Glyceryl trinitrate metabolism in the quail embryo by the glutathione S-transferases leads to a perturbation in redox status and embryotoxicity.

Exposure of stage 9 quail (Coturnix coturnix japonica) embryos to glyceryl trinitrate (GTN) induces malformations that were associated in previous studies with an increase in protein nitration. Increased nitration suggests metabolism of GTN by the embryo. The goals of this study were to characterize the enzymes and co-factors required for GTN metabolism by quail embryos, and to determine the effects of in ovo treatment with N-acetyl cysteine (NAC), a precursor of glutathione (GSH), on GTN embryotoxicity. GTN treatment of quail embryos resulted in an increase in nitrite, a decrease in total GSH, and an increase in the ratio of NADP(+)/NADPH, indicating that redox balance may be compromised in exposed embryos. Glutathione S-transferases (GSTs; EC 2.5.1.18) purified from the whole embryo (K(m) 0.84 mM; V(max) 36 µM/min) and the embryonic eye (K(m) 0.20 mM; V(max) 30 µM/min) had GTN-metabolizing activity (1436 and 34 nmol/min/mg, respectively); the addition of ethacrynic acid, an inhibitor of GST activity, decreased GTN metabolism. Peptide sequencing of the GST isozymes indicated that alpha- or mu-type GSTs in the embryo and embryonic eye had GTN metabolizing activity. NAC co-treatment partially protected against the effects of GTN exposure. Thus, GTN denitration by quail embryo GSTs may represent a key initial step in the developmental toxicity of GTN.

Período de permanência de espermatozoides em glândulas hospedeiras de espermatozoides e glândulas infundibulares em codorna de corte / Stay period of sperm in sperm-storage glands and in infundibular glands in quails

Para determinar o tempo de permanência de espermatozoides nas glândulas hospedeiras de espermatozoides (GHEs) e nas glândulas infundibulares (GIs) de codorna de corte (Coturnix coturnix coturnix), foram utilizados 12 machos e 66 fêmeas, totalizando 78 codornas em fase reprodutiva. As fêmeas foram distribuídas em 11 grupos e acasaladas por 24 horas em gaiolas individuais. Os machos, utilizados de modo intercalado, foram separados do contato com as fêmeas e colocados em descanso. As aves do grupo-controle (G0 - seis fêmeas) foram abatidas no início do experimento, enquanto as 60 fêmeas acasaladas foram distribuídas em 10 grupos (G1 a G10, com seis fêmeas cada) e abatidas a cada período de 24 horas, de forma sequencial. Fragmentos foram obtidos da região uterovaginal e do infundíbulo e submetidos às análises histológica, histoquímica e histométrica com técnicas de rotina. Os resultados morfométricos mostraram que 46% das GHEs continham espermatozoides em seu lume no primeiro dia após o acasalamento, diminuindo gradativamente nos dias posteriores chegando a 3% no quinto dia. Nesse período, os espermatozoides ascendem em direção às GIs, onde permanecem viáveis e férteis por, pelo menos, 96 horas após deixarem as GHEs, possibilitando a postura de ovos férteis por 10 dias, em média, após o acasalamento.

Sperm-Storage Tubules (SSPs) and Infundibular Tubules (ITs) are the structures responsible for sperm storage in the oviduct of birds, snakes, alligators and turtles after mating. Aiming to determine length of stay of sperm-storage tubules (SSPs) and infundibular tubules (ITs) cutting quail, Coturnix coturnix coturnix, we used 12 males and 66 females, totaling 79 quails in the reproductive phase. The females were allocated into 11 groups and mated for 24 hours in individual cages. The males used were merged and separated from contact with females and placed at rest. The poultry of the control-group (G0 six females) was slaughtered at the beginning of the experiment, the 60 previously mated females were allocated into 10 groups (G1 to G10, with six females each) and were slaughtered sequentially. On the 10th day, the last group (G10) was shot. The fragments obtained from the utero-vaginal region and the infundibulum of each female underwent histological techniques, immunohistochemistry and morphometry routine. The morphometric results showed that GHEs had 46% of the sperm in his heat on day 1 after mating, decreasing gradually in the after days reaching 3% on day 5. At this time they increase toward the infundibular tubules, where they remain viable and fertile for at least another 96 hours (4 days) after leaving the SSPs, allowing these birds to lay fertile eggs for 10 days on average after mating.

Developmental and posthatch effects of in ovo exposure to 2,3,7,8-TCDD, 2,3,4,7,8-PECDF, and 2,3,7,8-TCDF in Japanese quail (Coturnix japonica), common pheasant (Phasianus colchicus), and white leghorn chicken (Gallus gallus domesticus) embryos.

An egg injection study was conducted to confirm a proposed model of relative sensitivity of three avian species to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-like chemicals. It was previously reported that the order of species sensitivity to in ovo exposure to TCDD, 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), or 2,3,7,8-tetrachlorodibenzofuran (TCDF) at doses ranging from 0.044 to 37 picomoles (pmol)/g egg was the chicken (Gallus gallus domesticus), common pheasant (Phasianus colchicus), and Japanese quail (Coturnix japonica) based on embryo mortality and hepatic enzyme induction. In the present study, the incidence of developmental deformities, changes in body and relative organ masses, and organ pathology of hatchlings as additional indicators of species sensitivity were assessed; in addition, embryo mortality in the three species was categorized by stage of development. Embryo mortality varied temporally with significant increases generally occurring after organogenesis and just prior to hatching. A significant increase in the percentage of developmental deformities was observed only in Japanese quail exposed to TCDF. Body and relative organ masses of quail, pheasants, and chickens dosed in ovo with TCDD, PeCDF, or TCDF were not consistently affected. Chemical-related pathology occurred only in livers of quail at the greatest doses of each compound. These results indicated that the incidence of developmental deformities, changes in body and relative organ masses and organ pathology could not be used as indicators of species sensitivity or chemical potency.

Head skeletal abnormalities associated with the throat tuft mutation (hfdTt) in the Japanese quail.

Hereditary abnormalities of head skeleton ascribed to embryonic visceral arch defects were investigated in Japanese quail homozygous for the throat tuft mutation (hfdTt). Differential staining for bone and cartilage of 15-day embryos revealed partial deletion or irregularity in the mandible, basiparasphenoid, hyoid apparatus, and quadratojugal bones, incidences of which were 84, 44, 40, and 18%, respectively. Incidence of the head-skeleton abnormality was 88% when individuals having at least one of the abnormalities mentioned were regarded as abnormal. Throat tuft (hfdTt) and ear tuft (hfd) homozygotes showed distinct differences between them, although both alleles are associated with visceral arch defects.