Glucocorticoids derived from adrenal glands are essential in the long-term prevention of cardiovascular diseases, most importantly ischaemic heart disease. In the present study, I hypothesized that adrenalectomy leads to the development of atherosclerosis in the Low Density Lipoproteins (LDP)-knockout mice. To test this hypothesis, the levels of stress were compared to the development of atherosclerosis in both sham operated and adrenalectomized (ADX) mice. The genetic differences were compared after the sham operation and the adrenalectomy had been conducted. This study demonstrates the effect of ADX on atherosclerosis.
Methods
In this experiment, 12 week old female LDL-receptor knockout mice were used. ADX and SHAM operations were conducted after the mice were exposed to different stressful conditions.
Results
Mice which have undergone adrenalectomy have increased cholesterol and body weight. Atherosclerosis is evident in mice that have undergone adrenalectemoy.
Conclusion
In conclusion, this experiment has found out that adrenalectomy has a significant effect on the development of atherosclerosis.
Introduction
Cardiovascular diseases are a group of disorders which affect the heart and blood vessels, and their causes are diverse. These disorders include coronary heart disease, cardiomyopathy, hypertensive heart disease, inflammatory heart disease, cardiac dysrhythmias, and heart failure. Coronary heart disease, which is also referred to as ischaemic or coronary heart disease, is one of the most common cardiovascular disorder. Ischaemic heart disease is caused by the narrowing or blockage of arteries as a result of atherosclerosis. Atherosclerosis is a condition that arises when cholesterol plaques and/or fatty deposits become deposited in the inner walls of heart arteries. These plaques often interfere with the flow of blood to the heart muscle or the tone and function of the affected heart artery. Due to this blockage, the heart does not receive enough blood supply. Consequently, oxygen and nutrients supply to the heart is altered causing angina or a heart attack. The development of atherosclerosis begins when Low Density Lipoproteins (LDL) enter the endothelial cells in the cell wall where they are oxidized. Oxidized LDL is toxic and induces inflammation. The monocytes, in the blood passing through the artery, respond to the inflammation and engulf the macrophages (cholesterol rich oxidized LDL). These form cells, filled with lipid. The cells die (apoptosis) and leave a lipid core. The body's attempt to heal forms a fibrous cap over the lipid core. LDL growth continues causing the elastic membrane to stretch outward. Arterial remodeling takes place to maintain the artery's shape, however if the lesion continues to grow, the growth will continue inwards when it cannot stretch outward anymore. This narrows the diameter making it less easy for the blood to pass through, and the fibrous cap is now very thin after being stretched, which increases chances of lesion rupture. The body employs several mechanisms to get rid of atherosclerosis. The most common physiological strategy involves the use of glucocorticoids. Glucocorticoids (GCs), which are cholesterol-derived steroids, are stress-response hormones. These hormones are released in response to stress in the body by the adrenal glands. Glucocorticoids reduce the development of atherosclerosis by inhibiting the colony growth of macrophages.
Adrenal glands are responsible for the reduction of stress levels in the body. Stress may be manifested in different forms such as physical stress, chemical stress, thermal stress, emotional and mental stress. Atherosclerosis is a perfect example of a chemical stress. The brain triggers the adrenal glands to release GCs leading to reduced stress levels in the body. The image below is an illustration of the stress reduction pathway. The adrenal gland is divided into the adrenal cortex and adrenal medulla. The adrenal cortex produces epinephrine and norepinephrine (cortisols) and the adrenal medulla produces adrenaline and noradrenalin.
Image 1 the image above shows the pathway by which the
Adrenal glands respond to the signal triggered by the brain.(Complete Wellbeing Solutions, 2010) [1]
Atherosclerosis is a stress inducing disease. The adrenal glands respond to the development of atherosclerosis and release hormones to reduce the development of the disease. When the adrenal glands are removed, there is a sudden decrease in the epinephrine, norepinephrine and other GCs. This alters stress detection-removal pathway. The body is not able to sense the chemical stress induced by atherosclerosis. Reasons for an adrenalectomy could be due to an adrenal mass (incidental adenoma), pheochromocytoma, Conn's Syndrome (aldostrenoma) and Cushing's syndrome (AUA Foundation, 2012). [2]
In the present study, I hypothesized that an adrenalectomy leads to the development of atherosclerosis in the LDL-knockout mice. To test this hypothesis, the levels of stress were compared to the development of atherosclerosis in both sham operated and adrenalectomized (ADX) mice. The genetic differences were compared after the sham operation and the adrenalectomy had been conducted. This study demonstrates the effect of ADX on atherosclerosis.
Methods:
In this experiment 12 week old female LDL-receptor knockout mice were used. Supplied by, my supervisor Menno Hoekstra. The mice were caged in groups of four or five. The drink bottles contained a saline solution, from which the mice could drink at any time, also during fasting. Diet N was made up of cholesterol, fat and cholic acid.
The experiment took place as follows; the mice were 6 weeks old when the ADX and SHAM operations were conducted. At two weeks, the mice gained strength after being fed the chow diet. Blood was drawn at two weeks. At six weeks, the mice were put on diet N and blood was drawn again. At 8 weeks, the mice were sacrificed after blood was drawn.
Sacrificing:
The adrenalectomy takes place when the mice are at an age of 12 weeks after which the mice are kept under strict monitoring for 8 weeks and then sacrificed.
Both, sham and ADX, have their food removed the day before. They will all fast overnight.
The sacrificing will go per cage, so that mistakes can be avoided. Each mouse will be injected with a mix of painkillers, muscle relaxers and sleeping medication. The mice are put back into their cages. Once they have stopped moving we can proceed. Prior to the sacrificing of the mice, they are each weighed. Once the mice are fully sedated and have been weighed, blood is drawn from its eye. The eye ball is removed and the blood is caught in the appropriate containers.
Isolation of peritoneal cells:
A midline incision is made with sterile scissors. The skin is pulled in opposite direction to bear the peritoneal wall. PBS is inserted and the mouse is rolled approx 10 times form left to right. The same syringe is inserted into the mouse and the PBS is drawn collecting peritoneal cells. This is inserted into a 50ml tube.
Next, the peritoneal wall is cut open with sterile scissors. The intestines and bladder are removed to make the liver, kidneys and the heart visible. A needle is injected into the heart with a flow of PSB. The PBS washes out the blood, making it easy to remove the necessary organs for further research. The organs needed for further research are removed and placed in the necessary containers.
Isolation of peritoneal cells was performed in the standard manner.
Weighing of organs:
After sacrificing a selection of the organs were weighed. In this case, the liver, the spleen and the hearts are weighed.
Sysmex:
The sysmex is used to give a detailed blood count. A sample of the blood, drawn during sacrificing, is placed into an eppendorf and is placed into the sysmex apparatus. The apparatus takes up the sample and a blood count is presented. This is repeated for each mouse.
The sysmex is performed in the standard manner.
Cryosectioning and Staining:
Prior to cryosectioning, the organs must be placed in formal fix. This was done during sacrificing.
Next the slides, on which the cryosections will be plated, should be glazed with gelatin. The liver and the heart are sliced and stained. The heart is sliced until all three valves are visible. This was placed onto the slides for staining. The liver is sliced and placed upon slides for staining.
The heart and the liver are both stained with a MOMA stain (monocytes and macrophages) and an Oil Red O stain (lipid staining). Finally the heart is also stained with a Trichrome Accustain (muscle tissue, fat and collagen). The staining was done in the standard manner.
Plaque Analysis:
The hearts of the mice were also examined. This was done by cryosectioning the hearts until all three valves are shown. These sections were placed on a glycerol coated slide and were stained. Using the same slide number for each mouse in each group they were stained with an Oil Red O stain and a MOMA stain. The plaque analysis was done with a computer program and a microscope. (Microscope type: Leica DFC290/DM1000)
Cholesterol:
From the blood serum the cholesterol levels can be measured. The SMART apparatus is used. The plasma is injected into the SMART apparatus and is then divided into 24 fractions. Each fraction is then plated and the plate reader determines the level of the triglycerides. For the triglyceride determination, samples of 2.5 and 5 microlitres were plated and the averages of both results were used in the final plot.
The sample size was altered to 10 microlitres and an additional 2.5 microlitre of cholesterol esterase was added. Other than the previously mentioned alterations, the SMART was performed in the standard manner
Glucocorticoids:
To measure the corticosterone in the blood a RIA kit is used. For each mouse of both groups the corticosterone is measured.
The glucocorticoids were measured in the standard manner with a RIA-kit.
Q-PCR:
From both groups livers were used in the PCR. Five livers from the ADX group and four livers from the SHAM group. The RT-PCR was performed in the standard manner with GAPDH and 36B4 as household genes to determine the expression of ApoA4 and SCD-1.
Household genes
GAPDH: is an enzyme which catalyzes the oxidative phosphorylation of glyceraldehydes 3-phosphate to 1,3-biphosphoglycerate during glycolysis as well as the reverse reaction in tissues involved in gluconegenesis. GAPDH also plays a role in several other processes such as DNA replication, repair and apoptosis. (Zainuddin et al, 2010) [3] From a screening of housekeeping genes, GADPH had the least variability, good levels of expression and stability. (Silver et al, 2006) [4]
36B4: encodes an acidic ribosomal phosphoprotein PO (RPLPO). The protein is part of a pentamic complex that protrudes the cytoplasm to support the GTPhase steps in the translocation of protein synthesis. The gene is proved to be reliable and consistent for use in gene expression analysis. (Akamine et al, 2007) [5] (Laborda, 1991) [6]
Gene expression
ApoA4: is involved with the development of atherosclerosis. A review stated the gene is involved in promoting efficient uptake of triglyceride-rich lipoproteins from the circulation, maintaining normal macrophage lipid homeostasis, playing a role in cellular cholesterol efflux and reverse cholesterol transport, acting as an antioxidant, inhibiting platelet aggregation and modulating immune function. (Davignon et al 1999) [7]
SCD-1: catalyzes the synthesis of monosaturated fatty acids from saturated fatty acids. The gene is located in the endoplasmic reticulum. (Paton et al, 2008) [8] SCD-1 also plays a part in the regulation of inflammatory diseases such as dermatitis, atherosclerosis, and intestinal colitis. (Liu et al, 2011) [9]
Statistics:
Statistical analyses were performed using Graphpad Quickcalcs Software using Grubbs'
test (Graphpad Software, San Diego, CA; http://www.graphphad.com). The significance
of differences was calculated using a Student's t test. P<0.05 was considered significant.
Results
Glucocorticoids
The glucose levels from figure 8 below are seen to reduce highly. It is also evident that the reactivity levels of the sham specimens are higher. However, the two sets of specimens record a drop in the glucocorticoids levels. This may be attributed to the differences in the functioning of the individual bodies and reduction in body activity (Berdanier, 1989). [10]
Figure8. The overall volume of glucocorticoids was higher in the group of mice which fasted a night before.
Cholesterol:
Figure2. Plated cholesterol results from the blood sample taken during the sacrificing of the mice.
Changes in cholesterol levels:
Cholesterol is one of the constituents of blood (Huszar et al, 2000) [11] . During the experiment, the mice were introduced to varying cholesterol levels as can be seen from figure 2. Cholesterol levels vary in the various blood vessels present in the body mass of the mice. Since the mice are subjected to a diet, some cholesterol is absorbed by the body, especially by blood transporting vessels. As the body receives more cholesterol, some of it is deposited on the exterior part of the blood vessels. This is due to the available space that could be used to build up the vessels. When the available space is consumed, the deposits are directed toward the inner side of the vessels. This makes the blood vessels thicker in size. The thickness is attributed to the increased deposition of more material in the walls of the vessels. In figure 2, it is evident that the cholesterol levels gradually rose, but record a drastic fall after some time and is maintained almost constant at some point. This shows the reduction in the excess cholesterol that is not needed in the blood. The blood only requires a given amount of cholesterol in the bloodstream for its functioning.
Weight Change during the Experiment:
There was limited weight gain or loss considering the entire group of mice. Weight loss among the specimens was not considered due to a number of reasons. First, the experiment was not about weight loss or gain thus it was not meant to focus on the average weight of the specimen. Therefore, basing the arguments on the average weight that was gained or lost by the specimen would not be of much significance during the experiment. Secondly, there was no significant weight change experienced by the samples featured in the experiment. Since all the mice had an average weight, there was bound to be a low change in the overall weight. With such low margins with respect to weight loss, there were high chances of recording a high percentage of error, especially when making approximations. Lastly, the average weight was not used as it has no connection with atherosclerosis (Dótsch et al, 2003) [12] .
Monocytes and atherosclerosis:
Considering figure 3, it is evident that the Neutrophils were low in level. This is partially due to the experimental conditions that the specimens are subjected to and focus on the whole period. During the entire experiment, the specimens were isolated from the natural environment which means that they were not exposed to attacks as commonly the case with the natural environment. This was probably the cause for the reduced amount of Neutrophils produced in their bodies for protection. On the other hand, there was high level of monocytes recorded during the experiment. Monocytes are noted to be important in the build-up of body cells and blood vessels. (Shalhoud et al, 1999) [13] When the mice were treated to higher levels of monocytes, their bodies produced a large number of cells. These cells were therefore forced to develop, which resulted in the establishment of thicker blood vessels. It is evident in the end that the level of monocytes was higher due to the increase in activity during their introduction in the specimens' bodies. From the results, it may be noted that when there was increased production of monocytes, the cells had to link up in their reaction to the change and building up of cells. Biologically, they linked up to form thicker cells. This reduced the blood vessel sizes, which could lead to the development of Atherosclerosis. (Davignon et al 1999) [14] This is the end result of thickened walls of blood vessels.
Figure 3.The graph shows the build of white blood cells. The analysis of the white blood cells shows that there is inflammation taking place in the body. Neutrophils, essential for fighting disease, are at an extremely low number of approximately 1ml/L. On average the neutrophils make up 50-70% of WBC. A high level of monocytes can be linked to the build-up of atherosclerosis. As explained in the introduction, the monocytes engulf the macrophages to form foam cells, which die and form a lipid layer, atherosclerosis.
Glucose level, feeding and fasting
As can be seen from figure 5, there was a difference in the glucose level in the blood between the two sets of specimens. The first set of mice was fed with glucose before blood was drawn from them. The glucose levels among elements of the set were high since their bodies enjoyed a constant supply of supplements. When there is constant supply of food and other supplements in the body, the body does not strain to perform daily activities. However, among the specimens that were not fed, it is evident that the glucose level fell. This may be attributed to the use of glucose during in the body processes. (Shalhoub et al 2011) [15] The body gradually balances the level of glucose in the blood using stored glucose if the body goes without food. For instance, the glucose in the mice that were not fed was used to provide energy during the entire period. In the end, there was a reduction in the glucose levels in the body. This could have resulted in higher stress levels in the body. The body had to find other sources of energy to ensure the normal functioning of the body, which resulted in stress.
Figure5. From the graph above we can state that the overall percentage of glucose was higher in the group of mice which were fed. Blood was drawn at two different times, once before fasting and once after fasting.
36B4 Household Gene versus ApoA4 and SCD-1 Gene levels:
The ApoA4 recorded lower means in the experiment due to the prevalent conditions as evidenced by figure 6. During the experiment, the conditions were not conducive for reproduction. However, the SCD-1 results revealed that the presence of protein increased reactivity. This increased the ADX count to twice as high as the previous value. The two specimens' sets displayed different results due to the differences in the concentration of the protein enzymes that they were subjected to. Protein enzymes are known to be highly reactive (Preusch et al 2008) [16] , especially when induced to the body as in the case of SCD-1 in sham. This trend is not observed for the SCD-1 gene levels as it does not undergo the same reaction.
Presence of peritoneal cells
Monocytes are biologically known to bond to cells in the host. Therefore, the presence of merging cells in the body makes it easier for the monocytes to bond. (Paton et al, 2008) [17] As can be seen from figure 4, the macrophages were plentiful. The availability of the macrophages makes it easier for the monocytes to bond. The result is the existence of combined cells. This increases the thickness of the cells as they are embedded with other cells from the macrophages. The results obtained for the AFX and sham mice have a small difference. This could be attributed to the biological resemblance of the two specimens (Silver et al, 2006) [18] . Though there is a small difference in the results, it is evident that the reaction of the monocytes and macrophages is similar.
Sysmex Data peritoneal cells:
Figure 4.Besides the WBC we also looked at the monocytes, the macrophages and the foam cells in the peritoneal cells. The foam cells are the macrophages engulfed by the monocytes.
Mean ApoA4 and SCD-1 Gene levels:
In figure 7, the Sham mice have a higher mean as compared to the ADX mice. This may be credited to the stability of the sham mice in their reaction. However, it is evident that the two sets of specimens experience a steady reduction in the household gene. This may be as a result of the specimens' exposure to experimental controls. In addition, the reduction may be attributed to the dietary constraints (Morand, 2007) [19] .
Figure 7: The graph above displays the mean of the two genes, ApoA4 and SCD-1. The SHAM mice have a higher level of both genes compared to that of the ADX group.
Staining Images:
Liver Cryosections stained with Oil Red O (Fat droplets are stained in red.)
SHAM
ADX
SHAM2
ADX 11
SHAM 7
ADX 17
SHAM 8
ADX 18
SHAM 9
ADX 22
Image 2. The images above are a selection of the Oil red O stained liver cryosections. The blue dots are the nuclei of the cells and the dark red stains for triglycerides and lipids.
Liver Cryosections MOMA stain
SHAM
ADX
SHAM1
ADX 11
1SHAM 2
ADX 12
SHAM 3
ADX 13
SHAM 4
ADX 16
Image 3. The images above are a selection of the MOMA stained liver cryosections. The monocytes and macrophages are stained. The nuclei are stained blue and the surrounding darker red shades are the monocytes and macrophages.
Discussion:
In this experiment the adrenalectomy and the sham surgeries were a source of stress as well as fasting overnight. This is shown by the level of glucocorticoids (GCs) increasing after fasting. Prior to fasting, the levels of GC were already higher than average. This could be due to the developing atherosclerosis. This is an inflammation increasing the level of white blood cells (WBC) which can lead to stress (GCs). The difference in GCs between both groups, prior to and after fasting, is comparable. The increased starting level of GC is affected by the inflammation (atherosclerosis) taking place in the body. The results indicated that the fasted ADX group had more GCs than the fed group. This is due to the initiation of the pathway which lowers the stress level. When stress is induced, hormones target the adrenal glands and the brain to stop the pathway which increases the stress level. However, if there are no adrenal glands present, this pathway cannot take place, thus increasing the level of GC in the blood. (The Franklin Institute Online, 2004) [20] The mice seem 'stressed' all the time due to this increase. There is transrepression, involving binding of glucocorticoid receptors to non-DNA molecules, such as other transcription factors, that lead to changes in gene expression (Morand, 2007). [21] This is a possible reason for the increased levels of glucocorticoids after fasting. Due to the change in stress levels the body reacts and signals the release of glucocorticoids.
Fasting is another source of stress. After fasting, both groups decreased in blood glucose levels. As researched by Martin Haluzik et al., [22] the glucose levels for the ADX group dropped. The adrenalectomy reduces food intake leading to lowered glucose levels. The level of glucose can be linked to the level of glucocorticoids produced. Less glucose is produced due to the low level of glucocorticoids in the adrenalectomized mice. Therefore, insulin secretion inhibition is decreased. (Haluzik et al, 2002) [23] The fasting further reduces the glucose levels as the mice do not take in any food.
The mice were LDL knockout, thus the LDL did not bind to the receptor. We chose to use these types to increase the likely hood of developing atherosclerosis within our experimental period of time. The high level of LDL in the blood may have been a reason for damage to be brought upon the endothelial wall. The ADX and SHAM group both had comparable Very Low Density Lipoproteins (VLDL) levels; however, there was a difference in LDL and HDL levels. The sham group lacked High Density Lipoproteins (HDL). HDL removes fat from the body by binding to it in the bloodstream and carrying it back to the liver for disposal. The HDL is also removed from the blood stream by the adrenal glands. This reasons why the HDL level is low in the ADX group. The ADX group lacked the presence of LDL. The oxidized rich LDL is engulfed by the macrophages and it removed from the bloodstream to create a lipid layer in the arteries and/or heart. The adrenalectomized mice lack the ability to produce the relevant hormones to reduce the level of inflammation in the bloodstream; hence the growth of atherosclerosis is supported. The sham group however, did have their adrenal glands to assist in the buildup of LDL. (Huszar et al, 2000) [24] (Preusch et al, 2008) [25]
From the sysmex data we can say that the level of monocytes is high in both groups. There are several reasons for this occurring; the stress level, fasting and the adrenalectomy. Due to the LDL receptor knockout mice, the level of LDL travelling through the blood was higher; therefore more LDL could enter the endothelial cell walls. A link can be made between the two sysmex data. The blood sysmex had a high level of monocytes; these are released when inflammation is signaled. The peritoneal cells sysmex had high levels of macrophages and a high level of foam cells. This could lead to the concluding of atherosclerosis at an early stage (Shalhoub et al 2011) [26] . Overall the sysmex data can conclude that the effect of an adrenalectomy is the developing of atherosclerosis.
The GADPH gene takes part in apoptosis, which is important in the build-up of atherosclerosis, as mentioned above. The liver and brain are the two biggest sites of synthesis of ApoA4; the adrenal glands are a smaller site of synthesis (Raber et al, 2000) [27] . ApoA4-A gene also promotes the uptake of triglyceride-rich lipoproteins from the circulation (blood). Decrease in the gene leads to a lowered level of atherosclerosis as shown in figure 8 and 9 for the ApoA4A gene. The level of ApoA4 is decreased for the household genes, GADPH and 36B4. The level of ApoA4 is higher for the SHAM group, this is expected due to the relevance of the gene in the development of atherosclerosis. ApoA4 improves atherosclerosis in mice (Davignon et al, 1999). [28] The SCD-1 gene promotes the regulation of atherosclerosis by synthesizing monosaturated fatty acids from saturated fatty acids. The LDL receptor knockout mice have a lowered level of LDL binding. With LDL-receptors on the adrenal glands, the ADX group does not have LDL binding. The SCD-1 gene level is lower, due to a low number of saturated fats being synthesized. However for the SHAM group with household gene 36B4 the level of SCD-1 is almost three times the amount of the ADX. This is possible with the relevant household gene, in this case, 36B4.
The Oil red O stains the triglycerides and lipids, in the cells, red. From the images, we can state that the images taken from the ADX group has more red than that of the SHAM group. This shows us that the level of lipids in the liver has increased after the adrenalectomy. Due to the absence of the adrenal glands, which take part in the lipogenesis and glucogenesis processes in the body, the level of lipids increases. The glucocorticoids are known to play a role in the activating of lipogenic enzymes. With the removal of the adrenal glands the level of glucocorticoids is instantly reduced, leading to an increased volume of lipids in the livers (Bernadier, 1989). [29]
A plaque analysis was performed to create a visual idea of the stage of atherosclerosis in the hearts of the ADX and SHAM mice. By taking the slides which contain the heart with all three valves, each heart was analyzed for the amount of plaque present. The level of plaque increased for the group with ADX mice. The LDL receptor knock out in the mice increased the level of fat as it continued causing the elastic membrane to stretch outward. As it did in the arteries, the blood flow through the heart decreased in volume due to the build-up of the lipid layer.
From the experiment we can link the results, leading to more concluding answers to the question asked. The glucocorticoids were measured before and after fasting, this has shown us that the level increases after fasting, which can be due to the stress suffered. When we link these results to the sysmex blood results, the level of monocytes is very high as well as the level of foam cells in the peritoneal cells sysmex data. In a previous study by P.Libby et al., the link between inflammation and atherosclerosis has been explained. The monocyte chemoattractant protein-1 (MCP-1) appears responsible for the direct migration of monocytes into the intima at sites of lesion formation. In addition to MCP-1, macrophage colony-stimulating factor (M-CSF) contributes to the differentiation of the blood monocyte into the macrophage foam cell (Libby et al, 2002) [30] . This further explains the low level of LDL in the blood sysmex data for the ADX group.
Another link can be made with the foam cell data, the images and the plaque analysis. From the data, we know that the foam cells are present and at a higher level in the ADX group. The images can show us these foam cells, as plaques. From our images we can clearly see a difference in the lipids in each heart. The ADX series of hearts do show a bigger patch of lipids in the endothelial layer (Li et al, 2002). [31]
The genes used for the Q-PCR influenced the developing of atherosclerosis. The SCD-1 gene plays a role in the energy storage, which can be linked to the glucose data. For the data obtained from the glucose levels there, is no significant difference. The glucose levels are comparable for both the ADX and the SHAM group (Dótsch et al, 2003) [32] . The Apo4A genes can inhibit LDL oxidation, decreasing the atherosclerotic lesion. The gene binds to the LDL and acts as a site-specific antioxidant (Wong et al, 2007). [33] This explains the gene expression levels for the sham group being higher; there is more LDL present to which they can bind.
The experiment involved several variables with an aim of establishing the effect of ADX on atherosclerosis. Based on the results of the study, it is certain that without LDL, a rich lipid layer forms in the heart and blood vessels of mice. Without adrenal glands, atherosclerotic systems were observed as no hormone is released to contain inflammation. Mice have been used in experiments that are not suitable for humans as in this case. However, the results obtained in this case are applicable to humans and other mammals considering the similarities in their body functions. We can conclude that an adrenalectomy increase the speed at which one can develop atherosclerosis. Due to the lack of the adrenal glands, there is low input towards the inflammation taking place, which leads to atherosclerotic symptoms. In order to obtain more results, regarding the elements involved in the development of atherosclerosis, further analysis should be done. Due to the time limit this was not possible.
Conclusion
In conclusion, this experiment has found out that adrenalectomy has a significant effect on the development of atherosclerosis. Adrenal-derived GCs reduce the development of atherosclerosis by inhibiting the colony growth of macrophages. However, in the absence of adrenal glands, this activity is reduced, leading to atherosclerosis.
