Viktig bekreftelse på at blodsirkulasjon hemmes i betente ledd og at dette er noe av utgangspunktet for slitasjeskader siden vevet og skjelettet ikke får de næringsstoffene de trenger. Viktig studie å se på men vanskelig å copy-paste sitater…
«These vasoactive responses were completely abolished in the chronically inflamed knee joint, the abolition persisting throughout the investigation. »
«Since articular cartilage is critically dependent on synovial fluid formation for its nutrition, loss of neurovascular control of the synovial microcirculation could contribute to the degenerative changes that commonly accompany chronic inflammatory joint diseases.»
«The role of synovial nerves in the development of various forms of acute inflammation has previously been reported (Lam & Ferel,1991)and it is thought that their efects may be mediated by local release of SP, which is known to be pro-inflammatory in this region.»
«These experiments showed that electrical stimulation of nerves supplying the rat knee joint caused a frequency-dependent constriction of articular bloodvesels, and that topical aplication of SP to the exposed joint surface produced a potent vasodilatation, although this particular effect was found to be transient.»
Viser at nervesignaler gjør at blodkar trekker seg sammen i leddet. Kan henvise til at et overstimulert nervesystem (sympaticus dominans) trekker blodkar sammen.
«A highly significant frequency-dependent decrease in joint bloodflow occurred in normal rats when electrical stimulation of the saphenous nerve was performed (P < 0 001, repeated measures one-way ANOVA; n = 10). The greatest vasoconstriction resulted when 30 Hz stimulation was applied to the nerve: this elicited a 37.3+7.3% fall in perfusion.»
Nevner at Substans P gir vasodilasjon (37%) umiddelbart, men at det over tid gir en vasokonstriksjon (40%).
«Substance P, when applied topically to the exposed surface of normal knee joints, produced a significant dose-dependent augmentation of joint bloodflow (P<0.001;n= 10), culminating in a peak rise of 45*1+8*6% with the10-9 mol dose.»
«At week 1, SP had no significant effect on synovial blood flow (P= 0.511;n= 10),but at week 3 vasoconstriction was recorded (P< 0*001;n= 9); at both these times the results were significantly different from those of normal rats (P < 0.001). A fall of articular perfusion of about 40% occurred at week 3 when 10-8 and10-t2 mol of SP was administered to the joint, but the intermediate doses produced less efect. »
Nevner at blodsirkulasjonen er dårlig i over 3 uker etterpå, selv om betennelsen er borte.
«Since articular cartilage is dependent on the synovial perfusion (McKibbin& Maroudas, 1979), this initial reduction in joint blood flow could cause the integrity of the joint to deteriorate and lead to degenerative changes. It has previously been shown that adjuvant- induced inflammation in the rat knee joint abolishes sympathetic vasoconstriction and the neuropeptidergic vasodilator response to SP at 1week post-treatment (McDougall et al. 1994).The investigation outlined here has shown that these alterations are not transitory, and are stil present 3 weeks after injection of adjuvant, even though the inflammatory process appears to be abating by then.»
Nevner at det blir vasokonstriksjon når det er betennelse samtidig.
«Chronically inflamed joints did not show vasodilatation in response to SP at any stage; indeed there was some evidence of vaso- constriction. This finding suggests that the SP receptors are either radically transformed or possibly inactivated by the inflammatory process.»
«Comparing this finding with that of the present study, it would appear that the integrity of sympathetic transmission and SP receptor activation in rat knee joints declines as inflammation becomes more chronic. Loss of these neurovascular controls could contribute to the degenerative changes that commonly accompany chronic inflammatory joint diseases.»