Sperm quality in mice acutely treated with parathion

Aim: To investigate the toxic effect of a single injection of the organophosphorous agropesticide, parathion, on sper-matogenesis in immature male mice. Methods: Seven-day old mice received a single injection of parathion intraperi-toneally at a dose of 1/3 LD_50. The epididymal sperm count, sperm morphology and chromatin thermal stability wereanalyzed 28 and 50 days after injection. Results: Sperm counts were decreased and teratozoospermia and thermal de-naturation of DNA increased after parathion injection. Sperm parameters were changed to a greater extent in younger an-imals, denoting a higher lability of spermatogenic process at its beginning. The damages could recover a long time afterparathion administration. Conclusion: Organophosphorous agropesticides are testicular toxicants, eliciting reversiblecytotoxic and cytogenetic alterations in germ cells.

Electrochemical Assay of Effects of Organophosphate Poisoning on Acetylcholinesterase from Pheretima via 2,6-Dimethyl-p-benzoquinone

Electroanalytical techniques could be a reliable and promising alternative to classical and sophisticated methods because of their simplicity（small and portable）,easy use,the ability to deliver fast response with high sensitivity and selectivity.A square wave voltammetric method was developed for the assessment of organophosphorus（OPs） compound impact on acetylcholinesterase（AChE） of Pheretima with 2,6-dimethyl-p-benzoquinone（2,6DMBQ） as a redox indicator.The substrate of acetylthiocholine is hydrolyzed by AChE and the produced thiocholine reacts with 2,6-DMBQ to give an obvious shift of electrochemical signal.The reduction peak of 2,6-DMBQ is located at around 0.18 V which is far away from the oxidation potential of possible interference components often present in biosample.The decreased rate of reduction current was related with the activity of AChE.The inhibition of parathion-methyl on AChE was assessed.The inhibiton rate of OPs on AChE activity increased quickly during the first 10 min inhibition,and after that the value of inhibition rate approached to be constant.AChE lost almost 29.3% of activity after 10 min incubation with 1 μg/mL parathion-methyl and 67.5% of activity with 10 μg/mL parathion-methyl,while the activity that corresponds to 40 μg/mL parathion-methyl was nearly completely inhibited（94.9%）.Compared to cyclic voltammetry and amperometry,Square wave voltammetry（SWV） method is a high sensitive electroanalysis with fast scan-rate（only several seconds for one signal value） which is useful to prevent the electrodes from possible fouling or passivation.This method can be employed to assess the inhibition of organophosphate on AChE and investigate OPs impact on environmental animals.

Ultrastructure of mouse teratozoospermia induced by parathion

Male fertility has been correlated to sperm counts,motility and morphology. Wyrobek et al (1983),evaluating changes in sperm morphology caused bychemicals (including some pesticides) found that analysisof teratozoospermia is a useful tool to asses testiculartoxicants. In view of their wide agricultural use and scarcereproductive information available regarding organo-

Synthesis,GC-EIMS,~1H NMR,^(13)C NMR,Mechanistic and Thermal Studies of o-Xylylene-α,α'-bis (triphenylphosphinebromide)

Organophosphorous compounds containing phosphorus as an integral part have been widely used in industry, organic synthesis and optoelectronics, o-Xylylene-a,a＇-bis（triphenylphosphinebromide）（OXBTPPB） is a facile reagent to convert o-quinones（e.g., 9,10-phenanthrenequinone） into polycyclic aromatic hydrocarbons（PAHs）. Herein lies an improved synthetic route to OXBTPPB. The resultant was carefully characterized with GC-EIMS, ^1H NMR, ^13C NMR, spectroscopic techniques. The EIMS shows characteristic peaks at m/z=262.4, 183.3, 108.2, 77.1 attributed to the [C18H15P]^＋, [C12H8P]^＋, [C6H8P]^＋, [C6H5]^＋ ions, respectively. The ^1H and ^13C NMR spectrum shows well resolved peaks and all the hydrogens and carbons were well-assigned via a combined study of ^1H-^1H COSY, HMBC, and HMQC experiments. The mechanism for the formation of OXBTPPB was proposed based on literature and obtained experimental data. Meanwhile, the thermal stability of OXBTPPB was evaluated with TGA analysis, and an onset decomposition temperature（Td） was recorded at 323.6 ℃.