Contractile activity of isolated rat small intestine after chronic inhalation exposure to dioctyl terephthalate

Introduction. Dioctyl terephthalate (DOTP) is an ester of 2-ethylhexanol and terephthalic acid. It is a new generation plasticizer that is used as a more environmentally friendly and safer substitute for dioctyl phthalate (DOP) and other phthalates. Despite the established low level of toxic effects on the human body, the expansion of industrial production of DOTP requires an in-depth assessment of its safety.

Material and methods. The effect of DOTP on the motility of isolated segments of the small intestine of rats was assessed under chronic inhalation exposure for 120 days at concentrations of 3.4 and 18.6 mg/m³.

Results. The course exposure to dioctyl terephthalate, regardless of the dose, reduces the spontaneous contractile activity and adrenoreactivity of the smooth muscle cells of the rat small intestine, and also increases their sensitivity to cholinergic effects.

Limitations. The study demonstrates a change in the spontaneous contractile activity isolated segments rat small intestine under the influence of the main mediators autonomic nervous system. Additional research is required for a detailed assessment possible mechanisms for the development of the identified changes.

Conclusion. As a result of the study, it was found that chronic inhalation of dioctyl terephthalate at concentrations of 3.4 and 18.6 mg/m³ equally cause a decrease in the tone and amplitude of contractions in isolated segments of the rat small intestine. Chronic exposure to DOTP leads to a change in the reactivity of small intestine myocytes to mediators of the autonomic nervous system. The results obtained indicate that DOTP, when administered by inhalation, is enterotropic.