Determination of Dichlorvos Effect on Uterine Contractility Using Wavelet Transform

Highlights

• Effects of different doses of dichlorvos on isolated uterus muscle contractions are evaluated.

• Wavelet scalogram analysis is preferred in the study because of its simultaneous time, frequency and energy screening capability.

• Obtained results show that:

  • Increasing doses of dichlorvos decreases the energy and frequency of contractions,

  • The results showed that 50 and 100 μM dichlorvos concentrations decrease the energy of contractions significantly.

• The study is important in that it shows toxic effects of DDVP on uterus which is responsible for reproductive function of mammalians and that it draws attention to an important public health problem. Furthermore, this is the first study showing that the wavelet transform can be readily utilized to determine the effects of insecticides and similar chemicals on the uterus spontaneous activity.

Abstract

Purpose: The use of organic synthetic pesticides has increased heavily in recent years and organophosphate insecticides constitute 20–38% of the total pesticides used worldwide. Dichlorvos, an organic phosphate insecticide, is widely used for the control of the agricultural, industrial and domestic pest in most of the agricultural countries like Turkey and it is known that many chemical toxins are capable of producing changes in uterine contractions. In this study, the effects of different doses of dichlorvos on isolated uterus muscle contractions are evaluated.

Methods: Wavelet scalogram analysis is preferred in the study because of its simultaneous time, frequency and energy screening capability.

Results: Obtained results show that 50 μM and 100 μM doses of DDVP significantly decreased the energy of contractions.

Conclusions: The study is important in that it shows toxic effects of DDVP on uterus which is responsible for reproductive function of mammalians and that it draws attention to an important public health problem. Furthermore, this is the first study showing that the wavelet transform can be readily utilized to determine the effects of insecticides and similar chemicals on the uterus spontaneous activity.

Introduction

The use of organic synthetic pesticides has increased about 40-fold in 21st century. Pesticides are used to kill or control pests. Organophosphates, organochlorines, carbamates and pyrethroids are various groups of pesticides used worldwide. Currently, among the various groups of pesticides, organophosphates are in a major and most widely used group. The first organophosphate, tetraethyl pyrophosphate, was developed and used in 1937. In a quick time, several other organophosphorus pesticides were industrialized and commercialized. Globally, organophosphate insecticides constitute 20–38% of the total pesticides used [1]. Insecticides can damage various organs of human beings, including nervous, endocrine, reproductive, cardiovascular, respiratory and gastrointestinal systems, by different routes of exposure [2], [3], [4], [5], [6], [7]. The organophosphate insecticide dichlorvos (2,2-dimethyl-dichlorovinyl phosphate, DDVP) is widely used in agriculture and at home for the control of pest. Like all organophosphate insecticides, dichlorvos inhibits activity of acetyl-cholinesterase, an enzyme responsible for the hydrolysis of acetylcholine. In addition to neurotoxicity, dichlorvos leads to nephrotoxicity, hepatotoxicity, genotoxicity and reproduction toxicity in non-target organisms [8], [9], [10], [11].

Uterine contractions are important in many different reproductive functions including sperm and embryo transport, implantation, menstruation, gestation and parturition. Irregular uterine activity may underlie common and important disorders such as infertility, implantation failure, dysmenorrhea, endometriosis, spontaneous miscarriage or preterm birth [12]. Many chemical toxins are capable of producing changes in uterine contractions [13], [14], [15], [16], [17]. Wrobel et al. [13] examined effects of DDT and its metabolite (0.1, 1, 10 or 100 ng/ml) on the function of epithelial cells and muscle strips of bovine oviducts from 1 to 5 day of the estrous cycle. They concluded that oviductal secretion of prostaglandins is affected by DDT and DDE. In the study of Mlynarczuk et al. [14], luteal cell and myometrial stripts from a cow at early pregnancy were treated with the chloro-organic compounds (1 or 10 ng/ml). They suggested that chloro-organic compounds can influence uterine contractions and increase the risk of abortions in pregnant females. Criswell et al. [15] showed the lindane-induced inhibition of spontaneous activity in pregnant rat uterus. The effects of the essential oil of Mentha pulegium that is used in folk medicine as an abortifaceant, were assessed on the isolated rat myometrium by Soares et al. [16], and they showed the inhibitory effects of the essential oil of the Mentha pulegium on the isolated rat myometrium. Wrobel et al. [17], investigated the adverse effects of aldrin and dieldrin on both myometrial contractions and secretory functions of bovine ovaries and uterus in vitro. Obtained results showed that aldrin and dieldrin inhibit myometrial contractions.

In recent years, some mathematical approaches such as Fourier transform, wavelet transform, and neural networks have been applied to analyze uterine spontaneous signals [18], [19], [20]. Wavelet transform has an important place among them with its superior performance in analyzing nonstationary biological signals [21]. Because of that, there exist wide range of studies such as on the analysis of uterine signals [22], [23], cardiac health and electrocardiography (ECG) [24], [25], [26], and electroencephalography (EEG) and electromyography (EMG) signals [27], [28], [29] in literature, in all of which the wavelet transform is utilized in analysis of the signals. In this study, the effects of different doses of DDVP on isolated uterus muscle contractions are evaluated by using wavelet scalogram analysis. Although there are studies which investigate the effects of various chemicals on uterine contractility, to the best of our knowledge, wavelet analysis has not previously been applied to test the effects of insecticides on the uterine contractions.