| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Kinesiology and Physical Education, Wilfrid Laurier University, and Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada N2L 3C5
The effects of estrogen and
ovariectomy on indexes of muscle damage after 2 h of complete
hindlimb ischemia and 2 h of reperfusion were investigated
in female Sprague-Dawley rats. The rats were assigned to one of three
experimental groups: ovariectomized with a 17
-estradiol pellet
implant (OE), ovariectomized with a placebo pellet implant (OP), or
control with intact ovaries (R). It was hypothesized that following
ischemia-reperfusion (I/R), muscle damage indexes [serum
creatine kinase (CK) activity, calpain-like activity, inflammatory cell
infiltration, and markers of lipid peroxidation
(thiobarbituric-reactive substances)] would be lower in the OE and R
rats compared with the OP rats due to the protective effects of
estrogen. Serum CK activity following I/R was greater (P < 0.01) in the R rats vs. OP rats and similar in
the OP and OE rats. Calpain-like activity was greatest in the R rats
(P < 0.01) and similar in the OP and OE rats.
Neutrophil infiltration was assessed using the myeloperoxidase (MPO)
assay and immunohistochemical staining for CD43-positive (CD43+) cells.
MPO activity was lower (P < 0.05) in the OE rats
compared with any other group and similar in the OP and R rats. The
number of CD43+ cells was greater (P < 0.01) in the OP
rats compared with the OE and R rats and similar in the OE and R rats.
The OE rats had lower (P < 0.05)
thiobarbituric-reactive substance content following I/R compared with
the R and OP rats. Indexes of muscle damage were consistently
attenuated in the OE rats but not in the R rats. A 10-fold difference
in serum estrogen content may mediate this. Surprisingly, serum CK
activity and muscle calpain-like activity were lower (P < 0.05) in the OP rats compared with the R rats. Increases in serum
insulin-like growth factor-1 content (P < 0.05) due to
ovariectomy were hypothesized to account for this finding. Thus both
ovariectomy and estrogen supplementation have differential effects on
indexes of I/R muscle damage.
inflammatory cells; myeloperoxidase; calpain; creatine kinase; skeletal muscle
This article has been cited by other articles:
|
|
 |
|
  C. M. Dieli-Conwright, T. M. Spektor, J. C. Rice, F. R. Sattler, and E. T. Schroeder Influence of hormone replacement therapy on eccentric exercise induced myogenic gene expression in postmenopausal women J Appl Physiol, November 1, 2009; 107(5): 1381 - 1388. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Bombardier, C. Vigna, S. Iqbal, P. M. Tiidus, and A. R. Tupling Effects of ovarian sex hormones and downhill running on fiber-type-specific HSP70 expression in rat soleus J Appl Physiol, June 1, 2009; 106(6): 2009 - 2015. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. L. Enns and P. M. Tiidus Estrogen influences satellite cell activation and proliferation following downhill running in rats J Appl Physiol, February 1, 2008; 104(2): 347 - 353. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W.-J. A. Tsai, K. M. McCormick, D. A. Brazeau, and G. A. Brazeau Estrogen Effects on Skeletal Muscle Insulin-Like Growth Factor 1 and Myostatin in Ovariectomized Rats Experimental Biology and Medicine, November 1, 2007; 232(10): 1314 - 1325. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P M Tiidus Can oestrogen influence skeletal muscle damage, inflammation, and repair? Br. J. Sports Med., May 1, 2005; 39(5): 251 - 253. [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Xu, S. J. Armstrong, I. A. Arenas, D. J. Pehowich, and S. T. Davidge Cardioprotection by chronic estrogen or superoxide dismutase mimetic treatment in the aged female rat Am J Physiol Heart Circ Physiol, July 1, 2004; 287(1): H165 - H171. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Xing, A. Miller, L. Novak, R. Rocha, Y.-F. Chen, and S. Oparil Estradiol and Progestins Differentially Modulate Leukocyte Infiltration After Vascular Injury Circulation, January 20, 2004; 109(2): 234 - 241. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
