Liver specific pyruvate kinase in pheasants Phasianus colchicus.

Area of Science:

• Biochemistry
• Enzymology
• Comparative Physiology

Background:

• The existence of a liver form of pyruvate kinase (a key glycolytic enzyme) in chickens is debated.
• Pyruvate kinase isozymes play crucial roles in cellular metabolism, with distinct forms found in different tissues.

Purpose of the Study:

• To investigate the electrophoretic and functional characteristics of pyruvate kinase isozymes in avian species, specifically pheasants, murres, and puffins.
• To determine if a distinct liver form of pyruvate kinase exists in these birds and to compare it with isozymes from other tissues.

Main Methods:

• Electrophoretic separation of pyruvate kinase isozymes from various tissues (liver, muscle, brain, kidney, lung, small intestine) of pheasants, murres, and puffins.
• Functional characterization of identified pyruvate kinase isozymes, particularly distinguishing between lung and muscle forms in pheasants.

Main Results:

• The liver form of pyruvate kinase in pheasants, murres, and puffins was found to be electrophoretically distinct from isozymes in muscle, brain, kidney, lung, and small intestine.
• While electrophoretic separation of lung, muscle, heart, brain, and small intestine isozymes was challenging, functional analysis confirmed distinct K (lung) and M (muscle) isozymes in pheasants.
• The study identified at least three distinct pyruvate kinase isozymes in these avian species.

Conclusions:

• Avian species like pheasants, murres, and puffins possess distinct liver pyruvate kinase isozymes.
• Functional and electrophoretic data support the classification of avian pyruvate kinase isozymes, including K and M forms.
• These findings contribute to understanding the diversity and tissue-specific roles of pyruvate kinase in birds.