Effect of chronic toxoplasmosis on levels of some neurotransmitters (Dopamine, Adrenaline, and Noradrenaline) in human serum Mahdi Taher Sahib AL-Hadad, Raad Abbas Kadhim * , Abeer Fauzi Al-Rubaye * Biology department, College of sciences for women, University of Babylon, Iraq Abstract Latent Toxoplasma gondii infection has been considered asymptomatic for many years, but results of recent studies have associated it with various neuropsychiatric problems, including Alzheimer’s, Schizophrenia, Parkinson, Depression, Epilepsy. These chronic disease occur as a result of changes in the levels of hormones and neurotransmitters caused by parasitic infection in the host brain. A total of 45 blood samples of donors (33 men and 12 women) from AL-Najaf province, Iraq were tested for IgG anti-Toxoplasma antibodies by Elisa method and the results as follows 17 seropositive(12 male and 5 female) and 28 seronegative (21 male and 7 female). All samples were subjected to Elisa test to determine levels of three of neurotransmitters (Dopamine, Adrenaline, and Noradrenaline) in serum. The result show significantly (t test) higher serum levels of Adrenaline in patients with latent toxoplasmosis compared to controls (p<0.05). Both Dopamine and Noradrenaline hormones serum levels in patients showed a slight increase compared with control group, but statistically insignificant (p>0.05). Our findings suggest that chronic infection by T. gondii causes a change in some neurotransmitters and may be explained by the occurrence of certain neurological diseases in the incidence of latent toxoplasmosis. Keywords: Latent toxoplasmosis, Neurotransmitters , Dopamine. INTRODUCTION Toxoplasma gondii is a protozoan parasite that is main or final host is cat but intermediate host is mammals and birds 1 . It is estimated that 30–50% of the world suffers from toxoplasmosis, the incidence of toxoplasma infection in younger peoples has decreased from 20 – 25% to 10% in the United states of American and several countries in Europa during the past fifteen years, at same time, the incidence increased from about 5% – more than 10% in some Asian countries 2 . In Iraq the seroprevalence of toxoplasmosis vary according to age, gender and region, they were ranging from 19-45% 7 - 3 , T. gondii infection causes various neurological disease in host and alters neurological signaling pathways 8 . Toxoplasma gondii as chronic infection producing distinctive neuropsychiatric diseases and alterations in its intermediate hosts, (humans and rodents) 9 . Miscellaneous human diseases that correlated with chronic T. gondii infection, including Alzheimer’s 10,11 schizophrenia 12-14 Parkinson 15-18 depression 19 epilepsy 20 . Its induce behavioral changes in human 21-23 and rodents 24 , also a significant association between T. gondii infection and suicide attempts was reported 25 . Many studies correlated these symptoms with alterations in hormones concentrations in host, that include sex hormones 21,26-29 and neurotransmitters hormones 23,30 . One factor that pay to the vague changes and neurological disorder in human and animal is modulate of neurotransmitters levels during chronic toxoplasmosis such as dopamine 31 . In this paper we attempt to emphasis role of chronic toxoplasmosis in changes of three neurotransmitters levels in human serum. MATERIALS AND METHODS Forty-five samples (33 men and 12 women) of AL-Najaf province, Iraq aged 52.2±16.5 years were taken to investigate chronic toxoplasmosis using the Elisa method(IgG anti-Toxoplasma antibodies)(Calbiotech Inc.,). five ml of blood were withdrawn from each person. The serum was isolated in eppendorffs tubes and kept at -80°C until use. Serum concentrations of Three neurotransmitters (Dopamine, Adrenaline, and Noradrenaline) were measured using Elisa method (Elabscience biotechnology Co., Ltd) and the results were expressed at mean ± standard deviation for both the total experiment and the control group. Statistical analysis was used with a single-tailed t- test and a 5% probability level using Microsoft Excel 2010. RESULTS Table 1 shows the population characteristics of the samples under study. The levels of neurotransmitters (Dopamine, Adrenaline, and Noradrenaline) were monitored. The levels of hormones in case or patients group (seropositive IgG Toxoplasma antibodies persons) and in control group (seronegative IgG Toxoplasma antibodies persons) in human serum were presented in table (2). The result show significantly higher serum levels of Adrenaline in patients with latent toxoplasmosis compared to controls (p<0.05).Both Dopamine and Noradrenaline hormones serum levels in patients showed a slight increase compared with control group, but statistically insignificant (p>0.05). Table 1: Demographic data in current study. Categories +ve IgG Toxoplasma -ve IgG Toxoplasma total Samples 17(37.8%) 28(62.2) 45 Male 12 21 33 Female 5 7 12 Age (year mean ±sd) 52.3±17.5 52.2±16.2 52.2±16.5 Mahdi Taher Sahib AL-Hadad et al /J. Pharm. Sci. & Res. Vol. 11(2), 2019, 402-405 402