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Melatonin membrane MT2 receptor expression in left ventricular cardiac myocytes of female rats with chronic hypoestrogenism and heart failure (648.2)
Author(s) -
Liskova Yuliya,
Stadnikov Alexander,
Salikova Svetlana,
Klimushkin Alexey
Publication year - 2014
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.28.1_supplement.648.2
Subject(s) - hypoestrogenism , medicine , endocrinology , heart failure , menopause
This study was done in order to establish an expression pattern of the melatonin MT2 receptors (MT2R) in LV cardiac myocytes (CM) of female rats with hypoestrogenism and heart failure. Hypoestrogenism (hypo‐E) was induced by bilateral ovariectomy and heart failure (HF) was caused by s.c. injection of a 1% mezaton solution (0.1ml) followed by an intensive swimming regimen for 14 days. Thirty adult outbred female rats were used: 10 rats with a combination of hypo‐E and HF (hypo‐E/HF); 10 rats with HF only; 5 rats with hypo‐E only; and 5 intact rats served as a control. At the end of experiment, the MT2R immunoreactivity (MT2R‐IR) was detected by immunohistochemistry with an anti‐MTNR1B antibody. The localization and intensity of MT2R‐IR were assessed in a double‐blind manner on a semiquantitative rating scale using the following criteria: (‐) no MT2R‐IR; (+) slight MT2R‐IR, a few immunopositive CM; (++) moderate MT2R‐IR, more than 5 immunopositive CM on each section; (+++) high MT2R‐IR, almost all CM are immunopositive. We found that in control rats the CM showed a slight to moderate level of MT2R‐IR (+/++), while in HF the CM revealed the highest level of MT2R‐IR (+++). The reduced MT2R‐IR was observed in rats with hypo‐E only (+), whereas the animals from the hypo‐E/HF group showed the lowest level of MT2R‐IR (‐/+). Our findings demonstrate that chronic hypoestrogenism inhibits a cardioprotective increase in MT2R induced by HF.