Pretreatment with calcitonin gene-related peptide attenuates hepatic ischemia/reperfusion injury in rats.
OBJECTIVE
Oxygen free radicals and apoptosis play important roles in liver ischemia/reperfusion (I/R) injury. We sought to investigate the protective effect of calcitonin gene-related peptide (CGRP) to attenuate liver I/R injury due to oxygen free radicals and apoptosis.


METHODS
Harvested rat livers were perfused via the portal vein with 60 mL of 4 degrees C histidine-tryptophan-ketoglutarate (HTK) solution alone in the control group, or with the same solution containing CGRP (3 microg/10 g body weight) in the experimental group. After 24 hours of cold storage, hepatic enzyme leakage, portal venous pressure, oxygen consumption, total adenine nucleotides (TAN), bile production, lipoperoxide (LPO) release, apoptosis, and histochemical changes were evaluated upon 45 minutes of isolated reperfusion.


RESULTS
Compared with control livers, CGRP-treated organs showed significantly decreased alanine aminotransferase (ALT) and glutamate-lactate dehydrogenase (GLDH) leakage and portal venous pressure (2.0 +/- 0.3 vs 4.0 +/- 0.4 mmHg; P < .01), with significantly increased bile production (8.56 +/- 0.76 vs 3.34 +/- 0.68 microL/g/45 min; P < .01), oxygen consumption (5.14 +/- 0.4 vs 2.57 +/- 0.2 microL/g/min; P < .01), and total adenine nucleotides (TAN) (11.1 +/- 0.71 vs 7.02 +/- 0.53 micromol/g; P < .01) upon reperfusion as signs of recovered viability. We observed infrequent positive terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labeling (TUNEL) staining, especially in sinusoidal lining cells (SLC). The percentage of TUNEL-positive cells in the CGRP group was significantly decreased compared with the control group: (4.1 +/- 0.67 vs 8.0 +/- 1.27; P < .05). Perfusate levels of low molecular weight (LMW) histone-associated DNA fragments (0.36 +/- 0.04 vs 0.53 +/- 0.06 AU; P < .05) were also decreased, coupled with strong 5'-nucleotidase (5'-NT) and LDH activity staining concentrated on the endothelial cells. LPO release in the perfusate was largely decreased: (0.12 +/- 0.02 vs 0.36 +/- 0.04 nmoL/g, P < .01).


CONCLUSIONS
CGRP ameliorated liver I/R injury due to reactive oxygen species and apoptosis.
Song
S W
SW
Department of General Surgery, First Affiliated Hospital, China Medical University, Shenyang, Liaoning, China. songsw10@hotmail.com
Guo
K J
KJ
Shi
R
R
Cheng
Y
Y
Liu
Y F
YF
D000227:Adenine Nucleotides / Q000378:metabolism*; D000410:Alanine Transaminase / Q000378:metabolism; D000818:Animals; D001646:Bile / Q000378:metabolism; D001794:Blood Pressure; D015740:Calcitonin Gene-Related Peptide / Q000627:therapeutic use*; D016923:Cell Death / Q000187:drug effects; D005947:Glucose; D020287:In Situ Nick-End Labeling; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000502:physiology; D008102:Liver Circulation / Q000187:drug effects*; D008297:Male; D008353:Mannitol; D019188:Organ Preservation Solutions; D010101:Oxygen Consumption / Q000187:drug effects; D011169:Portal Vein; D011189:Potassium Chloride; D011343:Procaine; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000517:prevention & control*
D000227:Adenine Nucleotides; C039984:Bretschneider cardioplegic solution; D019188:Organ Preservation Solutions; D008353:Mannitol; D011343:Procaine; D011189:Potassium Chloride; D000410:Alanine Transaminase; D005947:Glucose; D015740:Calcitonin Gene-Related Peptide