The structural proteins of normal and diseased human myocardium.

Abstract

SUMMARY Microanalytical techniques have been developed for the quantitative determination of actomyosinand collagen from 20 to 30-mg (wet mass) samples of myocardium. Actomyosin is the major contractile protein complex and is, therefore, an index of functional muscle; collagen is the major protein of connective and scar tissue and is, therefore, an index of fibrosis. These proteins were determined in six myocardial samples from each of four normal, four ischemic, and three hypertrophied human hearts. As determined by electrophoresis in a denaturing medium, the concentration of actomyosin in normal myocardium is 69 /tg/mg wet tissue; the concentration in ischemic myocardium is not significantly different from normal, but is approximately 45% higher than normal in hearts with left ventricular hypertrophy. These observations indicate that hypertrophy is not simply an increase in total heart mass but, rather, involves an increase in actomyosin concentration in myocardial tissue as well. Collagen is determined from amino acid analysis of whole tissue for 4-hydroxyproline, an amino acid characteristic of this protein; the concentration of collagen in normal (6.1 /ig/mg wet tissue) myocardium are not significantly different from those in hypertrophied myocardium. In focal regions of ischemic hearts, however, collagen is increased 2-to 4-fold. The concentration of collagen in myocardial tissue correlates well (r = 0.947) with the degree of fibrosis determined by conventional histological techniques. This work represents (1) a more direct biochemical determination of contractile protein concentration in whole myocardium and (2) a more direct correlation of the biochemical assay for collagen with histological data than have been reported previously.

Hydroxyproline and passive stiffness of pressure-induced hypertrophied kitten myocardium.

“…This would account for the differences in both stiffness and hydroxyproline concentrations between these models. Unfortunately, we do not have histologic confirmation of our hypothesis but others have observed a strong correlation between collagen concentration and histologic estimation of connective tissue (18). The study of Peterson et al (19) demonstrating normal stiffness of hypertrophied myocardium in patients with aortic stenosis, the preliminary observations of Serizawa et al (20) of normal stiffness in an experimental model of slowly developing pressure-induced hypertrophy and unchanged collagen concentration under the latter conditions (18,21) support our hypothesis regarding the interrelationship of loading conditions, the rapidity with which hypertrophy develops, myocardial fibrosis, and stiffness.…”

Zonal and meridional variations of eddy fluxes induced by long planetary waves

“…References to the literature may be found in Baines and Frederiksen ( 1 978) and Frederiksen (1978) (hereafter denoted F). Moreover, a major problem with flux parametrizations that are based on instability theory with basic flow profiles which are purely zonal is that, while they (approximately) describe correctly the meridional variations of the zonally averaged transports by the short-wave baroclinic eddies, they do not account properly for the quite considerable fluxes produced by long planetary waves (see, for example, Oort and Kasmusson 1971 ;Mak 1978;Tucker 1979).…”

Eocene palynomorphs from the black diamond mines regional preserve, contra costa county, California

“…al. (1971), Frederiksen (1978Frederiksen ( , 1980Frederiksen ( , 1983, and Wingate (1983). Stereisporites antiquasporites (Wilson & Webster 1946) Dettmann 1963 Plate 1, fig.…”