ABSTRACT
Aging is associated with a progressive decline of plasma levels of dehydroepiandrosterone [DHEA] and dehydroepiandrosterone sulfate [DHEAS]. The present work studied the effect of DHEAS administration on the age related histological changes in the myocardium of the heart [being implicated in increased death rate from cardiovascular diseases in the elderly] and in the adrenal zona reticularis [being the major source of DHEA and DHEAS secretion]. Thirty male albino rats were divided into three groups; ten animals each. Group I was the control adult group [6-months age], group II was the control aged group [24-months age], and group III was the treated aged group [24-months age] that received DHEAS orally in a dose of 0.05 mg/rat/day for one month. Specimens from the left ventricle of the heart and from the suprarenal gland were taken from all groups and prepared for light and electron microscopic examination. In control aged group, the myocardium exhibited disorganization of cardiac myocytes and an increase in collagen fibers. Many cardiac myocytes had deeply stained nuclei with increased heterochromatin. Their sarcoplasm showed variable staining intensity, ill defined cross striations, marked degeneration of the mitochondria and increased intermyofibrillar spaces. Other cardiac myocytes appeared relatively with more or less normal light and electron microscopic structure. The cells of adrenal zona reticularis of control aged animals showed irregularity and deeply stained nuclei, in addition to decreased frequency of mitochondria and accumulation of lipid droplets in their cytoplasm. After DHEAS administration, there was a marked reduction in the age related histological changes of both the myocardium and adrenal zona reticularis. The myocardium of DHEAS treated aged animals showed regular arrangement of cardiac myocytes with comparative decrease in appearance of collagen fibers compared to the control aged group. Many cardiac myocytes had relatively normal appearance of their nuclei and sarcoplasm with prominent cross striations, regular organization of myofibrils and less degenerative changes in the mitochondria compared to those of the control aged group. Most zona reticularis cells of DHEAS treated animals had rounded nuclei and relatively normal appearance of their cytoplasm with increased frequency of mitochondria and decreased content of lipid compared to those of the control aged group. The mechanism of action of DHEAS as an antiaging steroid has been discussed. The preventive effect of DHEAS against age related structural changes [although incomplete prevention] is promising of its use as replacement therapy in elderly people to prevent, delay or attenuate the cardiac disorders which accompany aging and to improve the enzymatic activities and endocrine function of adrenal zona reticularis, thus, promote improvement of health with aging