---

Background: There is an association between life style and serum levels of certain enzymes. This study aims to determine the effects of waterpipe smoke and darkness stress on serum levels of creatine kinase and alkaline phosphatase in female rats.
 Materials and methods: In this experimental study, female Wistar rats were randomly divided into control, waterpipe smoke receiving, under darkness stress and both under darkness stress and warerpipe smoke receiving groups of 7 rats in each. Waterpipe smoke receiving rats were exposed to waterpipe smoke for 100 min/day and animals under darkness stress exposed to 5 hours darkness during the day. Under darkness stress and warerpipe smoke receiving animals were exposed to both waterpipe smoke for 100 min/day and 5 hours darkness during the day. After 7 weeks, blood samples were collected and serum alkaline phosphatase and creatine kinase levels were measured by spectrophotometry. The data were analysed using ANOVA.
Results: The serum creatine kinase and alkaline phosphatase levels significantly increased in waterpipe smoke receiving, under darkness stress and both under darkness stress and waterpipe smoke receiving rats compared to control animals (p<0.001 and p<0.05, respectively). Also there was significant difference in creatine kinase and alkaline phosphatase levels between waterpipe smoke receiving and under darkness stress rats (p<0.001 and p<0.05, respectively). The serum levels of creatine kinase and alkaline phosphatase were significantly higher in waterpipe smoke receving rats compared to under darkness stress animlas (p<0.001and p<0.05, respectively).
 Conclusion: Our findings indicated that waterpipe smoke and darkness stress lead to increased serum levels of creatine kinase and alkaline phosphatase according to which, these factors can impose serious pathophysiological effects on internal organs including heart, brain, liver or muscles.