite which accounted for 28% of the urinary radioactive excretion. The parent drug has little serum protein binding, is highly water soluble, and is probably taken up by cells by passive diffusion.

Detection of iron-porphyrin proteins with a biochemiluminescent method in search of extraterrestrial life.

Iron-porphyrin proteins (catalase, peroxidase, hemoglobin, cytochrome C) represent an important group of redoxenzymes which have vitally important functions in micro-organisms. A biochemiluminescent method was employed for the detection of iron-porphyrin proteins. The reaction of luminol oxidation with H2O2 is accompanied by chemiluminescence. The rate of hydrogen peroxide decomposition increased 10(5)-10(7) -fold in the presence of the above enzymes as compared with ferrous (or ferric) ions. Possible application of this reaction for the detection of iron-porphyrin proteins of microbial origin was studied. Other authors have suggested this reaction for the detection of extraterrestrial life. Kinetics of the above reaction in the presence of iron-porphyrin proteins were shown to differ both in amplitude and duration of the signal from the pattern observed in the presence of non-hemin catalysts. The reaction pattern in the presence of mixed-soil populations is similar to those observed with pure bacterial cultures and individual iron-porphyrin proteins. Photometric tests revealed that among preparations studied the addition of 0.01% lysozyme was the most effective in destroying cell walls in microbial populations. However, removal of cell walls is not a necessary prerequisite for the detection of iron porphyrin since, for effective luminol oxidation with H2O2 the medium should be kept at pH 12.0. Pretreatment of microbial suspensions with ultrasound increased 2-fold the total signal due to iron porphyrins. The above method gives a reproducible signal indicating the presence of iron porphyrins when sterile nutrient media were innoculated with desert soil samples (Repeteck, Kara-Kum) and incubated for 13 hr. The device was able to detect the presence of no less than 10(5) - 10(6) cells per ml. The addition of limonite (Fe2O3 X nH2O) does not result in the appearance of an appreciable signal in the luminol + H2O2 system.