Thread: Vantage points
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Old 01-07-2013, 10:33 AM   #251
sorokod
Join Date: Sep 2008
Posts: 582
United Kingdom
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Re: Vantage points

Perhaps the following is the most relevant to the current discussion. The source is the FAQ for Fascia Research Group (Division of Neurophysiology, of Ulm University, Germany) website at http://www.fasciaresearch.de

Quote:
Q. Can fascia contract on its own, independently from adjacent skeletal muscle fibers?

A. If one includes long term tissue contractures (like Morbus Dupuytren, Palmar Fibromatosis, etc.) within the realm of that question, then the answer is a clear yes. The work of Tomasek et al. strongly suggests that incremental summation of active cellular contractions plays a substantial role in such tissue contractures. The suspected contractile cells are fibroblasts or myofibroblasts.

In our own research, we performed an immunohistochemical examination for the presence of myofibroblasts in lumbar fascia, plantar fascia and Fascia lata from human donors. (For this we used the presence of alpha-smooth muscle actin containing stress fiber bundles as a marker for myofibroblasts, after subtracting those bundles which are associated with vascular vessels). We found such cells in all examined fascial tissues. We also observed a large inter-individual as well as intra-individual variance regarding the density of those fiber bundles, as well as indications for an increased density in perimysial tissues.

In addition we conducted mechanographic examinations of rat lumbar fascia in an organ bath environment for a potential contractile reaction in response to stimulation with different pharmacological agents. We were able to induce a clear contractile response in a significant number of fascia specimens in response to either the thromboxane analogue U46619, fetal calf serum (FCS) or high dosages of mepyramine. While not all samples responded to such stimulation, retrospective tissue analysis revealed a higher density of alpha smooth muscle actin containing stress fiber bundles in responder tissues compared with the non responding ones. Samples pretreated with the cell disrupting substance cytochalasin-D showed insignificant responses only. Neither adrenaline (epinephrin), acetylcholin, caffeine, angiotensine nor adenosine triggered any contractile responses. Currently we are examining samples pretreated with a a specific thromboxane receptor antagonist for their response to U46619 and also samples pretreated with a Rho-kinase inhibitor substance for their responses to U46619, FCS and mepyramine. Here we have not found any contractile response so far. Maximum force response in successful contraction tests usually occurs 15-45 minutes after substance addition; and seems to reverse when the stimulatory agent is removed.

Based on these findings, we are currently convinced that - at least in some samples of rat lumbar fascia, and within the in vitro conditions used in our examinations - fascia can actively contract within a time frame of minutes and that the presence of intrafascial myofibroblasts seems to be responsible for that capacity. We also performed a hypothetical calculation of the potential contractile force (applied to the paraspinal fasciae of the human lumbar area, based on the histological density values of our human fasciae examinations or alternatively on the measured contractile forces in our in vitro examinations with rat fascia). The resulting force values (of approx. 5 N for the whole lumbar are) were strong enough to predict a potential impact on normal musculoskeletal behavior, such as in gamma motor regulation. Yet they are far below the force quantities of skeletal musculature (and are not sufficient to e.g. move a limb in space in a matter of several seconds).
http://www.fasciaresearch.de/index.php/faq#Q2

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