Research communications in chemical pathology and pharmacology最新文献

The nucleotide sequence of the cDNA encoding a sperm protein (rSMP-B) was determined in a previous study. Two peptide segments corresponding to the extracellular domain of the deduced sperm polypeptide were synthesized as multiple antigen peptide (MAP) and designated as rSMP-229 and rSMP-230. Polyclonal antibodies were raised against the two MAPs. Sera obtained from rabbits immunized with rSMP-230 interacted with human and rabbit sperm membrane proteins with estimated molecular sizes of 72 and 20.1 kD, respectively. Adult female and male rats were immunized with the MAPs and their fertilities determined. Immunization of female rats with rSMP-229 and rSMP-230 induced infertility in 25% and 83% of the treated animals, respectively. All male rats immunized with rSMP-229 remained fertile; whereas animals immunized with rSMP-230 did not mate with normal cycling female rats. Three impotent male rats were found to regain their mating potency 45 days after the last booster injection. These findings demonstrated that immunization with rSMP-230 induced a reversible impotency in male rats. Serum testosterone and LH levels were reduced in rSMP-230-immunized male rats and were elevated in rSMP-229-immunized animals. Histopathological examination of sections of testes from male rats immunized with rSMP-230 showed impairment of spermatogenesis and sloughing of germ cells into the lumen of the seminiferous tubules. The testes of male rats immunized with rSMP-229 showed normal morphology and active spermatogenesis with scattered foci of nodular hyperplasia of Leydig cells in the interstitial areas. In conclusion, immunization with synthetic peptide segments corresponding to different domains of a deduced sperm protein induced infertility in a significant number of female rats and transient impotency in male rats.

We measured soluble CD14 (sCD14), plasma endotoxin, tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), IL-6, and interferon-gamma (IFN-gamma) in patients with multiple organ failure (MOF). The sCD14 level was significantly higher in septic patients with MOF than that in those without MOF and also higher in non-septic trauma patients with MOF than that in those without MOF. In the septic group with MOF, the sCD14 level correlated significantly with the TNF-alpha level but not the plasma endotoxin, IL-1 beta, IL-6, or IFN-gamma level. These results suggest that the sCD14 level reflects the degree of pathophysiology and that TNF-alpha is involved in stimulating sCD14 production.

Following the administration of phenylhydrazine, cadmium chloride and ethanol to rats there was a marked increase in the concentration of liver lipid peroxides and a sharp decline in GSH levels. The oxidative stress generated by the action of these toxic compounds led to the induction of liver heme oxygenase, which exhibited a 3-fold increase in activity over the control value. Patients with various forms of liver disorders showed increased levels of plasma lipid peroxides as well as hyperbilirubinemia. In view of the known ability of bilirubin to cause lipid peroxidation in illuminated erythrocyte membranes, the results of the present paper suggest that in severely impaired liver, as in some liver diseases, lipid peroxides may be also produced by a mechanism involving heme oxygenase.

A novel reductive metabolism of shogaol [1-(4'-hydroxy-3'-methoxyphenyl)-deca-4-ene-3-one], a major pungent and pharmacologically active principle of ginger, was investigated in rat liver in vitro. The ethyl acetate extractable metabolites formed by incubation of this alpha,beta-unsaturated ketone with rat liver 12,000 x g supernatant fortified with NADPH-generating system were analyzed by high performance chromatography and gas chromatography/mass spectrometry. In addition to the saturated ketone and reduced alcohol metabolites, an allyl alcohol, 1-(4'-hydroxy-3'-methoxyphenyl)-deca-4-ene-3-ol, was identified as a new metabolite of shogaol. Likewise, dehydroparadol [1-(4'-hydroxy-3'-methoxyphenyl)-deca-1-ene-3-one], a non-pungent analog of shogaol, was also reduced to the corresponding allyl alcohol by the postmitochondrial fraction of rat kidney in the presence of NADPH-generating system.

The influence of stevioside, the sweet glycoside of Stevia rebaudiana leaves, on the glycogen levels of fasted rats was investigated. In one set of experiments, single doses of stevioside (200 mumol) or steviol (200 mumol) were given orally to 24-hours fasted rats, either alone or simultaneously with fructose. Under these conditions both stevioside and steviol increased the initial glycogen deposition in the liver. In another set of experiments, stevioside was given to the rats in the drinking water at the beginning of the fasting periods (5:00 p.m.) of 24 and 48 hours. Two different concentrations were given, 1.0 and 2.0 mM. Increased hepatic glycogen levels were found at 48 hours with stevioside (1.0 mM) and at 24 hours with stevioside (2.0 mM). Steviol had no effect on hepatic glycogen levels when given in the drinking water. It can be concluded that stevioside exerts a stimulatory action on hepatic glycogen synthesis under gluconeogenic conditions.

The intraperitoneal administration of flumazenil, an imidazoldiazepine with selective antagonistic properties on the central benzodiazepine receptors, induced in normoglycemic-normolipidemic rats a significant increase in blood glucose levels and significant decreases in the serum lipids.

The in vitro metabolism of FK 506 and its inhibition by other drugs was studied with hepatic microsomes from rats pre-treated with dexamethasone, a selective cytochrome P-450 IIIA inducer. Nonspecific inhibitors of cytochrome P-450, such as ketoconazole, itraconazole, fluconazole and SKF 525 A, and most of the cytochrome P-450 IIIA specific substrates used in this study significantly inhibited FK 506 metabolism. Although cyclosporine is a known substrate of cytochrome P-450 IIIA, it had no effect on FK 506 metabolism. Cytochrome P-450 II substrates had minimal but significant effect on FK 506 metabolism. This data supports our earlier observations that FK 506 metabolism is mediated predominantly by the steroid inducible cytochrome P-450 IIIA enzyme subfamily. The results of this study indicate that in transplant patients there is a potential for an interaction of FK 506 with other drugs that are metabolized by the cytochrome P-450 IIIA subfamily or those that alter the activity of cytochrome P-450 IIIA subfamily. Careful monitoring and FK 506 dosing adjustment may be necessary to maintain therapeutic concentration and minimize toxicity in patients receiving this agent.

The distribution of methylprednisolone (MPL) in various rat tissues following 2 mg/kg IV bolus doses of liposomal drug (L-MPL) and drug in solution was investigated. Animals were sacrificed at selected times post-dosing until 120 h. Liver, spleen, thymus, heart, lungs, muscle, kidney and brain were excised and the concentrations of MPL were measured using HPLC after homogenizing organs in buffer. The incorporation of MPL in liposomes did not alter the uptake of drug by heart, lung and muscle. Drug concentrations in brain were undetectable. In the kidney the MPL concentrations after 1 h were higher for liposomal drug and not detectable at later time points. Tissue to plasma partition coefficients were close to unity in lung, heart, and muscle at 1-2 h after the dose of drug in solution and increased by 7.5 times for spleen and 6 times for thymus after the dose of L-MPL. There were no significant differences between the weights of organs expressed in percent of body weight. These results demonstrate that, while the sequestration of L-MPL by lymphatic tissues occurred, the uptake of drug by the other tissues did not increase. This may be beneficial for preferential targeting of the immune system.

As part of our ongoing work to develop the new non-isotopic assay method carbonyl metalloimmunoassay (CMIA), whose efficacy has already been proven in the laboratory for phenobarbital and cortisol, we here present the steps involved in establishing CMIA of 5,5 diphenylhydantoin (DPH), one of the most commonly used antiepileptic medications. First, anti-DPH antibodies were obtained by injection of the immunogen DPH-3-valerate-BSA into rabbits. The titer value and specificity of these antibodies were examined by RIA using [14C]-DPH as tracer, and an antibody batch selected for its high titer value and good specificity for metabolites of DPH and other antiepileptic drugs. Next the organometallic complex Cr(CO)3-DPH, chosen as the CMIA tracer, was synthesized and shown to conserve a high recognition value for anti-DPH antibodies (CR = 200%). Isopropyl ether was selected as the best organic solvent for use in separating the free and bound fractions of the tracer. Employing the Cr(CO)3-DPH complex as tracer and FT-IR spectroscopy as the detection method, we were able to obtain a titration curve by CMIA using an amount of tracer identical to that used in RIA. The titer value obtained in CMIA is approximately twice that obtained by RIA. These results demonstrate the feasibility of DPH assay by the CMIA method.

In this study, we analyzed effects of copper toxicity on the process of mitosis by examining polyploid accumulation and histone H1 hyper-phosphorylation, which result from defects in mitotic completion, in regenerated LEC rat liver. The proportion of polyploids with 8c nuclear DNA content in LEC rats was significantly higher than that in normal rats (P < 0.05). The degree of histone H1 phosphorylation was about 2.5-fold higher in LEC rat than normal rat. These results suggest that the accumulated copper in LEC mutant rat causes the block of mitotic completion in cell cycle.