No abstract

TRENHOLM. 1983. Fusarium toxins in field corn. I. Time course of fungal growth and production of deoxynivalenol and other mycotoxins. Can. J. Bot. 61: 3080-3087. The formation of the trichothecene mycotoxins deoxynivalenol and 15-acetyldeoxynivalenol and zearalenone in field corn inoculated with Fusarium grarninearum was studied over a growing season. The mycotoxins, ergosterol, colony forming units, weight, moisture, and ash contents were measured in the infected ears. Measurements of toxins and ergosterol in infected plants, weather data, and analyses of the soil mycoflora were also taken. In the infected ears, fungal propagule counts rapidly increased up to 6 weeks after inoculation and then sharply declined. Ergosterol concentrations followed the propagule data for the first 6 weeks and then levelled off (at about 70 pprn). Deoxynivalenol concentrations increased (to about 580ppm), over the same period and then declined (to about 430 pprn); 15-acetyldeoxynivalenol concentrations rose rapidly in the first 2 weeks (to 64 ppm) and then slowly declined (to 20 pprn); an appreciable amount of zearalenone (10 ppm) was not observed until 9 weeks after inoculation. The data indicated that the relative and absolute concentrations of the two trichothecenes present in the corn may have been affected by the plant, and toxins were found throughout the plant but mainly in the infected part. MILLER, J. D., J. C. YOUNG et H. L. TRENHOLM. 1983. Fusarium toxins in field corn. I. Time course of fungal growth and production of deoxynivalenol and other mycotoxins. Can. J. Bot. 61: 3080-3087. La formation de mycotoxines chez le mays auquel le Fusarium grarninearum a Ct C inoculC a Ct C CtudiCe pendant une saison de croissance; les mycotoxines CtudiCes comprennent la zCaralCnone et deux trichotCcknes, le dCsoxynivalCno1 et le 15-acCtyl-dtsoxynivalCno1. Les mycotoxines, I'ergostCrol, les unit& formant des colonies, le poids, I'humiditC et la teneur encendres ont Ct C mesurCs dans les Cpis infect&. Des mesures des toxines et de I'ergostCrol dans les plantes infectCes, des donnCes mCttorologiques et des analyses de la mycoflore du sol ont aussi Ct C effectdes. Dans les Cpis infectts, le nombre de propagules fongiques augmente rapidement jusqu'a 6 semaines aprks l'inoculation, puis il diminue brusquement. La concentration d'ergostkrol suit le nombre de propagules pendant les 6 premihes semaines, puis se stabilise i environ 70 ppm. La concentration de dCsoxynivalCno1 augmente (jusqu'i 580 ppm) pendant la meme pCriode, puis elle diminue (jusqu'i 430 pprn environ); la concentration de 15-acCtyl-dCsoxynivalCno1 augmente rapidement (jusqu'i 64 ppm) pendant les 2 premikres semaines, puis elle diminue lentement jusqu'i 20 ppm; la zCaralCnone n'a pas Ct C observCe en quantitCs agprkciables (10ppm) avant la 9" semaine suivant l'inoculation. Les donnCes montrent que les concentrations relatives et absolues des deux trichothCcknes prksentes dans le mays ont pu etre affectCes par la plante. Les toxines se rencontrent dans toute la plante, mais sur...

No abstract

Consumption of corn or corn-based products contaminated with Fusarium moniliforme/fumonisins has been associated with a variety of animal and human diseases and is a major food/feed safety issue. This study focused on the clinical toxicity and performance parameters in growing swing exposed to low to moderate levels of pure fumonisin B1 (FB.) for 8 weeks. Male (castrated) and female pigs were fed diets containing 0,0.1,1.0, and 10 mg FB1/kg diet (ppm). Weight gains and feed consumption were measured weekly. Blood samples were collected throughout the study, and various clinical and hematological parameters were measured. Because fumonisins are potent inhibitors of sphingolipid biosynthesis, sphinganine and sphingosine concentrations were determined in the liver, lung, and kidney. Organ weights and carcass quality were measured at the end of the trial. In general, male pigs were more adversely affected by FB1 in the diet than females. The average daily gain for males decreased by 8% for pigs fed 1.0 ppm and by 11% at 10.0 ppm, when compared to the control (0 ppm). Males fed 0.1 ppm showed an erratic growth pattern during the first 5 weeks of the experiment. Feed consumption for the same animals was somewhat higher than that of the controls during each of the first 4 weeks but thereafter was 6-7% lower each week as compared to controls. Female pigs fed FB1-diets showed a general enhancement of feed consumption until week 4. Among clinical chemistry parameters, cholesterol increased in males for the 1.0 and 10.0 ppm diets as compared to controls after 2 weeks, while the levels in both sexes were elevated for the 1.0 ppm diet only by the end of the experiment. Serum liver enzyme concentrations were altered during week 2 only. Changes were observed in the weight of the pancreas and adrenals for male pigs fed FB1 diets as compared to controls. The free sphinganine to free sphingosine ratio (biomarker of exposure in FB1-consuming animals) increased in all three organs for the 10 ppm diet, regardless of sex. The study indicated that FB1 can cause different effects at each dose level, at concentrations as low as 0.1 ppm (showing erratic growth) followed by a reduced growth and biochemical abnormalities in blood (1.0 ppm) and sphingolipid alterations in tissues (10.0 ppm). Some of these effects occurred below the exposure level that caused alteration in sphingolipid metabolism.

The pharmacokinetics of the mycotoxin fumonisn B1 (FB1) were investigated in pigs. Animals were administered 14C-FB1 intravenously (IV; 0.25 microCi, 0.40 mg/kg) or intragastrically (IG; 0.35 microCi, 0.50 mg/kg); separate groups of pigs underwent bile cannulation prior to dosing (groups IV/B and IG/B, respectively). Blood, urine, faeces, (and bile), were collected at specific time intervals over 72 hr, and assayed for specific activity. Following IV dosing, plasma concentration-time profiles were triexponential, with the following mean values: t1/2 alpha, 2.2 min; t1/2 beta, 10.5 min; t1/2 gamma, 182 min; apparent volume distribution (Vd gamma), 2.4 l kg-1; plasma clearance, 9.1 ml min-1 kg-1. After 3 days, clearance of FB1-derived radioactivity from the body had slowed to trace levels; total recoveries in urine and faeces were 21.2% and 58.3%, respectively. In bile-interrupted pigs (IV/B) the absence of the slow terminal elimination phase (gamma) suggested FB1 underwent enterohepatic circulation. Biliary recovery was 70.8% of the IV-dose. Radioactivity remaining in tissues after 72 hr amounted to 19.8% and 11.9% of the dose given to IV and IV/B pigs, respectively; highest activities were measured in liver and kidney equivalent to 1,076 and 486 ng FB1 and/or metabolites per g tissue, respectively. Based on plasma and excretion data, systemic bioavailability following IG dosing was estimated to be a very limited 3-6%. Tissue residue levels following IG dosing were 10-20-fold less than IV dosing.