Comparison of acetate and glucose incorporation into rat and horse skin lipids.

The research evaluates the effectiveness of acetate and glucose in producing lipids within the skin of rats and horses. The study reveals a higher lipid production when using acetate compared to glucose, with the biosynthesis of specific lipid groups in the sebaceous glands of the rat being asynchronous.

Experiment Methodology

• The study involved the use of in vivo pulse labelling of rat and horse skin. It involved injecting [1-14C]acetate and [U-14C]glucose into the skin intradermally—a method referring to the injection of substances into the dermis, an inner layer of skin.
• The researchers then measured the resulting radiolabelled lipids.
• In rats, the lipids were collected via punch biopsies and daily surface lipid collections. Punch biopsies involve the use of a circular blade to obtain a cylindrical tissue sample.
• In comparison, collection from horses was solely through punch biopsies at the injection sites.
• The collected lipids underwent examination by liquid scintillation and a combination of thin-layer chromatography and autoradiography.

Findings

• The recovery of radiolabelled lipids was higher after an injection of the [1-14C]acetate as compared to the [U-14C]glucose in both animal species. This signifies that acetate better facilitates the creation of lipids in rat and horse skin than glucose.
• The surface lipids labelled through acetate in rats contained adequate radiolabels for scientists to track the excretion of 14C in major non-polar lipid classes over time. This data highlights that biosynthesis of these lipid classes in rat’s sebaceous glands is not entirely synchronous—different lipids synthesized at different times.
• In the lipid extracts of horse skin, all the major lipid groups, including phospholipids and glycolipids, were labelled via acetate.
• On the contrary, none of the non-polar lipids and very less of the polar lipids were labelled using glucose. This might suggest glucose as an inefficient substrate for lipid biosynthesis.