Effects of Dietary Administration of CL-20 on Japanese QuailCoturnix coturnix japonica

Abstract

Hexanitrohexaazaisowurtzitane, or CL-20, is an emerging highly energetic compound currently under consideration for military applications. With the anticipated wide use of CL-20, there is the potential for soil and groundwater contamination resulting in adverse toxicologic effects on environmental receptors. Presently, there is a lack of data describing the toxic effects of CL-20 on avian species. The present study describes the effect of CL-20 on Japanese quail (Coturnix coturnix japonica) modified from standard toxicity test guidelines. First, a 14-day subacute assay was adopted using repeated gavage doses (0, 307, 964, 2439, 3475, or 5304 mg CL-20/kg body weight (BW)/d for 5 days followed by no CL-20 exposure (vehicle only) for 10 days. Second, a subchronic feeding assay (0, 11, 114, or 1085 mg CL-20/kg feed) was done for 42 days. During both studies, no overt toxicity was observed in the CL-20-treated birds. During the first 5 days of the subacute study, CL-20-exposed birds showed a dose-dependent decrease in BW gain, whereas increased liver weight, plasma sodium, and creatinine levels were observed in birds receiving the highest dose tested. For the subchronic study, embryo weights were significantly decreased in a dose-dependent manner. Embryos from CL-20-exposed birds were observed to have multiple cranial and facial deformities, beak curvatures, possible mid-brain enlargement, and classic one-sided development with micro-opthalamia (nonstatistical comparisons with control embryos). A trend toward decreased number of eggs laid per female bird was also observed. We conclude that CL-20 (or its degradation products) elicits few effects in adults but may affect avian development, although these preliminary findings should be confirmed.

In vitro degradation of hexanitrohexaazaisowurtzitane (CL‐20) by cytosolic enzymes of Japanese quail and the rabbit

“…Biologically significant effects such as multiple cranial and facial deformities, beak curvatures, possible midbrain enlargement, and classic one‐sided development with micro‐opthalamia (nonstatistical comparisons with control embryos) were also observed. A trend toward decreased number of eggs laid per female bird was also observed [4]. These data would indicate that CL‐20 may have been biotransformed in vivo in the liver and that the effects observed on hepatic parameters are early indicators suggestive of liver injury.…”

“…We have shown earlier that 15‐d subacute and 42‐d subchronic treatment of CL‐20 to adult quail led to increased liver weights and elevated plasma aspartate transferase activities in treated birds, suggestive of early indications of liver injury [4]. Despite these effects, CL‐20 was not detected in the plasma or in selected organs (brain, spleen, heart, and liver) of CL‐20–treated birds.…”

“…The CL‐20 was quantified by HPLC‐ultraviolet (UV) as previously described [4]. For the determination of [ 14 C]CL‐20 and its biotransformation products, an HPLC system composed of a Waters 717 Plus autosampler (Waters, Milford, MA, USA), a Model 128 Beckman (Beckman Coulter, Fullerton, CA, USA) pump, LC‐CN column (25 cm × 4.6 mm i.d., 5‐μm particles; Supelco, Bellefonte, PA, USA), a Beckman UV detector λ = 230 nm), and a radioisotope detector (In/Us) was used.…”

“…This study also reported the absence of CL‐20 in adult quail plasma and the major organs (liver, brain, heart, and spleen) despite the described changes in the plasma and liver chemistry. In the same subchronic study [4], embryo weights were significantly decreased in a dose‐dependent manner with the unbounded lowest‐observed‐adverse‐effect level at 11 mg/kg feed. Biologically significant effects such as multiple cranial and facial deformities, beak curvatures, possible midbrain enlargement, and classic one‐sided development with micro‐opthalamia (nonstatistical comparisons with control embryos) were also observed.…”

“…Recently, our laboratory investigated the toxic effects of CL‐20 on the gallinaceous test species, the Japanese quail ( Coturnix coturnix japonica ) [4], and demonstrated that subchronic feeding CL‐20 in the diet to adult quail (up to 1,085 mg CL‐20/kg body wt, for 42 d) increased liver weights and elevated plasma aspartate aminotransferase activities in treated animals in the highest dose group. However, no overt toxicological effects were observed in the CL‐20–treated birds.…”