ABSTRACT
Background: Given the increasing use of waterpipe tobacco smoking in the world and its unknown effects on bone healing, this study investigated the repairing of femoral bone fractures in rats exposed to waterpipe tobacco smoking (WTS). Main Methods: This study involved 40 male Wistar rats that were divided into two groups, including the femoral fracture (Fx) and the Fx + WTS groups. Each group was divided into two subgroups that were evaluated for bone healing 28 and 42 days after femoral fracture. After fixing the fractured femur, the healing process was evaluated by radiography, pathological indicators, and a measurement of the blood levels of vascular endothelial growth factor (VEGF), parathyroid hormone (PTH), Ca ++, transforming growth factor-beta (TGF-ß), and insulin-like growth factor 1 (IGF-1). Additionally, the density of VEGF and CD34 in fracture tissue was investigated by immunohistochemistry. Key Findings: Radiographic findings showed that factors related to the earlier stages of bone healing had higher scores in the Fx + WTS28 and 42 subgroups in comparison to the Fx groups. The density of VEGF and CD34 showed that the angiogenesis processes were different in the bone fracture area and callus tissue in the Fx +WTS subgroups. The serum levels of VEGF, TGF-ß, and IGF-1 were significantly lower in the Fx +WTS42 group, and PTH in the Fx +WTS28 group was higher than that in the other groups. Significance: The findings showed the disturbance and delay in the femoral fracture union in rats exposed to hookah smoke. This is partly due to the reduction of molecular stimuli of bone synthesis and the attenuation of quantitative angiogenesis.
ABSTRACT
Ischemia/reperfusion (I/R) is a major cause of acute kidney injury. Several studies have shown that renin angiotensin (Ang) system and activation of Ang II type 1 receptor (AT1) are involved in various forms of kidney diseases. Likewise, Ang 1-7 as a physiologic antagonist of AT1 and losartan could possibly protect the kidney against I/R damage. Therefore, we investigated renal injury by administering the drugs before and after I/R. Fifty-four male Wistar rats were randomly assigned to five groups as follows. 1, Sham operated; 2, saline group (as a control group); 3, losartan group; 4, Ang 1-7group; and 5, Ang 1-7 + losartan simultaneously. It should be noted that groups 2-5 consisted of two separate I/R-induced subgroups both receiving medication where the first groups received the treatment 15 min before induction of I/R while the medications were given to the second groups immediately after induction of I/R. Twenty four h after I/R, blood samples were collected, and then levels of serum urea nitrogen (BUN), creatinine (Cr), nitrite, malondialdehyde (MDA), lactate dehydrogenase (LDH) and total antioxidant capacity (TAC) were measured. Likewise, nitrite, MDA and TAC were measured in the homogenized kidney tissues. After the induction of I/R, the BUN, Cr, LDH, and kidney tissue damage score increased. Administration of Ang 1-7 alone or simultaneously with losartan decreased the levels of aforementioned factors. Also, kidney MDA and nitrate levels significantly increased after I/R induction (P < 0.05). According to the results of this study, it can be claimed that the effect of losartan in the presence of Mas receptor is statistically significant and kidney damage dramatically decreases.