Lipid classes in adipose tissues and liver differ between Shetland ponies and Warmblood horses

Abstract

Fatty acids, as key components of cellular membranes and complex lipids, may play a central role in endocrine signalling and the function of adipose tissue and liver. Thus, the lipid fatty acid composition may play a role in health status in the equine. This study aimed to investigate the fatty acid composition of different tissues and liver lipid classes by comparing Warmblood horses and Shetland ponies under defined conditions. We hypothesized that ponies show different lipid patterns than horses in adipose tissue, liver and plasma. Six Warmblood horses and six Shetland ponies were housed and fed under identical conditions. Tissue and blood sampling were performed following a standardized protocol. A one-step lipid extraction, methylation and trans-esterification method with subsequent gas chromatography was used to analyse the total lipid content and fatty acid profile of retroperitoneal, mesocolon and subcutaneous adipose tissue, liver and plasma. Fatty acids were grouped according to their degree of saturation and their conjugated double bond into the respective lipid classes. In the adipose tissues, saturated fatty acids (SFAs) and n-9 monounsaturated fatty acids (n-9 MUFAs) were most present in ponies and horses. N-6 polyunsaturated fatty acids (n-6 PUFAs), followed by SFAs, were most frequently found in liver tissue and plasma in all animals. Horses, in comparison to ponies, had significantly higher n-6 PUFA levels in all tissues and plasma. In liver tissue, horses had significantly lower hepatic iso-branched-chain fatty acids (iso-BCFAs) than ponies. The hepatic fatty acid composition of selected lipid classes was different between horses and ponies. In the polar PL fraction, horses had low n-9 MUFA and n-3 PUFA contents but higher n-6 PUFA contents than ponies. Furthermore, iso-BCFAs are absent in several hepatic lipid fractions of horses but not ponies. The differences in fatty acid lipid classes between horses and ponies provide key information on the species- and location-specific regulation of FA metabolism, thus affecting health status such as inflammatory responses.

Fatty Acid Content and Composition of the Yakutian Horses and Their Main Food Source: Living in Extreme Winter Conditions

“…According to our data, the efficiency of elongation of 16:0 to 18:0 was significantly higher in the liver while the conversion efficiency of SFAs to MUFAs was higher in the subcutaneous adipose tissue. Similar trends in the conversion efficiency of SFAs to MUFAs and elongation of 16:0 to 18:0 in liver and subcutaneous adipose tissue were reported by Adolph et al for Warmblood horses [25].…”

“…Different contents of C18, C20, and C22 PUFAs in the tissues of the horses may indicate different functions of these PUFAs. Unlike Warmblood horses, the subcutaneous adipose tissue of the Yakutian horses was rich in PUFAs, especially in the omega-3 family [25]. Mordovskaya et al and Slobodchikova et al also noted enrichment of the Yakutian horses' adipose tissue with 18:3n-3 [45,46].…”

“…Desaturase and elongase activity indices were calculated using the product/precursor ratio of the percentages of individual FAs according to the following notation: 16:1n-7/16:0 = ∆9-desaturase, 18:1n-9/18:0 = ∆9-desaturase, 20:4n-6/20:3n-6 and 20:5n-3/20:4n-3 = ∆5-desaturase and 18:0/16:0 = elongase [25]. Additionally, we measured a conversion efficiency of 18:2n-6 to 20:4n-6 (20:4n-6/18:2n-6) and a conversion efficiency of 18:3n-3 to 20:5n-3 (20:5n-3/18:3n-3).…”

The Equine Faecal Microbiota of Healthy Horses and Ponies in The Netherlands: Impact of Host and Environmental Factors

“…Horses and ponies differ in metabolism, and as a result, ponies are more prone to obesity and related disorders such as laminitis and equine metabolic syndrome [45][46][47]. Differences in the prevalence of several gastrointestinal disorders have also been described for horses and ponies [48].…”

The Bovine Hepatic Cell Line BFH12 as a Possible Model for Hepatosteatosis in Dairy Cows

“…To analyze the FA composition with gas chromatography, 1 × 10 7 cells were processed in three sequential steps: extraction of lipids, separation of the lipid classes by thin-layer chromatography, and methylation of the FAs following the protocol from Adolph et al ( 11 ).…”