Page 1058 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

990 SECTION | XV Mycotoxins

VetBooks.ir been studied. Immunotoxic effects in poultry are lympho- dietary AFs decrease male fertility (Ibeh et al., 1994). A
study at an infertility clinic showed that there is a correla-
cytopenia, reduced T cell counts, and reduced native
tion between dietary levels and serum levels of AFs. The
resistance to disease. Exposure to AFs can increase or
decrease the immune response to vaccinations. The more mean AF levels in serum were 1.660 6 0.04 μg/mL (infer-
constant finding is a decreased response to vaccination tile men) and 1.041 6 0.01 μg/mL (fertile men). The infer-
to Newcastle virus, fowl adenovirus serotype-4, and tile men had a higher percentage (50%) of abnormal
dinitrochlorobenzene-induced hypersensitization. Exposure spermatozoa and AF in their semen. Exposure to AFs
of hens can cause immune dysfunction in chicks. increases fetal loss. Women with high serum levels of
AFB 1 -lysine adduct ($11.34 pg/mg of albumen) are at
greater risk for delivering a child with low birth weight.
Reproductive and Teratogenic Effects
Women with increased blood levels of AFM 1 have
AFs can impair reproductive performance and prenatal increased risk to give birth to a baby with abnormally low
exposure can have adverse in utero/in ovum effects. The birth weight.
observed effects of AFs in mature roosters are testicular
degeneration, a reduction in plasma testosterone, reduc-
TOXICOPATHOLOGY OF AFLATOXINS
tion in testicular mass and altered hormonal response. In
hens, exposure to AFs reduces egg production and egg
Clinicopathology
hatchability. Pregnant rats (P 1 ) were administered AFB 1
intramuscularly from day 12 to day 19 of pregnancy Acute aflatoxicosis causes changes in clinicopathology
(Supriya and Reddy, 2015; Supriya et al., 2016). The off- parameters and these changes can occur before the onset of
spring (F 1 ) were evaluated for anatomical morphology clinical signs. The activities of liver enzymes in serum are
and tested to determine developmental, behavior and increased and the increased activity is indicative of hepatic
damage. Increased activity of hepatic enzymes in serum
response to physical stress. The birth weight of the F 1
pups exposed to AFB 1 in utero was significantly less than includes γ-glutamyl transpeptidase (transferase) (GGT),
controls. For the F 1 offspring in both studies, the behav- aspartate aminotransferase (AST), alkaline phosphates
ioral evaluations (cliff avoidance, negative geotaxis, right- (ALP), sorbitol dehydrogenase (SDH), ornithine carbamyl
ing from supine position and ascending wire mesh, and transferase (OCT), and isocitrate dehydrogenase (ICD).
locomotor and exploratory activities) were impaired. For Once released into serum the activities of hepatic enzymes
the F 1 females, there was a delay in sexual maturity (vagi- decrease as metabolic processes remove the hepatic
nal opening), prolonged corticosterone response to stress, enzyme from serum. The activities of hepatic enzymes in
irregular estrus, and at maturity, decreased fertility. For serum that have been reported to be the most consistently
the F 1 males, body weights, and the relative weights of elevated in aflatoxicosis are GGT, AST, ALT (nonrumi-
the testis, cauda epididymis, prostate, seminal vesicles, nants), and SDH. Serum bilirubin levels are also increased
and liver were decreased on postpartum day 100. and in ruminants, photosensitization can occur. Serum pro-
Spermatozoa parameters were reduced in the F 1 males. teins can decrease in aflatoxicosis, or albumin and
The numbers of viable and mobile sperm were reduced β-globulins decrease and γ-globulins increase. Elevated
and the numbers of abnormal sperm were increased. serum bilirubin and ALT, low cholesterol, may be a predic-
Exposure to AFB 1 in utero also decreased serum testoster- tor of a fatal outcome of aflatoxicosis in dogs (Bruchim
one and fertility indices. In F 1 males, testosterone, and et al., 2012). Prolonged prothrombin and activated partial
activity of testicular hydroxysteroid dehydrogenases were thromboplastin times also are a guarded prognosis. A leu-
significantly decreased in a dose-dependent manner with kocytosis may or may not occur. Thrombocytopenia
a significant increase in the serum follicle-stimulating increases the likelihood of concurrent diffuse intravascular
hormone and luteinizing hormone. Deterioration in the coagulation. In poultry, a decrease in erythrocyte numbers,
testicular and cauda epididymal architecture was observed hemoglobin, and leukopenia consisting of heteropenia and
in the F 1 generation rats from exposed P 1 females. lymphopenia can occur. The timing of hepatic enzyme
Fertility studies on the exposed F 1 generation revealed a determinations in terms of the pathogenesis of aflatoxicosis
significant decrease in the mating index rats with an is important. The rate of enzyme release from hepatic cells
increase in the pre- and postimplantation losses in rats and the half-life of the enzyme in serum must be consid-
mated with prenatal AFB 1 -exposed males. In pigs, sows ered in interpretation of laboratory findings as well as non-
exposed to AFs are at risk for increased fetal loss, birthing hepatic sources of the enzymes. The activity of GGT in
piglets with reduced birth weight. Harvested porcine serum has a slower temporal decrease than AST.
oocytes exposed in vitro to AFB 1 have impaired maturity. Dehydration must be considered in interpretation of serum
The effects of AFs on human reproduction have been proteins and in advanced aflatoxicosis, multiorgan shut-
reviewed (Shuaib et al., 2010b). There is evidence that down can occur. Hemorrhage can alter the hematology