Quantitation of Ventricular Collagen in Male and Female Spontaneously Hypertensive Rats Using Hydroxyproline Analysis

Abstract

Hypertension, or chronically elevated blood pressure, can result in altered cardiac function and structure. The key structural alteration associated with hypertension is left ventricular hypertrophy. This increase in myocardial mass is based upon an increase in myocyte size and collagen deposition in the heart. Hydroxyproline, a nonessential amino acid, is found primarily in collagen. As a result, collagen content can be determined by measurement using a modification of Reddy and Enwemeka's hydroxyproline assay (1996). We tested the hypothesis that the ventricular collagen content in the hypertrophied ventricles of males is greater than in females. The results from the experiment demonstrate that there is a difference in the amount of cardiac collagen content between 18 month male and female spontaneously hypertensive rats (SHRs). The mean ± SEM for the cardiac collagen content in males was found to be 41.178 (± 11.872) μg collagen/mg weight wet ventricle (n=7) versus 30.196 (± 1.863) μg collagen/wet weight ventricle (n=7) in females.