Characterization and comparative aspects of the serum very low and low density lipoproteins and their apoproteins in the chicken (Gallus domesticus)

Abstract

Sera from young laying chickens, found to be hypertriglyceridemic by serum lipid and lipoprotein analyses, were fractionated by ultracentrifugation into very low ( d < 1.006 g/mL) and low density ( d 1.006-1.063 and 1.024-1.045 g/mL) lipoproteins (VLDL and LDL). The purity of these lipoprotein fractions was evaluated by electrophoretic, immunological, and electron microscopic techniques; their chemical and physical properties were subsequently determined and compared with those of the corresponding human fractions. While an overall resemblance was evident between each chicken fraction and its human counterpart, minor differences were detected in surface charge, chemical composition, and particle size. Both chicken VLDL and LDL exhibited lo\v surface charge upon electrophoresis; the triglyceride content and particle size of the chicken LDL fractions were greater than those of the corresponding human preparations. Immunological studies revealed a partial identity between the VLDL and between the LDL of chicken and man; quantitative microprecipitation showed the cross-reactivity of chicken and human LDL to amount to about 10%. The chicken lipoproteins possessed a common antigenic determinant and reacted strongly to an antiserum to human apolipoprotein B. The presence of an apolipoprotein B like component in chicken VLDL and LDL was confirmed by sodium dodecyl sulfate-

Alterations in plasma lipoproteins and apolipoproteins associated with estrogen‐induced hyperlipidemia in the laying hen

“…Thus the complement of non-apo-B apoproteins in laying hen VLDL appeared less complex than in the immature chicken [13], in accordance with previous studies demonstrating the absence of certain apolipoproteins from chicken VLDL after estrogen treatment [8]. Nonetheless, other investigators [7] have described the occurrence of numerous protein species in laying hen VLDL, which could be attributable to proteolytic products of apo B-100 [39, 401 (see above).…”

“…5). Indeed earlier studies in our laboratory, using analytical ultracentrifugation, suggested that concentrations of Sr 0-12 LDL were below 50 mg/dl in laying hens [7], a finding confirmed upon column chromatographic separation of laying hen LDL [9]. Conversely, some authors have described an increase in LDL levels upon isolation by sequential ultracentrifugation within the density range 1.006 -1.063 g/ml [X, 3611.…”

“…However, the circulating level of these particles (= 200 mg/dl) in the laying hen was some threefold lower than in immature birds (HDL of e 1,052-1 .I30 g/ml, z 600 mg/dl) [13]. Reduction in the levels of lipoproteins of high density in laying hens has previously been observed in analyses involving sequential ultracentrifugation [36], analytical ultracentrifugation [7] and column chromatography [9]. Moreover, this phenomenon is clearly related to the action of estrogens, since it could be reproduced in estrogenized, immature chickens [8].…”

“…All antibodies were used at a dilution of 1 :loo. As we have previously shown that a polyclonal rabbit antiserum to human apo B crossreacts with its chicken counterpart [7], we used such an antiserum in the present studies.…”

Immunological evidence for common antigenic sites in high-density lipoproteins from rainbow trout and man

“…Several immunological studies of the serum low-density lipoprotein (LDL) from both mammalian and non-mammalian species have indicated that the antigenic structure(s) of LDL has been relatively highly conserved during evolution [6,7]; however, only a few comparative immunological studies of serum HDL have been described. Thus dog [8], chicken [9], and marmoset [10] apo Al gave a pattern of partial identity with the human protein.…”