Effects of dietary cholesterol on hepatic metabolism of triglyceride-rich lipoproteins in the preruminant calf, Bos spp

(1)

HAL Id: hal-00899547

https://hal.archives-ouvertes.fr/hal-00899547

Submitted on 1 Jan 1992

HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Effects of dietary cholesterol on hepatic metabolism of triglyceride-rich lipoproteins in the preruminant calf,

Bos spp

L Leplaix, Dominique Bauchart, Denys Durand, Pm Laplaud, Mj Chapman

To cite this version:

L Leplaix, Dominique Bauchart, Denys Durand, Pm Laplaud, Mj Chapman. Effects of dietary choles-

terol on hepatic metabolism of triglyceride-rich lipoproteins in the preruminant calf, Bos spp. Repro-

duction Nutrition Development, EDP Sciences, 1992, 32 (5-6), pp.490-490. �hal-00899547�

(2)

Effects of dietary cholesterol

on

hepatic

metabolism of triglyceride-rich lipopro-

teins in the preruminant calf, ^Bos spp.

L Leplaix ^{D Bauchart} ^{D Durand} ^PM Laplaud ^MJ Chapman ( 1 INRA, UR Métabolismes Énergétique ^et Lipidique, Theix, 63122 St-Genès Champanelle;

²

Faculté de Médecine et de Pharmacie, La- boratoire de Biochimie Médicale, ⁸⁷⁰²⁵ ^Li-

moges Cedex;

³

^INSERM U321, Hôpital

de la Pitié, Unité de Recherche

sur

les Li-

poprotéines ^et I Athéro-génèse, ⁷⁵⁶⁵¹

Paris Cedex, France)

In preruminant calves fed

a

high ^fat ^milk replac-

er or

in high-production dairy

^cows

during ^the

fat mobilization period, hepatic disorders of fatty acid metabolism may

^occur

and lead to steato- sis. Steatosis could result from

a

limited hepatic

secretion of VLDL-triglyceride (VLDL-TG).

Among ^the lipotrope agents, dietary ^choleste- rol induces

an

increase in VLDL-TG hepatic

^se-

cretion in hamster hepatocytes, ^and

^an

^increase

in plasmatic apoprotein (apoB) VLDL in rabbit and bovine species (Beynen ^et al, 1983). ^Conse- quently, in order to stimulate hepatic production

of VLDL, cholesterol

was

given to 5 male Frie- sian preruminant ^calves (1 ^month old) equipped

with catheters implanted ^{in the} hepatic ^vessels ^to

determine the in vivo net production of TG-rich li-

poproteins by ^{the liver} (Bauchart et al, 1989). ^An-

imals

were

fed

a

conventional milk replacer ^with

or

without cholesterol in which lipids (tallow)

^con-

stituted 22.1 % dry ^matter (DM) ^and proteins

23.7% DM. Cholesterol mixed with milk at

a

1%

DM level

was

given ^for ^{21 d.} ^Blood samples

^were

collected 7 h after the morning ^meal. ^{Plasma li-} poproteins

^were

separated by isopycnic density gradient ultracentrifugation and their respective

chemical composition determined by enzymatic (lipids) ^{and RID} (apoB) ^methods.

Cholesterol treatment induced

a

large ^in-

crease

in plasma ^IDL (31.4

^vs

^4.4 mg/dl) ^and

LDL (114.3

^vs

^41.4 mg/dl) and, ^to

^a

^lesser

^ex-

tent,

^an

increase in VLDL (4.8

^vs

^2.9 mg/dl). ^An

increased proportion of EC at the expense ^of TG

was

observed in VLDL, IDL and LDL. No

apoE

^was

detected in VLDL and IDL particles under both experimental conditions.

A net increase in VLDL secretion by ^{the liver}

was

observed in 2 calves (0.4 ^vs-0.5 mg/min/kg BW) ^but

^no

significant ^effects

^were

^found ^{in 3 oth-}

ers.

In contrast, ^net ^increases ⁱⁿ hepatic uptake

of IDL (-0.4

^vs

^1.4 mg/min/kg BW) ^and ^LDL (-1.0

vs-0.7 mg/mn/kg BW)

^were

noted in all calves.

The results suggest ^that cholesterol may ^not be

a

limiting factor for hepatic ^VLDL-TG

^secre-

tion. However, further investigations

^are

^needed

to characterize the effects of cholesterol

on

TG- rich lipoprotein metabolism in the liver regarding

the nature of dietary fatty acids which

are

Effects of dietary cholesterol on hepatic metabolism of triglyceride-rich lipoproteins in the preruminant calf, Bos spp

HAL Id: hal-00899547

https://hal.archives-ouvertes.fr/hal-00899547

Submitted on 1 Jan 1992

HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Effects of dietary cholesterol on hepatic metabolism of triglyceride-rich lipoproteins in the preruminant calf,

Bos spp

L Leplaix, Dominique Bauchart, Denys Durand, Pm Laplaud, Mj Chapman

To cite this version:

L Leplaix, Dominique Bauchart, Denys Durand, Pm Laplaud, Mj Chapman. Effects of dietary choles-

terol on hepatic metabolism of triglyceride-rich lipoproteins in the preruminant calf, Bos spp. Repro-

duction Nutrition Development, EDP Sciences, 1992, 32 (5-6), pp.490-490. �hal-00899547�

Effects of dietary cholesterol

hepatic

metabolism of triglyceride-rich lipopro-

teins in the preruminant calf, Bos spp.

L Leplaix D Bauchart D Durand PM Laplaud MJ Chapman ( 1 INRA, UR Métabolismes Énergétique et Lipidique, Theix, 63122 St-Genès Champanelle;

Faculté de Médecine et de Pharmacie, La- boratoire de Biochimie Médicale, 87025 Li-

moges Cedex;

INSERM U321, Hôpital

de la Pitié, Unité de Recherche

les Li-

poprotéines et I Athéro-génèse, 75651

Paris Cedex, France)

In preruminant calves fed

high fat milk replac-

in high-production dairy

during the

fat mobilization period, hepatic disorders of fatty acid metabolism may

and lead to steato- sis. Steatosis could result from

limited hepatic

secretion of VLDL-triglyceride (VLDL-TG).

Among the lipotrope agents, dietary choleste- rol induces

increase in VLDL-TG hepatic

cretion in hamster hepatocytes, and

increase

in plasmatic apoprotein (apoB) VLDL in rabbit and bovine species (Beynen et al, 1983). Conse- quently, in order to stimulate hepatic production

of VLDL, cholesterol

given to 5 male Frie- sian preruminant calves (1 month old) equipped

with catheters implanted in the hepatic vessels to

determine the in vivo net production of TG-rich li-

poproteins by the liver (Bauchart et al, 1989). An-

imals

fed

conventional milk replacer with

without cholesterol in which lipids (tallow)

stituted 22.1 % dry matter (DM) and proteins

23.7% DM. Cholesterol mixed with milk at

1%

DM level

given for 21 d. Blood samples

collected 7 h after the morning meal. Plasma li- poproteins

separated by isopycnic density gradient ultracentrifugation and their respective

chemical composition determined by enzymatic (lipids) and RID (apoB) methods.

Cholesterol treatment induced

large in-

in plasma IDL (31.4

4.4 mg/dl) and

LDL (114.3

41.4 mg/dl) and, to

lesser

tent,

increase in VLDL (4.8

2.9 mg/dl). An

increased proportion of EC at the expense of TG

observed in VLDL, IDL and LDL. No

apoE

detected in VLDL and IDL particles under both experimental conditions.

A net increase in VLDL secretion by the liver

observed in 2 calves (0.4 vs-0.5 mg/min/kg BW) but

significant effects

found in 3 oth-

In contrast, net increases in hepatic uptake

of IDL (-0.4

1.4 mg/min/kg BW) and LDL (-1.0

vs-0.7 mg/mn/kg BW)

noted in all calves.

The results suggest that cholesterol may not be

limiting factor for hepatic VLDL-TG

teins in the preruminant calf, ^Bos spp.

L Leplaix ^{D Bauchart} ^{D Durand} ^PM Laplaud ^MJ Chapman ( 1 INRA, UR Métabolismes Énergétique ^et Lipidique, Theix, 63122 St-Genès Champanelle;

Faculté de Médecine et de Pharmacie, La- boratoire de Biochimie Médicale, ⁸⁷⁰²⁵ ^Li-

^INSERM U321, Hôpital

poprotéines ^et I Athéro-génèse, ⁷⁵⁶⁵¹

high ^fat ^milk replac-

during ^the

Among ^the lipotrope agents, dietary ^choleste- rol induces

cretion in hamster hepatocytes, ^and

^increase

in plasmatic apoprotein (apoB) VLDL in rabbit and bovine species (Beynen ^et al, 1983). ^Conse- quently, in order to stimulate hepatic production

given to 5 male Frie- sian preruminant ^calves (1 ^month old) equipped

with catheters implanted ^{in the} hepatic ^vessels ^to

poproteins by ^{the liver} (Bauchart et al, 1989). ^An-

conventional milk replacer ^with

stituted 22.1 % dry ^matter (DM) ^and proteins

given ^for ^{21 d.} ^Blood samples

collected 7 h after the morning ^meal. ^{Plasma li-} poproteins

chemical composition determined by enzymatic (lipids) ^{and RID} (apoB) ^methods.

large ^in-

in plasma ^IDL (31.4

^4.4 mg/dl) ^and

^41.4 mg/dl) and, ^to

^lesser

^2.9 mg/dl). ^An

increased proportion of EC at the expense ^of TG

A net increase in VLDL secretion by ^{the liver}

observed in 2 calves (0.4 ^vs-0.5 mg/min/kg BW) ^but

significant ^effects

^found ^{in 3 oth-}

In contrast, ^net ^increases ⁱⁿ hepatic uptake

^1.4 mg/min/kg BW) ^and ^LDL (-1.0

The results suggest ^that cholesterol may ^not be

limiting factor for hepatic ^VLDL-TG

^needed

known to control hepatic lipid ^and apoprotein synthesis.

Bauchart D, ^Durand D, Laplaud PM, Forgez P, Goulinet S, Chapman MJ (1989) J Lipid ^Res 30,1499-1514

Beynen ^AC, Van Gils LGM (1983) ^Nutr Rep ^Int