The Human Hormonal Systems

Most of us will equate the human hormonal system with the endocrine, blood vessel, hormone system. A closer look will reveal a close interrelationship between 2 vastly different hormone systems; the autocrine (also at times referred to as the paracrine*) and the endocrine. From a health perspective it pays off to know these systems a bit more in detail which is what this article will focus on. Common characteristics of the two systems include that they both depend on hormone receptors; a receptor is “a receptor protein on the surface of a cell […] that binds to a specific hormone”.

*not strictly true – paracrine hormones can communicate between different types of cells whereas autocrine only work on similar types

We will start with the autocrine system since this makes sense in evolutionary perspective; it came first into existence. It is worthwhile to note that several hormones, for an example acetylcholine, are functioning (and synthesized) in both hormonal domains. The description of both systems includes a standardized ending named “Health Perspectives”, while this section is of course written to be relevant to each of the hormonal systems it is reasonable to infer that something that enhances one system will in essence also help balance the other.

Autocrine Hormone System

This system is characterized by its local cellular function. It basically involves one, or multiple, cell(s) releasing locally acting hormones. By “locally acting” I mean that the hormones released will return to act either on the originator cell or its immediate neighbors.  Autocrine hormones do not enter the bloodstream. Since these hormones are the ‘base unit’ of cellular communication they have the power to ‘overrule’ the effects of endocrine hormones – as a metaphor think about them as neighbors or close friends; what they say will most often matter vastly more than any message you may get off the internet (at least short-term).

Example of compound(s) or drug(s) that modifies the activity of the Autocrine system

An excellent, and mass publicized, example of a autocrine activity modifier is aspirin which temporarily disables the two enzymes COX-1 and COX-2 that are essential to the production of a number of the autocrine prostanoid hormones. The good news is that COX-2 repression quells inflammation (and thus helps protect against everything from cancer to arthritis) while COX-1 repression helps stop the production of thromboxanes, which otherwise promote (at times fatal) blood clotting. The bad news is that new study reviews are showing that the increase in bleeding related accidents by supplementing with aspirin makes it so that this practice in essence only makes sense for people who have already suffered from heart-related problems.

Examples of Autocrine hormones

Eicosanoids (“derive[d] from either omega-3 (ω-3) or omega-6 (ω-6) EFAs. The ω-6 eicosanoids are generally pro-inflammatory; ω-3’s are much less so […] with effects on cardiovascular disease, triglycerides, blood pressure, and arthritis“) [source]

Cytokines (“[derived from] proteins, peptides, or glycoproteins. [They are] substances that are secreted by specific cells of the immune system [in the] general region of the pathogen infected cells, so other immune molecules which follow the signal will arrive at that site”) and they hold a (“possible role in […] autoimmune disorders. Several inflammatory cytokines are induced by oxidant stress. The fact that cytokines, themselves trigger the release of other cytokines and lead also to increased oxidant stress, makes them important in chronic inflammatory disorders.”) [source]

Health Perspective

Omega 3 fatty acids are undeniably a very subtle, efficient and proven way of positively helping the autocrine system do its job. Also, should a pro-inflammatory cycle in the autocrine system already be present then a number of compounds, such as Turmeric (Curcumin), are perfectly able to help short-circuit the negative loop by manipulating the expression of inflammatory autocrine factors downwards.

Endocrine Hormone System

Human Endocrine Glands

Human Endocrine Glands

The endocrine system is characterized by its use of the blood system as communication highway for all its hormonal activity. The system has its control unit in the form of the hypothalamus (located in the middle of the brain) which, via the pituitary gland (which is in direct control with the blood stream), links the endocrine system (7 hormonal glands) up with the nervous system. This system lends itself well to illustration so have a look at included image (modified CC licensed image from Wikipedia) for reference.

In essence the hypothalamus gets incoming data in the form of feedback (via both communication via the nervous system and by sampling the amount of hormones in the bloodstream) from another gland that says “enough” or “more” of a given hormone which it uses to regulate production.

Endocrine sets of hormones are often functioning in axis setups; a famous, and often felt, example is the hormonal glucagoninsulin axis. In order for people to be fully functional and awake these two hormones needs to be in balance within a relatively small window. Insulin drives blood glucose down while glucagon drives it up. If we eat moderate amounts of carbohydrate in conjunction with protein then the pancreas uses these two hormones to keep the blood-glucose level within a very tight window. Should we overeat carbohydrate then the blood-glucose will go up a lot, eventually causing a strong release of insulin to drive it back down, this time however, the pancreas will not be able to stop the falling blood-glucose levels because protein is required for glucagon synthesis – result is that we get sleepy after over-eating for example pasta (or drinking fizzy drinks). Since insulin disables use of stored glycogen as energy long term stressing of the pancreas insulin production is likely to cause combination of overweight and eventually diabetes due to falling production of insulin.

Example of compound(s) or drug(s) that modifies the activity of the Endocrine system

Iodine is essential for the production of thyroid hormone. “The thyroid controls how quickly the body burns energy, makes proteins, and controls how sensitive the body should be to other hormones.” Iodine deficiency can lead to “extreme fatigue, goitre, mental slowing, depression, weight gain, and low basal body temperatures.” which happens not just in developing countries but also in Europe: “In Germany it has been estimated to cause a billion dollars in health care costs per year.”) (sources 1 and 2)

Examples of Endocrine hormones

Growth hormone (GH) (Is a “protein-based poly-peptide hormone. It stimulates growth and cell reproduction and regeneration in humans and other animals [.. and is secreted by the] pituitary gland.”) (source)

Pregnenolone (One of several pro-hormones that can undergo further steroid metabolism to be converted into a range of other hormones including the the axis hormones estrogen and progesterone as well as being a “precursor to testosterone and estrone“) (source)

Health Perspective

A re-occurring theme in the above information on the endocrine system has been the hormonal axes and how their maintainance of a fairly tight balance is of vital importance to health – it is worth understanding this process fully to aid this process through diet. After all imbalances can lead to diabetes which is actually being used as a accelerated model of aging. In essence minimizing excess blood glucose through dietary habits, along with exercise to promote healthy GH levels, will likely continue to be the most effective way to stabilize the endocrine system for years to come.

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