Fractal analysis of cytoskeleton rearrangement in cardiac muscle during head-down tilt

Donald Thomason, Otis Anderson, Vandana Menon

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Head-down tilt by tail suspension of the rat produces a volume, but not pressure, load on the heart. One response of the heart is cytoskeleton rearrangement, a phenomenon commonly referred to as disruption. In these experiments, we used fractal analysis as a means to measure complexity of the microtubule structures at 8 and 18 h after imposition of head-down tilt. Microtubules in whole tissue cardiac myocytes were stained with fluorescein colchicine and were visualized by confocal microscopy. The fractal dimensions (D) of the structures were calculated by the dilation method, which involves successively dilating the outline perimeter of the microtubule structures and measuring the area enclosed. The head-down tilt resulted in a progressive decrease in D (decreased complexity) when measured at small dilations of the perimeter, but the maximum D (maximum complexity) of the microtubule structures did not change with treatment. Analysis of the fold change in complexity as a function of the dilation indicates an almost twofold decrease in microtubule complexity at small kernel dilations. This decrease in complexity is associated with a more Gaussian distribution of microtubule diameters, indicating a less structured microtubule cytoskeleton. We interpret these data as a microtubule rearrangement, rather than erosion, because total tubulin fluorescence was not different between groups. This conclusion is supported by F-actin fluorescence data indicating a dispersed structure without loss of actin.

Original languageEnglish (US)
Pages (from-to)1522-1527
Number of pages6
JournalJournal of applied physiology
Volume81
Issue number4
DOIs
StatePublished - Jan 1 1996

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Head-Down Tilt
Fractals
Cytoskeleton
Microtubules
Myocardium
Dilatation
Actins
Fluorescence
Hindlimb Suspension
Normal Distribution
Tubulin
Cardiac Myocytes
Confocal Microscopy
Pressure

All Science Journal Classification (ASJC) codes

  • Physiology
  • Physiology (medical)

Cite this

Fractal analysis of cytoskeleton rearrangement in cardiac muscle during head-down tilt. / Thomason, Donald; Anderson, Otis; Menon, Vandana.

In: Journal of applied physiology, Vol. 81, No. 4, 01.01.1996, p. 1522-1527.

Research output: Contribution to journalArticle

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