Effects of stimulation on the ultrastructure and Na, K, Cl composition of the fundus of the rat plantar sweat gland

Development and comparison of the methods for quantitative electron probe X‐ray microanalysis analysis of thin specimens and their application to biological material

“…Cryoimmobilization is the method of choice for the majority of biological microanalysis studies (Zierold, ); this is generally followed by cryosectioning and freeze‐drying before analysis. If cryosectioning is not available or the specimen of interest is not amenable to this technique, cryoimmobiliztion can be followed by alternative procedures such as freeze‐drying of the frozen blocks followed by resin embedding (McWilliams et al ., , Wilson et al ., ) or freeze‐substitution followed by low temperature embedding (Blaineau et al ., , Marshall & Wright, ). Although initially the success of these latter procedures was controversial (Roos & Barnard, ; Pålsgård et al ., ), Marshall's group has shown that, provided care is taken, these techniques can provide robust results (Condron & Marshall, ; Marshall & Wright, ).…”

“…However, the units differ depending on the preparation method used being mmoles/kg wet weight specimen for frozen‐hydrated sections, mmoles/kg dry weight specimen for freeze‐dried cryosections and, for resin‐embedded sections, mmoles/kg of specimen plus resin. In the literature, results for resin‐embedded tissues have sometimes been expressed as mmoles/kg dry weight (Roos & Barnard, ; McWilliams et al ., ) even though this does not equate to mmoles /kg of specimen ( Oh dear what a mess! Brij Gupta, Feb 1986 [private communication]); mmoles/kg epoxy‐embedded tissue or mmoles/kg plastic (Roos & Barnard, ; Blaineau et al ., ) are more correct.…”

“…Brij Gupta, Feb 1986 [private communication]); mmoles/kg epoxy‐embedded tissue or mmoles/kg plastic (Roos & Barnard, ; Blaineau et al ., ) are more correct. Sometimes, there is an assumption that resin directly replaces water in the specimen leading to values that approximate to the hydrated state (Wilson et al .,), but concentration values obtained by from the analysis of resin‐embedded tissues generally lie somewhere between specimen wet and dry weight concentrations due to incomplete penetration of the resin and because of shrinkage during freeze‐drying (Hall, ).This problem has been discussed in detail by Hall () who suggested that a ‘tag’ element with a defined characteristic peak could be added to the resin to allow the determination and subtraction of the contribution of the resin to the total continuum reading in a similar way to that in which contributions from extraneous sources such as the grid are dealt with. Correcting the continuum readings in this way would yield results in terms of mmoles/kg dry weight of original specimen.…”