ABSTRACT
Morphine and tramadol which have analgesic effects can be administered acutely or chronically. This study tried to investigate the effect of these drugs at various times by using different methods of administration [intraperitoneal, oral, acute and chronic]. Sixty adult female rats were divided into six groups. They received saline, morphine or tramadol [20 to 125 mg/Kg] daily for 15 days. A hot plate test was performed for the rats at the 1[st], 8[th] and 15[th] days. After drug withdrawal, the hot plate test was repeated at the 17[th], 19[th], and 22[nd] days. There was a significant correlation between the day, drug, group, and their interaction [P<0.001]. At 1[st] day [d1], both morphine, and tramadol caused an increase in the hot plate time comparing to the saline groups [P<0.001], while there was no correlation between drug administration methods of morphine and/or tramadol. At the 8[th] day [d8], morphine and tramadol led to the most powerful analgesic effect comparing to the other experimental days [P<0.001]. At the 15[th] day [d15], their effects diminished comparing to the d8. After drug withdrawal, analgesic effect of morphine, and tramadol disappeared. It can be concluded that the analgesic effect of morphine and tramadol increases with the repeated use of them. Thereafter, it may gradually decrease and reach to a level compatible to d1. The present data also indicated that although the analgesic effect of morphine and tramadol is dose-and-time dependent, but chronic exposure to them may not lead to altered nociceptive responses later in life
Subject(s)
Animals, Laboratory , Morphine/administration & dosage , Tramadol/administration & dosage , Time Factors , Time , Drug Administration Routes , RatsABSTRACT
Gonadotropin-releasing hormone [GnRH] is a reproductive key hormone. The GnRH analogues are widely used in in vitro fertilization and treatment of sex hormone-depended cancers induced by the materials used in chemotherapeutic agents. The aim of this study is to evaluate the effects of cyclophosphamide and decapeptyl [analogues of GnRH] on histomorphometry and stereology of testicular tissue as well as gonadotropic and gonadal hormones indices in mice. For this study, 24 adult male Balb/C strain mice were divided in four groups; first, cyclophosphamide [65 mg/kg/body weight [BW]], second, decapeptyl [0.05 mg/kg/BW], third, decapeptyl at first, and after 10 days of cyclophosphamide injection, and control group was received same volume of sterile saline. In order to evaluate the tissue changes in testes of the mice, sections were prepared and stained with Hematoxylin-Eosine, Periodic Acid Schief's [PAS] and Oil-Red-O staining techniques. The cyclophosphamide causes histomorphologic changes in the testicular tissue; whereas such changes by decapeptyl were comparatively mild. The morphometric results revealed significant reduction in diameters of seminiferous tubules [p=0.02], and the stereological results confirmed significant differences in spermatogenesis [SI] as well as rate of tubal differentiation [TDI] indices between experimental and control groups [p=0.001]. In addition, the morphometric findings proved that, there are significant decrease [p=0.001] in thicknesses of epithelia and stereologic result revealed reduction in number of cell layers in both decapeptyl and chemotherapy groups, but the decrements of these parameters were significant [p=0.02] in later group. In groups that had received cyclophosphamide, and decapeptyl alone, the LH and testosterone levels were decreased significantly [p=0.03], whereas in those that had received decapeptyl along with cyclophosphamide, the LH and FSH levels showed a decline but the level of testosterone increased. These results demonstrated that, analogue of GnRH i. e., decapeptyl protect morphologic, morphometric, and stereologic alterations of the testes tissue, as well as gonadotropic and gonadal hormonal changes preceding cyclophosphamide treatment in male mice