Tissue disruption

In general, the physical structure of the tissue must be broken down mechanically followed by an extraction procedure, before the sample can be analyzed. Homogenization using blenders, probe homogenizers, cell disrupters, sonicators, or pestle grinders is particularly useful for muscle, liver, and kidney samples. Regardless of the method used for tissue disruption, the pulse, volume of extraction solvent added, and temperature should be validated and standardized in order to ensure reproducible analytical results. During cell disruption, care should be taken to avoid heat build-up in the sample, because the analyte may be heat labile. 

In 1992, Paul and Van Alstyne reported on the processes that occur after tissue disruption in different species of the calcified green seaweed Halimeda [56]. After wounding, these algae transform their major secondary metabolite, the his-enoylacetate diterpene halimedatetraacetate (48), into halimedatrial (50) and epihalimedatrial (51). The structural relationship between the educt and the reaction products suggests that the transformation occurs by a combination of solvolysis and hydrolysis reactions as indicated in Scheme 14 [108]. 

An investigation of the wound reaction of Caulerpa spp. showed that the aldehyde 55 found as minor component in algal extracts is indeed an intermediate in a wound-activated transformation of 54. This sesquiterpene is degraded within seconds after tissue disruption to form the reactive aldehydes 55 and 59-64 that were characterized after trapping reactions (Scheme 17) [121]. 

Upon tissue disruption, the isoxazoline alkaloids 76 and 78 are converted to aeroplysinin-1 (79), which subsequently provides the dienone (80) (Scheme 21). 

In a comparison of RDS, SDS, and RS formation in cooked-cooled potatoes that were intact, coarsely minced, pasted or finely dry-milled the extent of tissue disruption appeared to have little influence on the formation of SDS and RS after cooking (Mishra et al., 2008). The formation of SDS and RS is likely to be more a manifestation of the structure of the starch molecules involved without any constraints imposed by the starch-containing tissue. 

The extractability of I3IJ-labelled plasma albumin from bone pieces and from powdered bone has been compared after both in vivo and in vitro incorporation. Albumin is more readily extracted from bone pieces than from bone powder which implies that tissue disruption exposes additional protein adsorption sites. It has been suggested that incorporation of plasma albumin and other proteins into calcified matrix during bone formation occurs mainly as a result of its strong interaction with bone mineral237 239 240>. 

Unfortunately (or fortunately, depending on one s point of view) the vasculature is not "mushy" like the brain. The collagen and connective tissue content of blood vessels does not allow the gentle homogenization and tissue disruption which has allowed extensive biochemical analysis and binding studies of the brain dopamine receptor(s). Thus, there is a huge void in the biochemical analyses of the peripheral dopamine receptor(s) and mechanisms. There is clearly much to be done in this area for the future. 

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