ASYMMETRICAL REGULATION OF BLOOD-PRESSURE IN THE RAT MEDULLA

The effects of microinjection of serotonin-1 (5-HT1) antagonist methio thepin and 5-HT1 agonist buspirone into the nucleus reticularis parvoc ellularis were investigated in the anaesthetized rats. Methiothepin pr oduced an increase in arterial blood pressure when injected into the l eft side, but it did a decrease when injected into the right side. On the contrary, buspirone produced a decrease in arterial blood pressure when injected into the left side, but it did an increase when injecte d into the right side. These findings provide the clue to clarify that there is a reciprocal regulation of arterial blood pressure between t he left and right sides in the rat medulla. (C) 1997 Elsevier Science B.V.