A Long - term Effect of Pentobarbital on the Atrial Natriuretic Peptide System in Rats / 대한마취과학회지

ABSTRACT

A long-term effect of pentobarbital on the atrial natriuretic peptide (ANP) system was investigated. The experimental group of rats (Sprague-Dawley, male) was one week previously treated with pentobarbital (50 mg/kg, intraperitoneal), and the control was an age-matched group of rats which had never been anesthetized. ANP reaponse to volume-expansion (VE) induced by intravenous infusion of iso-oncotic saline over 30 min (total volume infused amounted up to 5% body weight) was examined under thiopental anesthesia (50 mg/kg, intraperitoneal). Basal plasma ANP level did not significantly differ between the experimental and control groups. Following VE, while the plasma ANP five-fold increased in the control, it rather decreased in the experimental group. Despite the different ANP responses, the magnitude of urinary responses (volume and sodium excretion) to VE did not differ between the two groups. Right and left atrial tissue contents of ANP were significantly lower in the experimental group than in the controL In another series of experiments, the two-kidney, one clip rats were made under either pentobarbital or ether anesthesia and the blood pressure and ANP responses were compared. While the magnitude of blood pressure increases did not differ, the plasma ANP level measured on Day 12 after the clipping was lower in the pentobarbital group than in the ether group. These results suggest that pentobarbital has a long-term inhibitory effect on the ANP system. Its physiological significance in blood pressure and body fluid homeostasis remains to be determined.