[Effects of intravenous anesthetics and analgesics on plasma alpha-rat atrial natriuretic peptide (alpha-rANP) levels in rats].

Effects of various intravenous anesthetics and analgesics on alpha-rat atrial natriuretic peptide (alpha-rANP) concentrations in the plasma were studied in unrestrained rats. Morphine (30 mg.kg-1), fentanyl (0.2mg.kg-1) and buprenorphine (1mg.kg-1) produced 10-, 10- and 3.3-fold significant increases in plasma alpha-rANP over control group at 20min after intraperitoneal injections of each drug, respectively. A marked increase in plasma alpha-rANP after morphine administration was still observed at 60min, but those after fentanyl and buprenorphine were reduced to 4.7-from 10.0-fold and 1.6-from 3.3-fold increase at 60min, respectively. Pentazocine (40mg.kg-1) significantly increased plasma alpha-rANP to 1.3 times higher than that of control group only at 60 min, while ketamine (40mg.kg-1) caused an insignificant increase in plasma alpha-rANP to 1.4 and 1.3 times at 40 and 60 min. Droperidol (10mg.kg-1) tended to decrease plasma alpha-rANP and a significant reduction was observed at 60 min. Propofol (40mg.kg-1) did not affect on plasma alpha-rANP. Pentobarbital (50mg.kg-1) produced an insignificant fall in plasma alpha-rANP. Plasma levels of ACTH, compB and aldosterone increased after injections of morphine and fentanyl. These results indicate that mu-type opiate receptor plays an important role in secreting alpha-rANP and activating pituitary-adrenal axis in the rats.