Metoprolol reduces cerebral tissue oxygen tension after acute hemodilution in rats.

Background: Perioperative beta-blockade and anemia are independent predictors of increased stroke and mortality by undefined mechanisms. This study investigated the effect of beta-blockade on cerebral tissue oxygen delivery in an experimental model of blood loss and fluid resuscitation (hemodilution).

Methods: Anesthetized rats were treated with metoprolol (3 mg x kg) or saline before undergoing hemodilution with pentastarch (1:1 blood volume exchange, 30 ml x kg).

Antidepressant-associated mood elevations in bipolar II disorder compared with bipolar I disorder and major depressive disorder: a systematic review and meta-analysis.

Objective: Antidepressant-associated manic and hypomanic episodes have been reported in bipolar I disorder but are rare in major depressive disorder (MDD). Several lines of evidence suggest that bipolar II disorder is a distinct illness from bipolar I disorder and MDD. The risk of antidepressant-associated mood elevations (AAME) in bipolar II disorder relative to bipolar I disorder and MDD is unknown.