Autocoids Flashcards
….. Are chemical mediators that are synthesized and function in a localized tissue or participate in physiological and pathophysiological response to injury
Autacoids
Autaciods are also called
Local hormones
Autaciods do not function as
Blood borne hormone
Autaciods are short lived and rapidly…..
Degraded
The three categories of autaciods are…
Biogenic amines
Polypeptides
Lipid derived autaciods
Lipid derived autaciods are… And…..
Eicosanoids
Platelet activating factor
Lipid derived autaciods are… And…..
Eicosanoids
Platelet activating factor
Diatery histidine is decarboxylated by…….. to form histamine
L-histidine decarboxylase
How many pathways are involved in the degradation of histamine
Two
The major degradation pathway >50% involves conversion of histamine to an inactive…..
L-methylhistamine by imidazole -N- methyltransferase
The minor pathway involves breakdown of histamine by…..
Diamond oxidase to form imidazoleacetic acid
Histamine is widely distributed in
Tissue
The primary tissue sites storing histamine are the
Lung, skin, mucosal layer and Basophils
Food and vegal stimulation can release histamine from the stomach…..
Enterochromaffin cells
Histamine in CNS acts as
Neurotransmitters
The rate of histamine synthesis and turnover in mast cells is…..
Low
What’s type 1 igE-mediated hypersensitivity reaction.
When sensitized mast cells or Basophile are coupled to igE antibodies and then exposed to the right proper antigens
H1 receptors are coupled to
Gq protein- PLc
