Subsequent effect of subacute T-2 toxicosis on spermatozoa, seminal plasma and testosterone production in rabbits

Abstract

Pannon White (n 5 12) male rabbits (weight: 4050 to 4500 g, age: 9 months) received 2 ml of a suspension containing purified T-2 toxin by gavage for 3 days. The daily toxin intake was 4 mg/animal (0.78 to 0.99 mg/kg body weight (BW)). Control animals (n 5 12) received toxin-free suspension for 3 days. Since a feed-refusal effect was observed on the second day after T-2 administration, a group of bucks (n 5 10) were kept as controls (no toxin treatment) but on a restricted feeding schedule, that is, the same amount of feed was provided to them as was consumed by the exposed animals. On day 51 of the experiment (i.e. 48 days after the 3-day toxin treatment), semen was collected, and pH, concentration, motility and morphology of the spermatozoa, as well as concentration of citric acid, zinc and fructose in the seminal plasma, were measured. After gonadotropinreleasing hormone (GnRH) analogue treatment, the testosterone level was examined. One day of T-2 toxin treatment dramatically decreased voluntary feed intake (by 27% compared to control, P , 0.05) and remained lower ( P , 0.05) during the first 2 weeks after the withdrawal of the toxin. BW of the contaminated rabbits decreased by 88% on days 17 and 29 compared to controls ( P , 0.05). No effect of toxin treatment was detected on pH and quantity of the semen or concentration of spermatozoa. The ratio of spermatozoa showing progressive forward motility decreased from 65% to 53% in the semen samples of toxin-treated animals compared to controls ( P . 0.05). The ratio of spermatozoa with abnormal morphology increased ( P , 0.05) in the ejaculates collected from the toxin-treated animals. T-2 toxin applied in high doses decreased the concentration of citric acid in seminal plasma ( P , 0.05). No effect of T-2 toxin on the concentrations of the other seminal plasma parameters (fructose and zinc) was observed. T-2 toxin decreased the basic testosterone level by 45% compared to control ( P , 0.01) and resulted in lower ( P , 0.05) GnRH-induced testosterone concentration. Feed restriction, that is, less nutrient intake, resulted in more morphologically abnormal spermatozoa in the semen, but it did not cause significant loss in BW, motility of the spermatozoa, composition of the seminal plasma or testosterone concentration -its effect needs further examination.

Effect of chronic T-2 toxin exposure in rabbit bucks, determination of the No Observed Adverse Effect Level (NOAEL)

“…In the first experiment T-2 was extracted and purified according to the methodology described previously (Kovács et al, 2011). Treated animals received 0.05, 0.1 or 0.2 mg/animal/day T-2 toxin, while control animals received toxin free suspension by gavage for 65 days.…”

“…The testosterone concentration was determined with a direct 3 H-radioimmunoassay method (Csernus, 1982) adopted and validated for rodents' (chinchilla, rabbit and Angora rabbit) plasma (Kulcsar and Huszenicza, unpublished), described in details previously (Kovács et al, 2011).…”

“…The effect persisted until 5 month after withdrawal of the moldy hay (Alm et al, 2002). The subsequent effect of T-2 applied to rabbits in larger doses (4 mg/animal/day for 3 days) was manifested by a decreased sperm motility, increased number of spermatozoa with morphological abnormalities, decrease in concentration of citric acid in seminal plasma, and decrease in testosterone concentration after 48 days following a 3-day long sub-chronic toxicosis (Kovács et al, 2011). Interaction of T-2 with reproduction in rabbits was reported by WHO (2001), but the studies were criticized due to their poor description.…”

T-2 mycotoxin slows down the development of mouse blastocysts, decreases their blastomere number and increases chromatin damage

“…These abnormalities include retarded ovulation and decreased progesterone production (Huszenicza et al, 2000), disrupted corpus luteum maturation (Ványi et al, 1995), inhibited granulosa cell proliferation (Caloni et al, 2009), as well as reduced sperm motility and testosterone production (Kovács et al, 2011).…”

Effects of T-2 mycotoxin on in vitro development and chromatin status of mouse embryos in preimplantation stages

“…It is well documented that T-2 can cause reproductive disorders both in male and female individuals. These abnormalities are examples for retarded ovulation and decreased progesterone production (Huszenicza et al, 2000), disrupted corpus luteum maturation (Ványi et al, 1995), inhibited granulosa cell proliferation (Caloni et al, 2009), and reduced sperm motility (Kovács et al, 2011).…”