Glycosaminoglycans, intervertebral disks and exercise

[Guest guest]

Members may be interested in the following studies, esp. those of us

getting older and creakier.

Study 1: Since increases are transient, it is hard to know what the

practical implications are, but interesting nevertheless:

Alberto Calatroni; Avenoso; Alida M. Ferlazzo; Arno Lindner;

Giuseppe M. Campo. Transient Increase with Strenuous Exercise of

Plasma Levels of Glycosaminoglycans in Humans and Horses. Connective

Tissue Research, Volume 49, Issue 6 November 2008 , pages 416 - 425

Abstract

Plasma glycosaminoglycans (GAGs) were isolated and purified by

chromatographic procedures in healthy humans and horses before and

after physical exercise. A weak anion exchange resin was used to

separate polyanions. Humans exercised on a cycloergometer, while

horses were exercised on a treadmill and in show jumping competition.

Some GAGs were isolated from untreated plasma and operationally

defined as native proteoglycans (PGs), while the total GAG amount was

isolated from mild alkali treated plasma. Plasma GAG concentrations in

terms of galactosamine and galactose, the respective components of the

cartilage polysaccharides chondroitin sulphate and keratan sulphate,

significantly increased only when the subject was exercised

intensively, in both humans and horses. Only native PGs fraction

contributed to GAG levels changes. The increases were transient, since

preexercise values were reached in 30 min in horses. These changes

with exercise are suggested to be a tool to measure the effect of

physical exercise on cartilage PG metabolism.

http://www.informaworld.com/openurl?genre=article & issn=0300-8207 & volume=49 & issue\

=6 & spage=416

Study 2, relevant to recent discussions about LBP:

Maosheng Xia; Yue Zhu. Expression of Integrin Subunits in the

Herniated Intervertebral Disc

Connective Tissue Research, Volume 49, Issue 6 November 2008 , pages 464 - 469

Abstract

Integrins are a class of cell adhesion molecules that regulate

interactions between cells and their extracellular matrix (ECM).

Several specific integrin receptors have been indentified in

intervertebral discs, including the fibronectin-binding integrin

receptors agr5 â1, agrv â3 and the collagen-binding integrin receptors

agr1 â1, agr2 â1, and, agrv â1. But the integrins expressions in

degenerated intervertebral discs are still unknown. In our study, the

expressions of agr1, agr2, agr5, agrv, â1, â3 integrin subunits,

collagens, and fibronectin in normal and herniated intervertebral

discs of human were determined. Specimens of human lumbar

intervertebral discs were divided into 3 groups: normal discs (n =

10), protrusion (n = 15), and extrusion (n = 15). Real-time

quantitative reverse transcription polymerase chain reaction (RT-PCR)

and immunoprecipitation were used to evaluate the agr1, agr2,

agr5,agrv, â1, and â3 integrin subunits messenger ribonucleic acid

(mRNA) and protein expressions. RT-PCR was also performed to measure

the mRNA level of collagen I, collagen II, and fibronectin. The

expressions of agr5 and â1 subunits were increased in herniated discs,

especially in the discs of extrusion. But as to agr1, agr2, agrv and

â3, their expressions had no difference among the discs. Fibronectin,

whose binding integrin receptor was agr5 â1 was also increased. And in

herniated discs, the collagen I was increased, but the collagen II was

decreased. The expressions of some integrin subunits were increased in

herniated discs. These results may be attributed to the interaction

between cells and the ECM in the process of degeneration.

http://www.informaworld.com/openurl?genre=article & issn=0300-8207 & volume=49 & issue\

=6 & spage=464

Krista

Toronto, ON

--------------------

Krista -Dixon, PhD

Editor-in-Chief, Spezzatino

Research Director, Healthy Food Bank

www.spezzatino.com

www.healthyfoodbank.com

krista@...

x707