Biochemical changes after surgical stress in rabbits

Area of Science:

• Biochemistry
• Endocrinology
• Physiology

Background:

• Surgical stress induces significant physiological and biochemical alterations.
• Understanding these changes in both normal and diabetic states is crucial for managing patient outcomes.
• Bessman's two-phase theory of stress response provides a framework for interpreting these metabolic shifts.

Purpose of the Study:

• To investigate and compare the biochemical responses to surgical stress in normal and diabetic rabbits.
• To analyze these responses across acute and subacute phases post-surgery.
• To evaluate the role of insulin in modulating these stress-induced metabolic changes.

Main Methods:

• Normal and diabetic rabbits were subjected to laparotomy under anesthesia.
• Blood samples were collected to measure glucose, ketone bodies, lactate, protein, blood urea nitrogen (BUN), and free alanine.
• Animals were studied in two phases: acute (0-180 minutes) and subacute (1-3 days post-surgery).

Main Results:

• Diabetic rabbits exhibited higher glucose, ketones, lactate, BUN, and alanine, with lower protein levels compared to normal rabbits.
• In the acute phase, both groups showed similar responses to surgical stress.
• In the subacute phase, normal rabbits showed increased ketone bodies and BUN, while diabetics displayed increased glucose, lactate, and alanine.

Conclusions:

• The observed biochemical changes support Bessman's two-phase stress response model (catecholamine and pituitary-adrenal phases).
• Acute phase response is attributed to glycogenolysis and lipolysis (catecholamine-mediated).
• Subacute phase response involves ketogenesis and gluconeogenesis from protein, with ketonemia prominent in normal rabbits, suggesting insulin's limited direct role in stress-induced lipolysis and ketogenesis.