Abstract

In Part 1 of this series, a range of microscopy techniques used to study the morphology of the fat cell substrate was described, with a view to developing a better understanding of the degreasing process. This paper discusses how these techniques have been used to study the interaction between the ovine adipocyte substrate with lipid hydrolases. Microscopy has revealed that, under alkaline conditions, the triacylglycerol lipase is able to penetrate the fat cell to effect hydrolysis which is calcium dependent. A striking consequence of this reaction is the morphological changes associated with the adipocyte plasma membrane. These structural changes are thought to be due to the contraction of the plasma membrane, caused by the depletion of the intracellular lipid.

The effect of PLA, hydrolysis on the adipocyte substrate is significant, but mechanistically different to that seen with the triacylglycerol lipase. The deformation of the cell is targeted rather than pervasive. which implies that the phospholipids within the plasma membrane are being hydrolysed. causing pitting and localized deformation of the membrane.

These studies demonstrate that gross cellular changes are associated with the hydrolysis of ovine cutaneous adipocyte derived lipid. This is important evidence to suggest that lipid hydrolases can be used to target and hydrolyse ovine storage lipid.