The Role of Alpha Atrial Natriuretic Hormone in Pneumonectomy: An Experimental Study

Abstract

Objective: The alpha atrial natriuretic hormone (α-ANH) is released in response to atrial distension and excessive fluid volume in the body. The aim of the present study was to evaluate α-ANH levels before and after pneumonectomy and to investigate the effects of normal and increased volume of crystalloid–colloid fluids on α-ANH following pneumonectomy in a rabbit model. Methods: A total of 20 New Zealand rabbits were used in the study. The mean weight of the rabbits was 1.831 g. The subjects were divided into four groups with five in each group. The first group was given 3 mL/kg/h of crystalloid; the second group was given 10 mL/kg/h of crystalloid; the third group was given 3 mL/kg/h of colloid; the fourth group was given 10 mL/kg/h of colloid. Blood samples were preoperatively collected from the jugular vein. Posterolateral thoracotomy was applied to all subjects. The hilus was tied and cut en bloc with 2/0 silk, and pneumonectomy was performed. All groups received infusion for 3 h. Following infusion, blood samples from the contralateral jugular vein were collected at postoperative 3 h. Pre- and postoperative α-ANH levels were compared. Results: There was no significant difference in the mean weight of the groups (χ2=1.417, p=0.478). There was no significant difference in the pre- and postoperative α-ANH levels among all groups (Z=0.674, p=0.5 in the first; Z=0.405, p=0.686 in the second; Z=1.753, p=0.08 in the third; Z=0.944, p=0.345 in the fourth). Conclusion: Our study results suggest that pneumonectomy alone appears not to change the α-ANH levels, and hypoxia, increased atrial pressure, and some neurohormonal factors may enhance α-ANH release.

Keywords

• alpha atrial natriuretic hormone
• atrial natriuretic peptides
• pneumonectomy; postpneumonectomy pulmonary edema.