Effects of high doses of diazepam on carrageenin-induced paw edema in rats

Benzodiazepine (BDZ) receptor sites play a relevant role in immune/ inflammatory reactions. Acute BDZ treatments were shown not only to suppress cell proliferation in rat thymus but also to decrease TNF-alpha, IL-1 and IL-6 release from adult mouse macrophages. In the present investigation the effects of acute (l0.0 and 20.0 mg/kg) and long-term (10.0 mg kg(-1) day(-l), for 21 days) diazepam treatment on carrageenin-induced paw edema were studied in rats. The results showed that acute treatment with high doses of diazepam decreased paw edema volume in a dose-dependent manner, and this effect was observed as early as 1 h after the administration of the 20.0 mg/kg dose and continued until the last measurement was performed (8 h). In contrast, long-term diazepam administration did not modify the phlogistic-induced edema. Taken together, these data show that 1) acute diazepam treatment with high doses decreases the volume of the acute inflammatory paw edema developed by the organism as a response to carrageenininduced injury, and 2) long-term diazepam treatment induces tolerance to this effect. These results are discussed in the light of a possible effect of diazepam on the components of the rat cellular and humoral immune/inflammatory reaction such as T lymphocytes and/or interleukins.

Effects of acute 2,4-dichlorophenoxyacetic acid intoxication on some rat serum components and enzyme activities

The present study was undertaken to investigate the effects of acute 2,4-dichlorophenoxacetic acid (2,4-D) intoxication (0.6 g/kg, po) on lactate dehydrogenase, alkaline phosphatase, aspartate amino-transferase, alanine aminotransferase, amylase, creatinine, glucose, total protein and albumin levels in rats. Serum levels of lactate dehydrogenase, alkaline phosphatase and creatinine increased from 1-to 4-fold at 5,8 and 24 h after 2,4-D administration, whereas serum levels of aspartate and alanine aminotransferase were higher only at 8 and 24 h. Amylase levels were only increased 8 h after administration of 2,4-D and then returned to normal levels. In contrast, 2,4-D reduced the serum levels of glucose and total protein 5,8 and 24 h and serum albumin levels 5 h after herbicide intoxication. Thus, acute intoxication with 2,4-D disrupts serum levels of several enzymes and components which are considered to be indicators of tissue injury. Most likely these alterations mainly reflect hepatic and muscle tissue damage induced by the herbicide, but significant pancreatic and kidney toxicity may also have occurred