Energy metabolism during cutaneous wound healing in immunocompromised and aged rats

Cutaneous cells primarily depend upon carbohydrate metabolism for their energy requirement during healing process. But, it may be greatly hampered during various pathological and altered physiological conditions. The present study was therefore undertaken to investigate the intermediate steps of energy metabolism by measuring enzyme activities in the granulation tissues of immunocompromised and aged rats following excision-type of cutaneous injury. The activities of key regulatory enzymes hexokinase (HK), phosphofructokinase (PFK), lactate dehydrogenase (LDH), citrate synthase (CS) and glucose-6 phosphate dehydrogenase (G6PD) have been monitored in the wound tissues of immunocompromised and aged rats at different time intervals (2, 7, 14 and 21 days) of postwounding. The activities of HK and CS were found significantly decreased both in immunocompromised and aged rats as compared to control subjects. However G6PD exhibited an elevated activity at early stage followed by a decreased activity at later phase of healing both in immunocompromised and aged rats. The PFK and LDH demonstrated an upward trend in immunocompromised rats but a decreasing trend in aged rats. Thus, the results suggest that significant alterations in the activities of energy metabolizing enzymes in the granulation tissues in both immunocompromised as well as in aged rats may overall affect the energy availability for cellular activity needed for repair process. Hence, this may perhaps be one of the factor responsible for impaired healing in these subjects.