Journal of the Egyptian Society of Parasitology, Vol. 24, No. 3, December 1994 J. Egypt. Soc. Parasitol., 24 (3) 1994: 627 - 632 EFFECT OF PRAZIQUANTEL ON SEX HORMONE LEVELS IN MURINE SCHISTOSOMIASIS MANSONI By KARIM F. ABDALLA, SAMIR M. ABDEL AMANY F. EL FAKAHANY., AZZA S. EL-HAMSHARY AND LAILA M. AFIFI.* Depariment of Parasitology, Benha Faculty of Medicine, Benha Branch of Zagazig University and Department of Radioisotope*, A.E.A., Egypt. ABSTRACT Changes in sex hormonal levels were studied in Schistosoma mansoni infected and praziquantel treated mice (400 x 2 mg/Kg), drug control and in normal control groups. It was observed that schistosomiasis lead to increase in the level of testosterone, progesterone and 17B - esteradiol, 60 and 70 days post- infection in male and female mice, respectively. In praziquantel treated group the level of testosterone was lowered 10, 20 & 30 days post treatment, progesterone and 17 -estradiol fell 30 days post treatment after primary rise. The mechanism of recorded changes will be discussed in details. INTRODUCTION Hormonal changes have been reported in patients with hepatosplenic schistosomiasis (El-Ridi et al, 1987). Ghareeb (1973) reported that since most of the pituitary stimulating hormones are protein in nature, one would expect a decrease in their synthesis in hepatic affection, with consequent diminution in the release of sex and other hormones. Liver derangement may also reflect itself by diminished hormonal inactivation resulting in increased plasma level of these inactivated hormones. Studies devoted to the interaction between schistosomicidal drugs, hormonal changes and state of disease immunopathology in schistosomiasis have been limited. In this work, the - 627 -