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The influence of different estrus cycles on cardiac function following trauma‐hemorrhage: down‐regulation of cardiac IL‐6 and NF‐κB in the proestrus state
Author(s) -
Yang Shaolong,
Hsieh YaChing,
Hu Shunhua,
Choudhry Mashkoor A.,
Bland Kirby I.,
Chaudry Irshad H.
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a740
Subject(s) - estrous cycle , cardiac function curve , endocrinology , medicine , western blot , estrogen , chemistry , biology , andrology , heart failure , biochemistry , gene
To determine whether different estrus cycles influence cardiac function following trauma‐hemorrhage (T‐H), sham‐operation or T‐H was performed in five groups of female rats (BW 250–275 g) including di‐estrus (DE), pro‐estrus (PE), estrus (E), met‐estrus (ME), and ovariectemized (OVX) females (n=6‐7/group). Cardiac function was determined at 2 hour after T‐H and resuscitation. Cardiomyocytes were then isolated and neuclei were extracted. Cardiomyocyte IL‐6 protein levels and NF‐κ B were measured by western blot and cardiomyocyte NF‐κ B DNA binding activity was determined by EMSA. Moreover, plasma IL‐6, estradiol and progesterone were measure using ELISA or EIA kits. The results (one‐way ANOVA) indicated that: 1) cardiac function was depressed in DE, E, ME and OVX following T‐H, however, it was maintained in PE females; 2) the highest level of estrogen in the plasma was found in PE group; 3) plasma IL‐6 increased significantly in DE, E, ME and OVX after T‐H, however, the increase was attenuated in PE; 4) cardiomyocyte IL‐6 protein levels increased significantly in DE, E, ME and OVX after T‐H, however, it was attenuated in PE females; 5) cardiomyocyte NF‐κ B and NF‐κ B binding activity increased significantly after T‐H, however, they were attenuated in PE females. These data collectively lead us to conclude that the estrus cycle plays an important role on cardiac function following T‐H. The salutary effect seen in PE females following T‐H appears to be through NF‐κ B derived upregulation of cardiac IL‐6 pathway (NIH grant R37 GM 39519).