Effect of dietary protein on cholesterol homeostasis in diabetic rats

B. J. Kudchodkar, M. J. Choi Lee, S. M. Lee, N. M. DiMarco, Andras G. Lacko

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Normal streptozotocin (STZ)-diabetic rats were studied in order to examine the effects of altering the type of dietary protein on cholesterol homeostasis. Rats were fed a non-purified or a purified diet containing either casein or soybean protein. The results obtained on the specific aspects of lipid metabolism were remarkably similar in control rats fed the non-purified (Purina Lab Chow) diet or the purified diet with the soybean protein. However, most of the findings obtained with the above two groups were different from those obtained with rats fed the purified diet containing casein. In the latter group, plasma cholesterol was elevated following a 15-day feeding period as compared to the other two dietary groups. The excess plasma cholesterol in the casein-fed group was found in two lipoprotein fractions with densities of 1.023-1.045 g/ml and 1.045-1.086 g/ml, respectively. The latter lipoprotein fraction was also enriched with apolipoprotein E. The casein-fed animals also showed a lower fractional rate of plasma cholesterol esterification and an abnormal accumulation of cholesterol in the body despite inhibition of cholesterol synthesis in the liver and in the intestines. Twelve to 15 days after the induction of diabetes, plasma cholesterol increased to a similar extent in the rats on all three diets. However, the distribution of cholesterol among the lipoprotein fractions was markedly different. The percentage of cholesterol in fractions of d < 1.086 g/ml was increased while that carried in the fraction of d 1.086-1.161 g/ml decreased in the rats fed the nonpurified diet and the casein diet. In contrast, there was no change in the distribution of lipoprotein cholesterol between the diabetic and the control rats fed the soybean protein diet. The hepatic synthesis of cholesterol was unaltered in diabetic rats fed the nonpurified diet and the purified diet with soybean protein, but was increased 2.4-fold in diabetic rats fed casein. Intestinal cholesterol synthesis was increased in all three dietary groups. The increase was highest in the rats fed casein and lowest in rats fed soybean protein. The rate of sterol synthesis in the kidneys was not significantly affected by the diet or diabetes. In all three dietary groups diabetes led to an abnormal accumulation of cholesterol in the body. This accumulation was highest in the casein-fed rats and lowest in those fed the soybean protein diet. The cholesterol content of the kidneys was markedly increased by dietary casein. Dietary casein increased the hepatic as well as intestinal synthesis of fatty acids and their incorporation into triglycerides in the control and in diabetic rats as compared to the rats fed the other two diets. These data suggest that diabetic hypercholesterolemia is due to the increased transport of cholesterol, synthesized de novo by the intestine along with that absorbed (endogenous and/or exogenous) by the intestine. Dietary soybean protein may be beneficial in controlling hyperlipidemia but not the hyperglycemia associated with STZ-induced diabetes.

Original languageEnglish
Pages (from-to)1272-1287
Number of pages16
JournalJournal of Lipid Research
Volume29
Issue number10
StatePublished - 1 Jan 1988

Fingerprint

Dietary Proteins
Nutrition
Rats
Homeostasis
Caseins
Cholesterol
Soybean Proteins
Diet
Medical problems
Rat control
Plasmas
Intestines
Streptozocin
Hypercholesterolemia
Lipoproteins
Liver
Kidney
Experimental Diabetes Mellitus
Esterification
Apolipoproteins E

Cite this

Kudchodkar, B. J., Choi Lee, M. J., Lee, S. M., DiMarco, N. M., & Lacko, A. G. (1988). Effect of dietary protein on cholesterol homeostasis in diabetic rats. Journal of Lipid Research, 29(10), 1272-1287.
Kudchodkar, B. J. ; Choi Lee, M. J. ; Lee, S. M. ; DiMarco, N. M. ; Lacko, Andras G. / Effect of dietary protein on cholesterol homeostasis in diabetic rats. In: Journal of Lipid Research. 1988 ; Vol. 29, No. 10. pp. 1272-1287.
@article{9058386af61a471fa0ea1356969a53b1,
title = "Effect of dietary protein on cholesterol homeostasis in diabetic rats",
abstract = "Normal streptozotocin (STZ)-diabetic rats were studied in order to examine the effects of altering the type of dietary protein on cholesterol homeostasis. Rats were fed a non-purified or a purified diet containing either casein or soybean protein. The results obtained on the specific aspects of lipid metabolism were remarkably similar in control rats fed the non-purified (Purina Lab Chow) diet or the purified diet with the soybean protein. However, most of the findings obtained with the above two groups were different from those obtained with rats fed the purified diet containing casein. In the latter group, plasma cholesterol was elevated following a 15-day feeding period as compared to the other two dietary groups. The excess plasma cholesterol in the casein-fed group was found in two lipoprotein fractions with densities of 1.023-1.045 g/ml and 1.045-1.086 g/ml, respectively. The latter lipoprotein fraction was also enriched with apolipoprotein E. The casein-fed animals also showed a lower fractional rate of plasma cholesterol esterification and an abnormal accumulation of cholesterol in the body despite inhibition of cholesterol synthesis in the liver and in the intestines. Twelve to 15 days after the induction of diabetes, plasma cholesterol increased to a similar extent in the rats on all three diets. However, the distribution of cholesterol among the lipoprotein fractions was markedly different. The percentage of cholesterol in fractions of d < 1.086 g/ml was increased while that carried in the fraction of d 1.086-1.161 g/ml decreased in the rats fed the nonpurified diet and the casein diet. In contrast, there was no change in the distribution of lipoprotein cholesterol between the diabetic and the control rats fed the soybean protein diet. The hepatic synthesis of cholesterol was unaltered in diabetic rats fed the nonpurified diet and the purified diet with soybean protein, but was increased 2.4-fold in diabetic rats fed casein. Intestinal cholesterol synthesis was increased in all three dietary groups. The increase was highest in the rats fed casein and lowest in rats fed soybean protein. The rate of sterol synthesis in the kidneys was not significantly affected by the diet or diabetes. In all three dietary groups diabetes led to an abnormal accumulation of cholesterol in the body. This accumulation was highest in the casein-fed rats and lowest in those fed the soybean protein diet. The cholesterol content of the kidneys was markedly increased by dietary casein. Dietary casein increased the hepatic as well as intestinal synthesis of fatty acids and their incorporation into triglycerides in the control and in diabetic rats as compared to the rats fed the other two diets. These data suggest that diabetic hypercholesterolemia is due to the increased transport of cholesterol, synthesized de novo by the intestine along with that absorbed (endogenous and/or exogenous) by the intestine. Dietary soybean protein may be beneficial in controlling hyperlipidemia but not the hyperglycemia associated with STZ-induced diabetes.",
author = "Kudchodkar, {B. J.} and {Choi Lee}, {M. J.} and Lee, {S. M.} and DiMarco, {N. M.} and Lacko, {Andras G.}",
year = "1988",
month = "1",
day = "1",
language = "English",
volume = "29",
pages = "1272--1287",
journal = "Journal of Lipid Research",
issn = "0022-2275",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "10",

}

Kudchodkar, BJ, Choi Lee, MJ, Lee, SM, DiMarco, NM & Lacko, AG 1988, 'Effect of dietary protein on cholesterol homeostasis in diabetic rats', Journal of Lipid Research, vol. 29, no. 10, pp. 1272-1287.

Effect of dietary protein on cholesterol homeostasis in diabetic rats. / Kudchodkar, B. J.; Choi Lee, M. J.; Lee, S. M.; DiMarco, N. M.; Lacko, Andras G.

In: Journal of Lipid Research, Vol. 29, No. 10, 01.01.1988, p. 1272-1287.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Effect of dietary protein on cholesterol homeostasis in diabetic rats

AU - Kudchodkar, B. J.

AU - Choi Lee, M. J.

AU - Lee, S. M.

AU - DiMarco, N. M.

AU - Lacko, Andras G.

PY - 1988/1/1

Y1 - 1988/1/1

N2 - Normal streptozotocin (STZ)-diabetic rats were studied in order to examine the effects of altering the type of dietary protein on cholesterol homeostasis. Rats were fed a non-purified or a purified diet containing either casein or soybean protein. The results obtained on the specific aspects of lipid metabolism were remarkably similar in control rats fed the non-purified (Purina Lab Chow) diet or the purified diet with the soybean protein. However, most of the findings obtained with the above two groups were different from those obtained with rats fed the purified diet containing casein. In the latter group, plasma cholesterol was elevated following a 15-day feeding period as compared to the other two dietary groups. The excess plasma cholesterol in the casein-fed group was found in two lipoprotein fractions with densities of 1.023-1.045 g/ml and 1.045-1.086 g/ml, respectively. The latter lipoprotein fraction was also enriched with apolipoprotein E. The casein-fed animals also showed a lower fractional rate of plasma cholesterol esterification and an abnormal accumulation of cholesterol in the body despite inhibition of cholesterol synthesis in the liver and in the intestines. Twelve to 15 days after the induction of diabetes, plasma cholesterol increased to a similar extent in the rats on all three diets. However, the distribution of cholesterol among the lipoprotein fractions was markedly different. The percentage of cholesterol in fractions of d < 1.086 g/ml was increased while that carried in the fraction of d 1.086-1.161 g/ml decreased in the rats fed the nonpurified diet and the casein diet. In contrast, there was no change in the distribution of lipoprotein cholesterol between the diabetic and the control rats fed the soybean protein diet. The hepatic synthesis of cholesterol was unaltered in diabetic rats fed the nonpurified diet and the purified diet with soybean protein, but was increased 2.4-fold in diabetic rats fed casein. Intestinal cholesterol synthesis was increased in all three dietary groups. The increase was highest in the rats fed casein and lowest in rats fed soybean protein. The rate of sterol synthesis in the kidneys was not significantly affected by the diet or diabetes. In all three dietary groups diabetes led to an abnormal accumulation of cholesterol in the body. This accumulation was highest in the casein-fed rats and lowest in those fed the soybean protein diet. The cholesterol content of the kidneys was markedly increased by dietary casein. Dietary casein increased the hepatic as well as intestinal synthesis of fatty acids and their incorporation into triglycerides in the control and in diabetic rats as compared to the rats fed the other two diets. These data suggest that diabetic hypercholesterolemia is due to the increased transport of cholesterol, synthesized de novo by the intestine along with that absorbed (endogenous and/or exogenous) by the intestine. Dietary soybean protein may be beneficial in controlling hyperlipidemia but not the hyperglycemia associated with STZ-induced diabetes.

AB - Normal streptozotocin (STZ)-diabetic rats were studied in order to examine the effects of altering the type of dietary protein on cholesterol homeostasis. Rats were fed a non-purified or a purified diet containing either casein or soybean protein. The results obtained on the specific aspects of lipid metabolism were remarkably similar in control rats fed the non-purified (Purina Lab Chow) diet or the purified diet with the soybean protein. However, most of the findings obtained with the above two groups were different from those obtained with rats fed the purified diet containing casein. In the latter group, plasma cholesterol was elevated following a 15-day feeding period as compared to the other two dietary groups. The excess plasma cholesterol in the casein-fed group was found in two lipoprotein fractions with densities of 1.023-1.045 g/ml and 1.045-1.086 g/ml, respectively. The latter lipoprotein fraction was also enriched with apolipoprotein E. The casein-fed animals also showed a lower fractional rate of plasma cholesterol esterification and an abnormal accumulation of cholesterol in the body despite inhibition of cholesterol synthesis in the liver and in the intestines. Twelve to 15 days after the induction of diabetes, plasma cholesterol increased to a similar extent in the rats on all three diets. However, the distribution of cholesterol among the lipoprotein fractions was markedly different. The percentage of cholesterol in fractions of d < 1.086 g/ml was increased while that carried in the fraction of d 1.086-1.161 g/ml decreased in the rats fed the nonpurified diet and the casein diet. In contrast, there was no change in the distribution of lipoprotein cholesterol between the diabetic and the control rats fed the soybean protein diet. The hepatic synthesis of cholesterol was unaltered in diabetic rats fed the nonpurified diet and the purified diet with soybean protein, but was increased 2.4-fold in diabetic rats fed casein. Intestinal cholesterol synthesis was increased in all three dietary groups. The increase was highest in the rats fed casein and lowest in rats fed soybean protein. The rate of sterol synthesis in the kidneys was not significantly affected by the diet or diabetes. In all three dietary groups diabetes led to an abnormal accumulation of cholesterol in the body. This accumulation was highest in the casein-fed rats and lowest in those fed the soybean protein diet. The cholesterol content of the kidneys was markedly increased by dietary casein. Dietary casein increased the hepatic as well as intestinal synthesis of fatty acids and their incorporation into triglycerides in the control and in diabetic rats as compared to the rats fed the other two diets. These data suggest that diabetic hypercholesterolemia is due to the increased transport of cholesterol, synthesized de novo by the intestine along with that absorbed (endogenous and/or exogenous) by the intestine. Dietary soybean protein may be beneficial in controlling hyperlipidemia but not the hyperglycemia associated with STZ-induced diabetes.

UR - http://www.scopus.com/inward/record.url?scp=0023787276&partnerID=8YFLogxK

M3 - Article

C2 - 3235914

AN - SCOPUS:0023787276

VL - 29

SP - 1272

EP - 1287

JO - Journal of Lipid Research

JF - Journal of Lipid Research

SN - 0022-2275

IS - 10

ER -

Kudchodkar BJ, Choi Lee MJ, Lee SM, DiMarco NM, Lacko AG. Effect of dietary protein on cholesterol homeostasis in diabetic rats. Journal of Lipid Research. 1988 Jan 1;29(10):1272-1287.