Guinea pig pancreatic polypeptide: structure and pancreatic content

Area of Science:

• Endocrinology
• Comparative Physiology
• Biochemistry

Background:

• Pancreatic polypeptide (PP) is a hormone found in the pancreas.
• Guinea pigs (GP) have unique anatomical features, including the absence of a ventral pancreas.
• Understanding species-specific hormone content is crucial for comparative physiology.

Purpose of the Study:

• To purify and characterize guinea pig pancreatic polypeptide (PP).
• To compare the sequence of guinea pig PP with that of other species.
• To investigate the reasons for the observed PP content in guinea pig pancreata.

Main Methods:

• Purification of GP PP using three sequential High-Performance Liquid Chromatography (HPLC) steps from an acid-alcohol extract.
• Quantification of total PP and glucagon content per pancreas in guinea pigs and dogs.
• Comparative sequence analysis of GP PP against beef and human PP.

Main Results:

• Guinea pig PP was successfully purified.
• The sequence of GP PP was determined and compared to beef and human PP.
• A single guinea pig pancreas (2.4 g) contained 1.0 nmol PP and 61 nmol glucagon, while a dog pancreas (35 g) contained 385 nmol PP and 81 nmol glucagon.
• The low PP content in GP pancreas correlates with the absence of a ventral pancreas.

Conclusions:

• The purification and sequencing of guinea pig PP provide valuable comparative data.
• The anatomical peculiarity of the guinea pig (lacking a ventral pancreas) explains the lower pancreatic polypeptide content.
• The high glucagon content in guinea pig pancreas is consistent with previous findings.