The incidence of coronary heart disease (CHD) in females is less than
males of the same age, suggesting a cardioprotective role for estrogen,
while the role of androgens in the development of CHD is controversial.
Men have estrogens in their tissues produced by aromatization of androgens
in the peripheral circulation but little is known about the possible
physiological role of this estrogen in males especially in CHD. This study
was designed to evaluate the effect of endogenous male estrogen on experimentally
induced myocardial infarction (MI) in male albino rats and
its possible relationship to the role of androgens. Fifty-four albino male
rats were used in this study. The rats aged 12 weeks and their average
weight was 200-250 gm. The animals were divided into 5 groups: Group
(1), consisted of 6 rats, served as a control group and was used for the
estimation of normal serum level of Creatirt kinase-MB (CK-MB). The other
4 groups (each consisted of 12 rats) were subjected to induction of MI using
a single intraperitoneal (Lp.) dose of isoprenaline. after being treated
according to one of four protocols of therapy. Group (2) was injected with
solvent. Group (3) received i.p. tamoxifen. an antiestrogen, in a dose of
mg/ kg/day for 3 days. Group (4) received a single i.p. dose (75 mg / kg) of
flutamide. (an anti-androgen). Group (4) was treated using both tamoxifen
and flutamide protocols. Induction of MI was carried out 24 hours after
the last dose of treatment. Thirty minutes after induction, the rats were
sacrificed, blood was collected and hearts were obtained for the estimation
of CK-MB and measurement of infarct size, as percentage of left ven-
23
Nasr A. Belacy et al...
title, respectively. The obtained results revealed that the enzyme CK-MB
was significantly higher in all groups subjected to MI than the control
group. Infarction size and CK-MB in group (3) were significantly more
than groups (2), (4) and (5) while in group (4) they were significantly less
than the other groups. Groups (2) and (5) showed no significant difference.
It could be concluded that endogenous estrogen may have a role in
cardioprotection in male rats and this role may be related to the role of
androgens. |
