CCK-PZ causes all of the following, except:

CCK-PZ causes all of the following, except:

A. Gall bladder contraction
B. Pancreatic enzyme secretion
C. Increased gastrin secretion
D. Decreased lower oesophageal sphincter contraction.

 Answer is C. Increased gastrin secretion.
  
Cholecystokinin (CCK-PZ) earlier called pancreozymin, is a peptide hormone of the gastrointestinal system responsible for the digestion of fat and protein. The literal meaning of the word cholecystokinin from its Greek origin is 'move the bile sac'.

• Synthesized by the I-cells in the mucosal epithelium of the small intestine and is secreted in the duodenum.
• It causes gall bladder contraction releasing bile from the gall bladder and hence obviates the first option.
• It also causes release of digestive enzymes from the pancreas obviating the second option.
  
•  Its recent use as a hunger suppressant in Western countries is well-known.
• Cholecystokinin inhibits the secretion of gastrin from antral G cells, an effect that is speculated to be mediated by D cells secreting somatostatin. Hence, there should be decreased gastrin secretion.
  
•  CCK also causes relaxation of the lower oesophageal sphincter by reducing its tone.