title: The Effect of Aerobic Exercise Training on Plasma Apelin Levels and Pain Threshold in T1DM Rats.
abstract: BACKGROUND
  Diabetes mellitus (types 1 and 2) leads to secondary complications such as neuropathy, which reduce a patient's quality of life. Apelin and its receptor, APJ, have been shown to have antinociceptive effects and to decrease blood glucose levels.
  
  
  OBJECTIVE
  The present experimental study was conducted in Iran and investigated the role of apelin, which is used to manage type 1 diabetes mellitus, during exercise training.
  
  
  METHODS
  Male Wistar rats (n = 36) were assigned by simple random allocation to six groups (n = 6): non-diabetic (ND), diabetic (D), sedentary non-diabetic (SND), sedentary diabetic (SD), exercise non-diabetic (END), and exercise diabetic (ED). Diabetes was induced by a single subcutaneous injection of streptozotocin (50 mg/kg). Exercise training consisted of treadmill running 60 minutes/day × 5 days/week for 10 weeks. The tail-flick test was used to assess the thermal pain threshold, and an apelin enzyme immunoassay kit was utilized to assess plasma apelin levels.
  
  
  RESULTS
  Plasma apelin level was higher (0.3 vs. 0.1, P < 0.0001) and the tail-flick latency was lower (2.2 vs. 3.8, P < 0.0001) in the D group than in the ND group. After the training program, plasma apelin levels decreased in the exercise groups, and the tail-flick latency increased in the ED group. No correlation was found between apelin blood concentrations and tail-flick latency following the training program in the ED group.
  
  
  CONCLUSIONS
  These findings suggest that apelin does not play any significant role in regulating the pain threshold in type 1 diabetes mellitus during exercise training.
authors.affiliation: Exercise Physiology Department, Faculty of Physical Education and Sport Sciences, Bu-Ali Sina University, Hamadan, IR Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Delavar
authors.affiliation: Exercise Physiology Department, Faculty of Physical Education and Sport Sciences, Bu-Ali Sina University, Hamadan, IR Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Heidarianpour
keywords: Apelin Protein; Exercise; Pain Threshold; Rat; Type 1 Diabetes Mellitus