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  1. Labetalol has non-selective α+β blocking activity. But β-adrenergic blocking is more potent than α-blocking activity.
  2. Serotonin is a monoamine neurotransmitter biochemically derived from the amino acid, tryptophan.
  3. Approximately 90% of the human body's total serotonin is located in the enterochromaffin cells in the alimentary canal (gut), and is used to regulate intestinal movements. The remainder is synthesized in serotonergic neurons of the CNS, where it has various functions including the regulation of mood, appetite, and sleep.
  4. Histamine causes the dilatation of small blood vessels but NOT of the large blood vessels.
  5. Fall in blood pressure caused by larger doses of histamine is treated with a combination of H1 and H2 antagonists.
  6. Mechanism by which body rejects transplanted organs is cell-mediated immunity, a type of acquired immunity.
  7. The antidote for clonidine poisoning is naloxone. It is also for the opiates poisoning.
  8. The classification of hypersensitivity reactions into four types is called as Coombs and Gell classification.
  9. There are four types of hypersensitivity reactions. Types I, Type II and Type III are mediated by antibodies, while Type IV is mediated by T cell lymphocytes.
  10. Morphine can directly release histamine from mast cells without involving antigen-antibody reaction.