Each year, nearly 250,000 women will die of coronary heart disease, the leading cause of death for women in America. A major contributing factor to coronary heart disease is the onset of hypertension, or high blood pressure. Hypertension is characterized as pertaining to a blood pressure of 140/90 mmHg or greater, 90-95% cases of which have no directly identifiable cause. It has been estimated that 6% of the world's deaths can be attributed to the effects of hypertension; these effects are systemic, and include damage to the brain, blood vessels, heart and kidneys. Most of these effects, however, often occur before the symptoms of hypertension actually arise, including arterial lesions of the brain, heart and kidneys, hyperinsulinemia, dyslipidemia, and elevated hematocrit levels. Much valuable research has been conducted in the past pertaining to hypertension, but with a deficiency in the area of gender studies with most research being performed exclusively on male test subjects. The present study simultaneously compares the effects of hypertension on both male, female, and ovariectomized female subjects, using the Spontaneously Hypertensive Rat (SHR) as a model. Collagen, which is the main focus of this study and the major ultrastructural protein in the heart, is quantitated using 2D-PAGE to analyze the differences in collagen density in male and female SHR hearts. It is our hypothesis that given the difference between male and female physiology, specifically the presence or absence of estrogen, that hypertensive effects will manifest differently between the sexes, in terms of collagen deposition and density in the cardiac architecture.