Relation between energy metabolism, glycolysis, noradrenaline release and duration of ischemia

We studied the effect of 12-36 min of global ischemia followed by 36 min of reperfusion in Langendorff perfused rabbit hearts (n = 26). Metabolism was determined in terms of peak and total release of purines (adenosine, inosine, hypoxanthine), lactate and noradrenaline during reperfusion; and myocardial content of nucleotides (ATP, ADP, AMP), glycogen and noradrenaline at the end of reperfusion. An inverse relationship (r = -0.79) existed between duration of ischemia and developed pressure post-ischemia. Early during reperfusion, after 12 min of ischemia, the purine concentration (peak release) increased 100x (p < 0.01), that of lactate and noradrenaline 10x (p < 0.05). Total purine release rose with progression of the ischemic period (30x after 36 min of ischemia; p < 0.01), concomitant with a reduction in nucleotide content. Lactate release was independent from the duration of ischemia, although glycogen had declined by 30\% (p < 0.01) after 36 min of ischemia. The acid insoluble glycogen fraction, which presumably contains proglycogen, increased substantially during short-term ischemia. Peak noradrenaline increased 100x, and 200x, (p < 0.05) after 24 and 36 min of ischemia, respectively. Total noradrenaline release due to various periods of ischemia mirrored its peak release. Function recovery was inversely related to total purine and noradrenaline efflux (both r = -0.81); it correlated with tissue nucleotide content (r = 0.84). In conclusion, larger amounts of noradrenaline are released only after a substantial drop in myocardial ATP. During severe ischemia ATP consumption more than limited ATP production by anaerobic glycolysis, is a key factor affecting recovery on subsequent reperfusion. In contrast to lactate efflux, purine and noradrenaline release are useful markers of ischemic and reperfusion damage

Anti-fibrotic effects of human amniotic membrane transplantation in established biliary fibrosis induced in rats

Liver fibrosis is characterized by excessive accumulation of extracellular matrix components in the liver parenchyma that distorts the normal architecture and hepatic function. Progressive fibrosis could end in the advanced stage know as cirrhosis, resulting in the need to resort to liver transplantation. Amniotic membrane (AM) has emerged as an innovative therapeutic approach for chronic liver diseases for its antiinflammatory, antiscarring, and wound-healing effects. We have recently shown that AM used as a patch onto the liver surface at the same time of fibrosis induction significantly reduces the progression and severity of biliary fibrosis. Here, we have investigated the effects of human AM on the already established liver fibrosis induced in rats by the bile duct ligation (BDL). We also explored the action of AM on the expression of the transforming growth factor (TGF)-\u3b21, the main profibrogenic factor in hepatic fibrosis, and the pro-inflammatory cytokines, tumor necrosis factor (TNF)-\u3b1, interleukin (IL)-6 and anti-inflammatory cytokine, IL-10. After 2 weeks from BDL, the liver was covered with a fragment of AM, or left untreated. Six weeks later, the fibrosis was first assessed by the semiquantitative Knodell and the METAVIR scoring systems and, thereafter, by the CellProfiler digital image analysis to quantify the area occupied by collagen deposition, ductular reaction, activated myofibroblasts, and TGF-\u3b21. The hepatic cytokines were determined by ELISA. AM-treated rats showed a significantly lower score compared to the control BDL rats (2.5 \ub1 0.9 versus 3.5 \ub1 0.3; p&lt;0.05), respectively. The collagen deposition, ductular reaction, number of activated myofibroblasts, and TGF-\uf0621 were all reduced to about 50% of levels observed in untreated BDL rats. These findings suggest that AM, when applied as a patch onto the liver surface is useful for treating well-established cholestatic fibrosis and the mechanism was partly by, means of downregulating the profibrotic factor TGF-\u3b21 and IL-6