Name: JOCIMAR JOSÉ PITOL
Publication date: 26/09/2024
Examining board:
Name |
Role |
|---|---|
| ALESSANDRA SIMAO PADILHA | Examinador Interno |
| STÊFANY BRUNO DE ASSIS CAU | Examinador Externo |
Summary: Cardiovascular diseases are a serious problem for human health, especially
myocardial ischemia. In this sense, research involving the coronary vascular bed have
great relevance. The function of blood vessels can be regulated by different hormones,
and progesterone is one of them, which can act on the coronary arteries through
different mechanisms. In addition, the direct action of these hormones can be
influenced by circulating hormones. Thus, studying the action of progesterone in a
model of hormone deficiency would be relevant to better understand its role on the
cardiovascular system, specifically in the coronary bed. Therefore, the study aims to
evaluate the reactivity to progesterone in the coronary bed of gonadectomized rats of
both sexes. For this purpose, gonadectomy and sham surgeries were performed on
Wistar rats (Rattus norvegicus) of both sexes, and after 15 days, progesterone was
administered in the coronary bed, in vitro, using the modified Langendorff method. The
results demonstrated that basal coronary perfusion pressure, was higher in Sham and
ovariectomized females when compared to males, however, gonadectomy was not
able to alter this parameter in either sex. The application of progesterone resulted in a
vasodilatory response in all groups, similarly between sexes and hormone deficiency.
After inhibition of nitric oxide pathway an increase in vasodilation occurred in
gonadectomized males and females. Notwithstanding, inhibition of prostanoids and
epoxyeicosatrienoic acids was not able to change the vasodilatory response to
progesterone. Classical progesterone receptor antagonism was able to significantly
reduce the vasodilatory response only in gonadectomized females. Thus, there is
evidence that sex and hormone deficiency do not affect progesterone vasodilation in
rat’s coronary bed.
