Assignment #17: Lipid
Transport
For good reasons, lipid transport gets a great deal of
attention—this is what involves the HDL and LDL that you’ve probably heard or
read about. These are lipoproteins—lipid + protein = lipoprotein.
A student once told me to remember: HDL = happy and LDL =
lousy to help remember which of the lipoproteins are indicated for better
versus poorer health. However, there are
more lipid transport LIPOPROTEINS than just HDL and LDL. The others are chylomicrons, and VLDL. Each of these (HDL, LDL, VLDL, and
chylomicrons) act differently in the body.
Each gets its name from the density of the compound. The more triglyceride in substance = lower
density. The happy versus lousy
thing? That is determined by what
happens to these lipid-transporting molecules in the body.
Chylomicrons contain the greatest % of triglyceride, whereas
HDL contains the least. In order of
triglyceride content (most to least):
chylomicrons, VLDL, LDL, and HDL.
The blood content of these lipoproteins has major health implications,
and, here begins your assignment.
To help you understand the role of these lipoproteins, and
to help you clarify the 3 types of studies I wanted to you to know (epidemiological,
laboratory-based, human clinical trial), you need to find THREE real studies
that have been performed to examine the effect of these lipoproteins.
You will find and describe to the group studies that
examined any or several of the lipoproteins:
1.
An epidemiological
study: see the screen cast in which I
clarified this for you!
2.
A laboratory-based study: think rats, mice, test-tube, other in-the-lab
type of studies
3.
Human/clinical trial: this should be the ONLY one you describe that
examines treatments/diets/exercise/whatever on individuals. Don’t confuse #1 and #3!
Assignment due 1/24/18 by midnight
1. An epidemiological study: see the screen cast in which I clarified this for you!
ReplyDelete“Distribution of serum lipids and lipoproteins in patients with beta thalassaemia major; an
epidemiological study in young adults from Greece”
Levels of lipids and lipoproteins were assessed in a sample of cardiovascular disease free adults with Beta-thalassaemia major. Of the 192 patients (88 male, 104 female), Lipoprotein-a levels were 8.3 ± 9 mg/dl in men and 8.8 ± 9 mg/dl in women, apolipoprotein-A1 levels were 111 ± 17 mg/dl in men and 123 ± 29 mg/dl in women, and apolipoprotein-B levels were 60 ± 20 mg/dl in men and 59 ± 14 mg/dl in women. Total-to-HDL (High Density Lipoprotein) cholesterol ratios were 3.7 ± 1.2 and 3.8 ± 1.5 in men and women. “The majority of the patients had blood lipid levels (by the exception of HDL-cholesterol) within the normal range, and consequently the prevalence of lipid and lipoprotein abnormalities was much lower as compared to the general population of the same age”.
2. A laboratory-based study: think rats, mice, test-tube, other in-the-lab type of studies
“Lipid-lowering property of Clausena anisum-olens in hypercholesterolemic rats.”
Acute oral toxicity of the extract was determined using female Sprague-Dawley rats. 30 male rats were used and divided into 5 groups and Triton X-100 was administered to induce hypercholesterolemia. After, oral treatment of Atorvastatin and crude ethanol extract was given to rats daily for 14 days. “The total cholesterol, triglycerides, HDL and LDL were determined before induction, after induction, after first week of treatment and after second week of treatment.” Results showed that the crude extract was nontoxic up to 2000mg/kg and the lipid lowering assay showed reduction of serum cholesterol, triglyceridesides, and low density lipoproteins. This showed that the extracts results were comparable to Atorvastatin and would be useful in lowering cholesterol.
3. Human/clinical trial: this should be the ONLY one you describe that examines treatments/diets/exercise/whatever on individuals. Don’t confuse #1 and #3!
“Effect of two lipid-lowering strategies on high-density lipoprotein function and some HDL-related proteins: a randomized clinical trial.”
Compared effects two of lipid-lowering strategies on high density lipoprotein function. 21 patients were analyzed and ransomed to receive atorvastatin or atorvastatin/ ezetimibe combination for 8 weeks. Cholesterol efflux capacity as well as some anti-inflammatory functions based on HDLs. Results showed that post-treatment increase in cholesterol efflux capacities was similar between the groups. “The baseline cholesterol efflux capacity correlated positively with apolipoprotein (apo)A1 and C3, whereas apoA1 and apoC1 showed inverse associations with VCAM-1 expression. The changes in the cholesterol efflux capacity were positively correlated with multiple HDL proteins, especially apoA2”. It was concluded that both increased cholesterol efflux capacity of HDL and multiple HDL proteins showed a correlation with HDL function. “These results indicate that conventional lipid therapy may have additional effects on HDL functions with changes in HDL proteins"