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Don’t Get Tipsy Over Your Hormones October 21, 2010

Posted by jfalender232 in Behavior, Biology, Health, Physiology.
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Okay here’s the scoop, instead of boring you with the likely event that my fellow classmates might have bestowed upon you with their own blog posts, luckily for you, I pledge to make this the most exciting blog post that you will have the opportunity to read (that means you SHOULD click on the words that are highlighted in blue and underlined–you can thank me later for all the joy these links will give you). So enough with the chit-chat for now, let’s get ready to rumbbleeeee!

College is all about experiencing many new things such as moving away from your annoying parent(s), skipping class because it might be raining outside, meeting a myriad of new people, learning the art of mooching off your friends, and finally being exposed to your new best friend but your worst enemy. No I am not talking about Dean Wormer, hopefully you will never have to meet the dean. I am talking about alcohol, booze, liquor. It could make you the most popular person at night but then keep you strapped down to the bed with the worst hangover imaginable (unless you have to deal with Mike Tyson).  Please allow me to whet your educational appetite with this nugget of information:  “Alcohol dilates the blood vessels, or capillaries, that carry blood just below the surface of the skin. When they expand, the flow of blood to the skin is increased. The skin flushes, causing a warm feeling.” Alright so now that we are all warm and fuzzy inside lets jump in and explore this topic some more.

Alcohol and has many effects on the human body but one of the most important areas of research is the relationship between alcohol and hormones. WedMD defines hormones as “a chemical substance, formed in one organ or part of the body and carried in the blood to another organ or part where they exert functional effects; depending on the specificity of their effects, hormones can alter the functional activity, and sometimes the structure, of just one organ or tissue or various numbers of them.” Furthermore, alcohol has 4 primary areas that can effect: the regulation of blood sugar levels, reproductive functions, calcium metabolism, and bone structure.

Contrary to Def Leppards wish, I don’t want you to pour some sugar on me, so by realizing that your alcohol drinking can affect all three of your glucose sources and the functions of regulatory hormones will go a long way towards having a healthy relationship with your body. “Even in well-nourished people, alcohol can disturb blood sugar levels. Acute alcohol consumption, especially in combination with sugar, augments insulin secretion and causes temporary hypoglycemia. In addition, studies in healthy subjects and insulin-dependent diabetics have shown that acute alcohol consumption can impair the hormonal response to hypoglycemia (*More Info*)”. Maintaining normal blood sugar levels are crucial to the homeostasis of your body.

I would like to take a time-out here and impart some of facts of college life as told by yours truly (WARNING: please take all these facts with a grain of salt): You will spend more time thinking about sex than anything you might learn in a class. That being said, alcohol can have some potentially serious side effects on the reproductive system of both males and females. “In men, reproductive hormones are responsible for sexual maturation, sperm development and thus fertility, and various aspects of male sexual behavior. In women, hormones promote the development of secondary sexual characteristics, such as breast development and distribution of body hair; regulate the menstrual cycle; and are necessary to maintain pregnancy. Chronic heavy drinking can interfere with all these functions. Its most severe consequences in both men and women include inadequate functioning of the testes and ovaries, resulting in hormonal deficiencies, sexual dysfunction, and infertility (*More Info*)”. This is important to keep in mind because for males, extended low levels of testosterone can lead to the developing of feminization of males characteristics such as “breast enlargement”. Women need to be aware of alcohol effects because prolonged drinking can lead to “cessation of menstruation, irregular menstrual cycles, and menstrual cycles without ovulation, early menopause, and increased risk of spontaneous abortions (*More Info*)”. This leads to a creed that all should take to heart: ‘You can always dump your boyfriend or girlfriend, but never ever dump your hormones.’

The final two areas that we are covering in-depth, calcium metabolism and bone structure are closely correlated to one another. Calcium is the main building block of bones and is essential to the cell to cell communication. Speaking of communication relationships, ‘America’s favorite life-guru’ Dr. Phil can answer any communication issues you might have here.

 

I want YOU to meet me at the bar tonight!

The role of alcohol in calcium and bone metabolism can lead to several complications. “Acute alcohol consumption can lead to a transient parathyroid hormone (PTH) deficiency and increased urinary calcium excretion, resulting in loss of calcium from the body (*More Info*). Chronic heavy drinking can disturb vitamin D metabolism, resulting in inadequate absorption of dietary calcium (*More Info*)”.  These decreased calcium levels can potentially lead to bone diseases, most notably, osteoporosis. MedicineNet describes osteoporosis as, “a condition characterized by a decrease in the density of bone, decreasing its strength and resulting in fragile bones. Osteoporosis literally leads to abnormally porous bone that is compressible, like a sponge. This disorder of the skeleton weakens the bone and results in frequent fractures in the bones”. So yes it is possible that if you are not careful, excessive alcohol consumption could lead you to looking like this dashing fellow below.

 

Your other new drinking buddy likes to show off his awesome 'Bitter Beer Face'!!

So the next time you and your friends start to pour shots, shotgun beers, or do keg stands to the greatest 80s song of all time Here I Go Again, just remember that your hormones are relying on you as their designated driver for the night.

Cheers!

Please check out my friend, Wes’ blog, who examines more about alcoholism and its effects on the endocrine. It’s a great read!

The Science of Satiation October 16, 2010

Posted by Kyle in Behavior, Biology, Chemistry, Health, Nutrition, Uncategorized.
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Slow down or you’ll get a stomach ache!

My parents always told me that if I eat my food really fast, I may feel sick later. I am sure most people have experienced this at least once in their life. It seems that the reason for this is…that the faster you eat, the faster your stomach fills up. Your stomach ends up being full, or over-filled, before your body realizes it. By the time you do feel full, it is too late to stop eating and your stomach may feel like it’s going to explode.

It’s bad enough that your favorite meal can cause you pain after you devour it, but that’s not all it will do. Common sense should tell you that eating too much of something can potentially lead to being overweight. So if you’re eating too fast you can end up doing just that, gaining a lot of weight. An article from the British Medical Journal points out that eating too fast triples the risk of being overweight. Makes perfect sense…more food in equals more pounds put on.  But  the next question remains: what are the mechanisms behind all of this?

The science of satiation

An article out of The Endocrine Society’s Journal of Clinical Endocrinology & Metabolism (JCEM) points out that gut hormones my play a part in why people who eat fast end up overeating. As Alexander Kokkinos, MD, PhD, of Laiko General Hospital in Athens, Greece points out, gut hormones that signal the brain to stop eating may be impacted by the rate of eating.  The hormones that Kokkinos article examined were peptide YY (PYY) and glucagon-like peptide (GLP-1) which work to signal to us that we are full after a meal. For the study, the researchers took blood samples from participants after they had all eaten the same meal, however, the amount of time each participant took to eat the meal varied.  Their results showed that the participants who took longer periods of time to eat the meal had higher levels of the gut hormones and felt more full than those who ate their meals faster. So what does this all mean?

Fast food

Your body tries its best to tell you stop eating, but if you don’t get the signal in time it doesn’t matter.  As many Americans go about their day, they consume a massive amount of calories for very little cost. Going through the drive through doesn’t burn nearly as many calories as chasing down a woolly mammoth. Our early ancestors couldn’t go through the drive through for dinner, they had to work for their meal. Not only that, they probably didn’t eat nearly as much as we do today.  Consuming a ton of calories and burning very few  makes someone more likely to be overweight, but if you add in the fact that some people are consuming their meals in only a few minutes and eating large portions, these people are at a much higher risk of gaining weight. So next time you sit down for a meal, try and eat slowly. This will give your gut time to tell your brain that it’s time to quit eating.  Your gut will be happy, and you may just lose a few pounds in the long run.

Decreasing Ageing affect on Memory October 15, 2010

Posted by zach in Health, Medicine, Neuroscience, Physiology.
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Have you recently misplaced your car keys and spent hours trying to find them? A resent article from Science Daily explains how misplacing your keys may be a thing of the past.  A promising new drug candidate is currently being developed at the  University of Edinburgh to reverse age-related memory loss.  The researchers have developed a compound that has improved cognitive function and memory in aging mice. This compound works by blocking an enzyme known as 11beta-HSD1.  As we age our body changes, with these changes comes changes in the concentration of the enzymes in our body.  The cause of these enzymatic changes is not fully known but it can be linked to physiological effects such as stress.

The aging enzyme

11beta-HSD1 is an enzyme that is found in the brain which can produce stress hormones such as the glucocorticoids.  When there are high levels of glucocorticoids in the brain negatively affect memory.  Therefore, if we can find a way to block 11beta-HSD1 we could increase our memory by decreasing the negative pressure on memory. The problem with blocking 11beta-HSD1 is that until now it hasn’t been possible to find a molecule that has a high specificity for blocking only 11beta-HSD1.  After ingesting a synthetic compound that blocks 11beta-HSD1,  mice show a dramatic increase in memory after only ten days.  The increase in memory was quantified by the time it took mice to complete a Y maze.

A burgeoning field of research

The research in the biomedical world is very concentrated on developing medicines that will reduce or even try to eliminate the effects of aging.  In the past I have blogged about how targets of rapamycin act as a master regulator for protein synthesis.  If we could find a drug to regulate that regulated TOR we could in turn regulate aspects of how our body ages.  Maybe some day we will have a set of anti-aging drugs that will allow us to combat all the negative effects that come with growing old.  If researchers can keep developing synthetic compounds to stop memory loss there may be a day when you will never forget where you misplaced your keys.

Using Fish to Detect Estrogen-like Endocrine Disruptors October 15, 2010

Posted by Grace Dible in Biology, Chemistry, Ecology, Environment/Conservation, Genetics, Health, Medicine, Physiology.
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Endocrine disruptors, according to the EPA, are substances which mimic a hormone, stimulate a body to over respond to a stimulus, cause hormones to respond at inappropriate times, or cause an under/over production of a hormone.  The EPA is most concerned with endocrine disrupting chemicals that end up in the environment and affect the environment and wildlife.  Chemicals of more recent concern are synthetic, natural, and mimic estrogens.  These chemicals include 17α-estradiol (found in birth controls) and herbicides like atrazine.  Much of the recent research is trying to determine whether or not these endocrine disruptors are causing intersex fish, which could possibly lead to population declines.

This flow chart shows how endocrine disruptors may lead to sex changes in a fish population.

One way to determine the estrogenic endocrine disruptors in an aquatic environment is to use different transgenic fish as biomarkers, specifically zebrafish (Danio rerio) and medaka (Oryzia latipes).  Current research is underway in order to determine the affects of these different endocrine chemicals on bioactivity.  Both Medaka and Zebrafish can be transgenic with different fluorescent proteins, which were originally found in bioluminescent jelly fish.    At Marian University in Indianapolis, I am currently trying to determine the best methods for determining the affects of estrogen-like endocrine disruptors in transgenic medaka with green fluorescent protein (GFP).  This GFP is expressed in the liver of the fish when a large amount of vitellogenin, an estrogen inducible promoter, is in its system.  Ordinarily, vitellogenin is found in the female medaka liver, but if an endocrine disruptor is in the environment, then a male medaka may be able to express the GFP as well; the GFP is these medaka have a 100% binding affinity to 17α-estradiol.

Medaka fish expressing GFP in the liver

According to recent review on the effects of a supposed endocrine disruptor like atrazine (A Qualitative Meta-Analysis Reveals Consistent Effects of Atrazine on Freshwater Fish and Amphibians – Jason R Rohr and Krista A McCoy – January 2010  Environmental Health Perspectives), they “found little evidence that atrazine consistently caused direct mortality of fish or amphibians, but we found evidence that it can have an indirect and sublethal effects.”  These sublethal effects in fish may include a decrease in motor skills, perceiving predator risk, olfactory sensitivity, and gonadal morphology.  Atrazine may also lead to the body’s production of aromatase, an enzyme that converts testosterone into estrogen.   Studies still need to be done to see if this supposed endocrine disruptor is causing the fish population sex ratios to change or the production of aromatase.

How could this research be beneficial to human health?  Waste water treatment plants currently don’t filter out estrogen-like endocrine disruptors. Right now Dr. Paul Winchester, at the Indiana University School of medicine, is trying to determine whether there is a correlation between the supposed endocrine disruptor atrazine and birth defects.  Another focus of the research is whether or not areas with high amounts of atrazine can lead to higher rates of breast, ovarian, and prostate cancer.   Dr. Paul Winchester recently did an interview with Indianapolis based NUVO magazine to help spread information on this endocrine disruptor so that people are more aware of what is in drinking water.

To see his Dr. Winchester’s full interview click here.  To view the EPA statements on endocrine disruptors click here.

Beta-Blockers: Function and Effects October 15, 2010

Posted by cassie in Health, Medicine, Physiology.
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Catecholamines such as epinephrine and norepinephrine are key players within the endocrine system that are stimulated in response to the “fight or flight” reaction.  When stimulated, these hormones are rapidly released to bring about many physiological changes within the body. Physiologically, epinephrine and norepinephrine bind to adrenergic receptors found in various tissue target sites within the body- specifically in this case, the myocardial tissue of the heart causing a cascade of events. The cascade of events include vasoconstriction of the blood vessels due to increased cardiac output causing strain on the heart and vasculature. However, keep in mind that these effects can vary among target tissues due to the different adrenergic receptors located within each tissue area.

Fig. 1 shows the interaction between the beta-blocker, epinephrine, norepinephrine, and adrenergic receptors. The beta-blockers compete with the catecholamines to block the adrenergic binding sites on the myocardial tissue- thus inhibiting or alleviating muscle contraction, high blood pressure, and increased cardiac output.

Beta blockers…a wonder-drug?

With the increased incidence of abnormal heart rhythms, hypertension, and heart attacks; a catergory of drugs known as beta-blockers have emerged within the pharmaceutical industry to act as preventative and relief measures for these diagnosed health issues. This specific class of drugs work to block the binding sites for epinephrine and norepinephrine on the adrenergic receptors (β1 and β2) found primarily on myocardial tissue- although they have other uses. By blocking the binding sites of these catecholamines, the overall effect is leads to reduced heart rate, along with increased vasodilation of blood vessels resulting in a lowering of blood pressure (see link for more information).

After learning about the stress response on a hormonal level, I became curious regarding efficiency of beta-blockers and how they bring about change in one type of target tissue versus another. Do these drugs have higher affinity for receptors in a specific target tissue? Or is their functionality strictly in terms of concentration? Are there any side-effects one should be aware of that could indicate harmful effects elsewhere in the body after usage?

Varied results.

A recent study in Circulation Research, addresses the specificity of beta-blockers and their varied results. According to the study, beta-blockers should be approached with caution and considered heavily before deciding upon treatment. After analysis of heart therapy combinations, researchers discovered that each beta-blocker has completely different outcomes based on which type of recepor is its target. With the alpha- and beta- receptors as targets, there seems to be an overall benefit to the patient. In contrast, those that target solely the beta- receptors seem to be detrimental in the long run because the heart becomes accustomed to being a more efficient pump but wears out in a shorter amount of time. Other data are congruent with the prior findings, stating that beta-blockers can be selective or non-selective. Non-selective beta-blockers affect all of the systems that epinephrine and norepinephrine interact with normally including the heart, lungs, and blood vessels. Selective on the other hand, involves a very specific target tissue only allowing for a narrow range of effects. Beta-blockers also have side-effects involving the nervous, digestive, and muscular system.

In conclusion, beta-blockers are beneficial and yet sometimes harmful depending on the specificity, severity of the symptoms, and other therapy combinations involved. Beta-blockers have made huge strides for the medical/pharmaceutical field, but ongoing research is necessary to evaluate the entirety of interactions within the body to ensure proper use and full understanding for the future of biomedical research.

Shedding Light on Alcoholism October 15, 2010

Posted by wframe488 in Behavior, Biology.
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Alcohol

Scientists today are investigating the relationships between stress and the over use of alcohol.  Alcoholism has been an ongoing problem since the Egyptians discovered wine 10,000 years ago. According to the Department of Psychopharmacology, at the University of Heidelberg, in Germany, alcohol consumption is an essential part of daily life of many different societies. The benefits that come from the production, sale, and use of these alcoholic beverages have been found to be detrimental to these societies. The World Health Organization ranks alcohol as one of the primary causes of disease and health problems in industrialized countries.

Alcoholism is an addictive behavior that arises from molecular physiology, according to Sillaber, “Alcohol-related diseases, especially alcoholism, are the result of cumulative responses to alcohol exposure, the genetic make-up of an individual, and the environmental perturbations over time”. In 2002 Sillaber and his colleagues published a scientific paper titled “Enhanced and Delayed Stress-Induced Alcohol Drinking in Mice Lacking Functional CRH1 Receptors. With this study they found that there is a relationship between stress and drinking alcohol for the average mouse. They studied corticotropin-releasing hormone (CRH) and how it mediates responses to stress and alcohol intake. What I want to know is why on earth these mice are drinking alcohol? …but anyway, mice that lacked an efficient CRH1 receptor underwent progressive alcohol intake. With repeated stress added to the mice this particular drinking behavior persisted throughout their life. They discovered that this behavior was associated with the up-regulation of N-methyl-D-aspartate receptor (NMDA) subunit (NR2B).  So, alterations of the CRH1 receptor and changes in NR2B subunits could compose a genetic risk factor for alcoholism.  

Hypothalamus-Pituitary-Adrenal (HPA) axis

Cortisol is a steroid hormone or glucocorticoid produced by the adrenal gland. It is released in response to stress, and low levels of blood glucocorticoids. Its primary functions are to increase blood sugar through gluconeogenesis, suppress the immune system, and aid in fat, protein, and carbohydrate metabolism.  The secretion of corticotropin-releasing hormone (CRH) by the hypothalamus triggers pituitary secretion of adrenal corticotrophic hormone (ACTH); ACTH is carried by the blood to the adrenal cortex where it triggers glucocorticoid secretion. It’s a long and confusing process but in the end cortisol should be released. In the study by Sillaber the CRH1 receptors of the mice were ineffective which meant that the pituitary gland was not being stimulated to produce the glucocorticoid, cortisol, to deal with the stressful environment. This then lead to excessive alcohol consumption by the mice. This idea sheds light on a possible influence in humans.

Let’s face it we are all stressed at one point or another and we all have different ways of dealing with this stress. Some go fishing, others listen to music, or exercise, but some of us drink alcohol… and lots of it. According to the results of the Sillaber study it is possible that CRH deficiency could be a factor in human alcoholism. Check out the blog by my friend Joe for additional information.