Compensatory mechanisms governing the concentration of plasma low density lipoprotein.
To evaluate factors regulating the concentrations of plasma low density lipoproteins (LDL), apolipoprotein B metabolism was studied in nine Pima Indians (25 +/- 2 yr, 191 +/- 20% ideal wt) with low LDL cholesterol (77 +/- 7 mg/dl) and apoB (60 +/- 4 mg/dl) and in eight age- and weight-matched Caucas...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
1986-11-01
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| Series: | Journal of Lipid Research |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S002222752038860X |
| _version_ | 1818650594390310912 |
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| author | B V Howard G Egusa W F Beltz Y A Kesäniemi S M Grundy |
| author_facet | B V Howard G Egusa W F Beltz Y A Kesäniemi S M Grundy |
| author_sort | B V Howard |
| collection | DOAJ |
| description | To evaluate factors regulating the concentrations of plasma low density lipoproteins (LDL), apolipoprotein B metabolism was studied in nine Pima Indians (25 +/- 2 yr, 191 +/- 20% ideal wt) with low LDL cholesterol (77 +/- 7 mg/dl) and apoB (60 +/- 4 mg/dl) and in eight age- and weight-matched Caucasians with similar very low density lipoprotein (VLDL) concentrations, but higher LDL (cholesterol = 104 +/- 18; apoB = 82 +/- 10; P less than 0.05). Subjects received autologous 131I-labeled VLDL and 125I-labeled LDL, and specific activities of VLDL-apoB, intermediate density lipoprotein (IDL)-apoB, and LDL-apoB were analyzed using a multicompartmental model. Synthesis of LDL-apoB was similar (1224 +/- 87 mg/d in Pimas vs 1218 +/- 118 mg/d in Caucasians) but in Pimas the fractional catabolic rate (FCR) for LDL-apoB was higher (0.48 +/- 0.02 vs 0.39 +/- 0.04 d-1, P less than 0.05). In the Pimas, a much higher proportion of VLDL-apoB was catabolized without conversion to LDL (47 +/- 3 vs 30 +/- 5%, P less than 0.01). When all subjects were considered together, LDL-apoB concentrations were negatively correlated with both FCR for LDL-apoB (r = -0.79, P less than 0.0001) and the non-LDL pathway (r = -0.43, P less than 0.05). Also, the direct removal (non-LDL) path was correlated with VLDL-apoB production (r = 0.49, P = 0.03), and the direct removal pathway and FCR for LDL-apoB were correlated (r = 0.49, P = 0.03). In conclusion, plasma LDL appear to be regulated by both the catabolism of LDL and the extent of metabolism of VLDL without conversion to LDL; both of these processes may be mediated by the apoB/E receptor, and appear to increase in response to increasing VLDL production. |
| first_indexed | 2024-12-17T01:52:42Z |
| format | Article |
| id | doaj.art-771bd1661d654c2fbd19bcfbecda113e |
| institution | Directory Open Access Journal |
| issn | 0022-2275 |
| language | English |
| last_indexed | 2024-12-17T01:52:42Z |
| publishDate | 1986-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Lipid Research |
| spelling | doaj.art-771bd1661d654c2fbd19bcfbecda113e2022-12-21T22:08:01ZengElsevierJournal of Lipid Research0022-22751986-11-012711120Compensatory mechanisms governing the concentration of plasma low density lipoprotein.B V HowardG EgusaW F BeltzY A KesäniemiS M GrundyTo evaluate factors regulating the concentrations of plasma low density lipoproteins (LDL), apolipoprotein B metabolism was studied in nine Pima Indians (25 +/- 2 yr, 191 +/- 20% ideal wt) with low LDL cholesterol (77 +/- 7 mg/dl) and apoB (60 +/- 4 mg/dl) and in eight age- and weight-matched Caucasians with similar very low density lipoprotein (VLDL) concentrations, but higher LDL (cholesterol = 104 +/- 18; apoB = 82 +/- 10; P less than 0.05). Subjects received autologous 131I-labeled VLDL and 125I-labeled LDL, and specific activities of VLDL-apoB, intermediate density lipoprotein (IDL)-apoB, and LDL-apoB were analyzed using a multicompartmental model. Synthesis of LDL-apoB was similar (1224 +/- 87 mg/d in Pimas vs 1218 +/- 118 mg/d in Caucasians) but in Pimas the fractional catabolic rate (FCR) for LDL-apoB was higher (0.48 +/- 0.02 vs 0.39 +/- 0.04 d-1, P less than 0.05). In the Pimas, a much higher proportion of VLDL-apoB was catabolized without conversion to LDL (47 +/- 3 vs 30 +/- 5%, P less than 0.01). When all subjects were considered together, LDL-apoB concentrations were negatively correlated with both FCR for LDL-apoB (r = -0.79, P less than 0.0001) and the non-LDL pathway (r = -0.43, P less than 0.05). Also, the direct removal (non-LDL) path was correlated with VLDL-apoB production (r = 0.49, P = 0.03), and the direct removal pathway and FCR for LDL-apoB were correlated (r = 0.49, P = 0.03). In conclusion, plasma LDL appear to be regulated by both the catabolism of LDL and the extent of metabolism of VLDL without conversion to LDL; both of these processes may be mediated by the apoB/E receptor, and appear to increase in response to increasing VLDL production.http://www.sciencedirect.com/science/article/pii/S002222752038860X |
| spellingShingle | B V Howard G Egusa W F Beltz Y A Kesäniemi S M Grundy Compensatory mechanisms governing the concentration of plasma low density lipoprotein. Journal of Lipid Research |
| title | Compensatory mechanisms governing the concentration of plasma low density lipoprotein. |
| title_full | Compensatory mechanisms governing the concentration of plasma low density lipoprotein. |
| title_fullStr | Compensatory mechanisms governing the concentration of plasma low density lipoprotein. |
| title_full_unstemmed | Compensatory mechanisms governing the concentration of plasma low density lipoprotein. |
| title_short | Compensatory mechanisms governing the concentration of plasma low density lipoprotein. |
| title_sort | compensatory mechanisms governing the concentration of plasma low density lipoprotein |
| url | http://www.sciencedirect.com/science/article/pii/S002222752038860X |
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