ABSTRACT
OBJECTIVE To investigate the effects of aerobic exercise on enteric nervous injury in rats exposed to malathion.METHODS Adult male Wistar rats were treated with non-load swi mming every other day,three ti mes a week,each one hour,for six weeks.Before exercise,the rats were trea-ted with malathion 100 mg·kg -1·d -1 by oral gavage,six days a week,for six weeks.The activities of seru m acetylcholinesterase(AChE)and butyrocholinesterase(BuChE)were determined.In addition,the s mall intestinal propulsion indexes were measured.Also,the distribution of nerve plexus in ileu m was observed.The i mmunohistoche mical method was used to measure the levels of protein gene-related petide 9.5 (PGP9.5),substance P (SP),and vasoactive intestinal peptide (VIP).RESULTS Co m-pared with normal control,malathion exposure decreased the activities of seru m AChE and BuChE (P<0.01 ),increased the s mall intestinal propulsion indexes (P <0.05).In addition,the levels of PGP9.5 decreased (P<0.05).At the sa me ti me,the levels of SP increased,and the levels of VIP decreased (P<0.05).Aerobic exercise did not change the activites of cholinesterases,but decreased s mall intes-tinal propulsion indexes,increased the levels of PGP9.5,decreased the levels of SP,and increased the levels of VIP.Co mpared with the malathion exposure only,the rats in malathion ad ministration co mbined with aerobic exercise group de monstrated much lower activites of cholinesterase (P <0.01 ),and the s mall intestinal propulsion indexes decreased fro m (89 ±4)% to (79 ±5)%(P <0.01 ).Moreover,the levels of PGP9.5 increased fro m 0.012 ±0.003 to 0.029 ±0.015 (P <0.01 ).At the sa me ti me,the levels of SP decreased fro m0.174 ±0.067 to 0.1 10 ±0.057(P<0.05),and the levels of VIP increased fro m 0.0076 ±0.0029 to 0.01 1 1 ±0.0047 (P <0.05).The levels of above para meters were sa me or close to those of the normal control.CONCLUSION Malathion exposure induced disorders of enteric nervous syste m in rats,and the aerobic exercise abated the toxic response in enteric nervous syste m of malathion exposure rats.However,these effects were not mediated through recovery of cholinesterases inhibition.
ABSTRACT
Phthalate esters (PAEs)are by far the most widely used plasticisers and are categorized as high and low,depending on their molecular weight.Because of their extensive use,humans are most likely exposed to PAEs in the workplace and home environment through direct as well as indirect sources.Injection,inhalation,intravenous injection and skin absorption are potential pathways of expo-sure.With respect to health effects,phthalates are often classified as endocrine disruptors because of their ability to interfere with the endocrine syste m in the body.Furthermore,PAEs possess reproductive toxicity because of their influence on development of the reproductive system in infancy and development and differentiation of germ cells in adults.PAEs promote pathogenesis and development of liver cancer by activating peroxisome proliferator-activated receptor (PPAR)and DNA methylation.In addition, PAEs,which inhibit the i mmune functions of macrophages and pro mote hypersensitive response,pos-sess immunotoxicity.PAEs are also carcinogens that promote pathogenesis and development of cancers including breast,ovarian and so me other cancers.