Enzyme Histochemical Studies of Adipose Tissue in Porcine Yellow Fat Disease

Abstract

Abstracr. Adipose tissue of piglets with yellow fat disease had increased activity of nonspecific esterase, 5-nucleotidase, and acid phosphatase. Since these enzymes are associated with different cell structures and damage to these structures can result in increased enzyme activity, they are criteria for pathogenetic study of yellow fat disease.Yellow fat disease is a generalised disorder of fat depots, characterised by extensive adipose-cell degeneration (steatosis) and inflammation of adipose tissue (steatitis). During these processes a progressive peroxidation of unsaturated fatty acids may occur. Lipofuscin pigment, which is responsible for the typical yellow discoloration of the adipose tissue, is the final product of this peroxidation process Several nutritional factors must be considered in the pathogenesis of this disorder. Yellow fat disease can be induced experimentally by feeding rations low in vitamin E and containing relatively large amounts (10-2074) of fish oil. These diets contained a high percentage of polyunsaturated fatty acids. A relatively large intake of these acids is an essential etiological factor, thus increasing their concentration in adipose tissue and other organs. Oxidation of these acids occurs when the tissue concentration of biological antioxidants, for example vitamin E, is not sufficient. Membrane lipids in particular are involved in this peroxidation process, which results in damage to the membranes and cellular degeneration [l, 18, 36, 391.Lipofuscin, a product of polymerisation of peroxides of unsaturated fatty acids with lipoproteins, possibly originates from ceil debris. The early stage of

PANSTEATITIS OF UNKNOWN ETIOLOGY ASSOCIATED WITH LARGE-SCALE NILE CROCODILE (CROCODYLUS NILOTICUS) MORTALITY IN KRUGER NATIONAL PARK, SOUTH AFRICA: PATHOLOGIC FINDINGS

“…Pansteatitis is a nutritional disorder affecting mammals, [4][5][6][7][8][9]13,14,16,22,33,34,41,42,52,57 crocodilians, 12,26,29,36,39,45,51,62 chelonians, 43 fish, 17,23,24,44,51,56 and piscivorus birds 48,53,54,60 that is characterized by inflammation and necrosis of adipose tissue and the resultant deposition of lipofuscin and ceroid pigment in fat stores, kidney, spleen, and liver. Affected fat is nodular to diffusely firm yellowbrown instead of pale glistening yellow or white.…”

“…Affected fat is nodular to diffusely firm yellowbrown instead of pale glistening yellow or white. 5,6,8,16,26,41,55 The pathogenesis is uncertain, but dietary factors are commonly implicated, particularly the balance between dietary polyunsaturated fatty acids and tissue antioxidants concentration. 8 Pansteatitis is commonly associated with ingestion of high levels of dietary unsaturated fatty acids that may have become oxidized through prolonged storage, freezing, or exposure to environmental heat.…”

Fish Oil-induced Yellow Fat Disease in Rats. III. Lipolysis in Affected Adipose Tissue

“…Membrane damage in the affected fat cells probably would prevent the activation of lipase. The increased 5-nucleotidase activity in affected fat cells in rats [5] and pigs [3], however, also may be important. This enzyme plays a part in the catabolism of cyclic AMP ( fig.…”

Fat Embolism Secondary to Yellow Fat Disease in an Appaloosa Horse

“…Ceroid pigment, which is responsible for the typical yellow discoloration of fat, is the final product of this peroxidation process. 6 A 4-year-old female Appaloosa horse with a previous history of colic with diarrhea for 8 days and acute respiratory distress was submitted to the Department of Comparative Pathology, Veterinary Faculty, University of Las Palmas de Gran Canaria, Spain for postmortem examination. No blood tests were performed.…”

“…[6][7][8]11,16 The 2 main causes associated with this disease are 1) high intake of polyunsaturated fatty acids that accumulate in the adipose tissue 16 and 2) vitamin E deficiency, which promotes oxidation of these acids. 6 Clinical signs include anorexia, subcutaneous edema, tachycardia, and episodes of diarrhea, sometimes with fibrin. Most clinical signs are associated with the inflammation of the fat tissue.…”