Altered AMP deaminase activity may extend postmortem glycolysis.

Area of Science:

• Muscle energy metabolism
• Postmortem biochemical changes
• Pork quality

Background:

• Postmortem energy metabolism leads to hydrogen accumulation and stable ultimate pH in muscle.
• Extended glycolysis can negatively impact pork quality.
• Increased adenonucleotide availability postmortem may prolong glycolysis.

Purpose of the Study:

• To investigate if reducing AMP deaminase activity can extend postmortem glycolysis and lower muscle ultimate pH.
• To explore the role of AMP deaminase abundance and activity in RN⁻ pigs, known for low ultimate pH pork.

Main Methods:

• Utilized an in vitro system mimicking postmortem glycolysis using Longissimus muscle samples.
• Administered pentostatin, an AMP deaminase inhibitor, to assess its effects on glycolysis.
• Compared AMP deaminase abundance and activity in muscle from RN⁻ pigs versus wild-type.

Main Results:

• Pentostatin treatment significantly lowered ultimate pH and increased lactate and glucose 6-phosphate levels over time.
• AMP deaminase abundance and activity were found to be lower in RN⁻ muscle compared to wild-type muscle.
• Altering adenonucleotide availability postmortem effectively extended the postmortem pH decline.

Conclusions:

• Reducing AMP deaminase activity can extend postmortem glycolysis and lower ultimate pH.
• AMP deaminase activity plays a role in the low ultimate pH characteristic of RN⁻ pork.
• Modulating adenonucleotide metabolism offers a potential strategy to influence pork quality.