The distribution of phosphofructokinase (PFK) in gray and white matter regions of the rat nervous system was evaluated. Determinations of PFK activity revealed that cell body enriched regions (sensorimotor cortex) had a significantly higher level of activity than axonal regions (sciatic nerve, dorsal roots, and optic nerve). The level of PFK activity was also significantly higher in central axons (optic nerve) than in peripheral axons (sciatic nerve). Differences in PFK activity could be largely attributed to differences in tissue content of the enzyme rather than to differences in the types of PFK isozymes present. Cortex contained significantly larger amounts of PFK relative to total protein than did peripheral nerve. However, purification of PFK revealed that all three of the PFK isozymes, C (86 kd), A (84 kd), and B (80 kd), were present in both cortex and sciatic nerve. Both SDS/PAGE and immunoblotting studies using PFK isozyme-specific antibodies demonstrated that the relative proportions of the three PFK isozymes were similar in cell body and axonal regions of the nervous system. The PFK-C and PFK-A isozymes each comprised about half the total and only small amounts of the PFK-B isozyme were present in both regions. However, immunoprecipitation experiments suggested that quantitatively different proportions of the possible PFK hybrids (tetramers) may be distributed between axonal and cell body regions. The transport of PFK was examined in this study and PFK was identified in slow component b (SCb) of axonal transport. SCb moves at a rate of 2-4 mm/day in rat axons and is known to contain several other enzymes of intermediary metabolism as well as actin. The finding that PFK, the rate limiting enzyme in glycolysis, is present in SCb lends support to the hypothesis that glycolytic enzymes are not freely diffusing proteins in axons but, instead, are present as organized assemblies that have long-term, yet flexible, associations with structural elements of the cytoplasm.
The wound healing process and production of
tumour necrosis factor alpha (TNF-α) by peritoneal
cells of 7-day and 14-day obstructive jaundice (OJ)
and sham-operated rats were investigated. In the
study the skin wound breaking strength was measured,
In addition such histological and biochemical
parameters as fibroblast and endothelial cell proliferation,
inflammatory cell infiltration and hydroxyproline
content were evaluated in polyurethane
sponge discs implanted subcutaneously into rats.
TNF-α production by peritoneal exudate cells (PEC),
both spontaneous and lipopolysaccharide (LPS)-
induced was determined by a bioassay. In OJ rats the
process of both early as well as late phase of healing
was impaired. The breaking strength of skin wound
was decreased, the fibroblast and endothelial cell
proliferation and collagen deposition, as well as hydroxyproline
content were diminished. In 7 day OJ
the numbers of inflammatory cells in the implants
were lowered with a subsequent slight increase on
day 14 of OJ. The spontaneous and LPS induced TNF-
α production by PEC were significantly higher in 7
day OJ as compared with sham-operated controls. On
day 14 of OJ the LPS-induced TNF-α level was, in
contrast, much lower and did not differ much from
the spontaneous TNF-α production. We conclude
that the impairment of wound healing in OJ results
from disturbances in functioning of the immune
system caused by systemic endotoxaemia.
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