Hormones and blood

Nut Cereal

There are many hormones that assist in the production of blood cells and platelets, regulating blood pressure, protection of blood cells and blood clotting.  Where a patient has constant issues with blood pressure or keeping adequate levels of iron, analysis of hormones should be considered.

Erythropoietin (EPO, haematopoietin or haemopoietin)

Erythropoietin is produced mainly in the kidney, by interstitial cells.  Once the hormone is made it protects red blood cells against destruction.  It also stimulates stem cells of the bone marrow to increase the production of red blood cells.

Angiotensin

Angiotensin is a hormone that helps regulate your blood pressure by constricting (narrowing) blood vessels and triggering water and sodium intake.  Angiotensin is part of linked hormones, enzymes, proteins and reactions called the renin-angiotensin-aldosterone system.

There are four different forms of angiotensin: Angiotensin I–IV.  Angiotensin II is the main and active form of the hormone.  If your body has too little or too much angiotensin, it can cause health issues.

Angiotensin II binds to several receptors and affects many different systems and functions, including:

  • Stimulating the release of aldosterone from your adrenal glands, which causes your body to retain sodium and lose potassium through your urine.
  • Increasing blood pressure by narrowing blood vessels.
  • Triggering the sensation of thirst through your hypothalamus.
  • Triggering the desire for sodium through your hypothalamus.
  • Stimulating the release of antidiuretic hormone from your pituitary gland, which causes your kidneys to reabsorb water. (1)

Thrombopoietin

Thrombopoietin is the chemical mediator that regulates the number of platelets in the blood by stimulating an increase in the number and growth of megakaryocytes, thus controlling the rate of platelet production.

Vasopressin

Vasopressin is known as an antidiuretic hormone.  It maintains the appropriate volume of water in the space that surrounds cells within the body.  It plays a role in regulating circadian rhythm, maintains the body’s internal temperature, blood volume and the proper flow of urine from the kidneys.  Nerve cells at the base of the brain (hypothalamus) make and transport vasopressin to the pituitary gland, which then releases the hormone into the bloodstream  If your body produces too much vasopressin, your kidneys may retain water.  If you don’t have enough vasopressin, your kidneys may excrete too much water.  This causes frequent urination and can lead to dehydration, as well as low blood pressure. (2)

Aldosterone

Aldosterone is a steroid hormone produced by the adrenal glands.  It supports the regulation of blood pressure mainly by acting on organs such as the kidney and the colon to increase the amount of sodium reabsorbed into the bloodstream and to increase the amount of potassium excreted in the urine.  Aldosterone also causes water to be reabsorbed along with sodium; this increases blood volume and therefore blood pressure. (3)

Hepcidin

Hepcidin is a peptide hormone produced in the liver that plays a crucial role in iron production and uptake.  Serum iron levels must be tightly regulated to ensure an adequate supply is available for hemoglobin synthesis, without allowing iron overload to occur in the body.  Hepcidin decreases the level of iron by reducing dietary absorption and inhibiting iron release from cellular storage.  Too much hepcidin can lead to problems like iron deficiency, where your body doesn’t absorb enough iron.  Too little hepcidin can cause iron overload, where your body absorbs too much.

Prostaglandins

Most hormones are produced by glands and transported in the bloodstream.  Prostaglandins are produced at the site where they are needed, are produced in nearly all body cells and are part of the body’s way of dealing with injury and illness, where there is inflammation, pain and fever.  When a blood vessel is injured, a prostaglandin called thromboxane stimulates the formation of a blood clot; a muscle in the blood vessel wall contracts to try to prevent blood loss.  Another prostaglandin called prostacyclin has the opposite effect to thromboxane, reducing blood clotting and removing any clots that are no longer needed and causing the muscle in the blood vessel wall to relax.  The opposing effects that thromboxane and prostacyclin have on the blood vessels can control the amount of blood flow and regulate response to injury and inflammation. (4)

References:
  1. Professional, C. C. M. (n.d.-a). Angiotensin. Cleveland Clinic. https://my.clevelandclinic.org/health/articles/23359-angiotensin
  2. Cassata, C. (2023, September 22). What is vasopressin? EverydayHealth.com. https://www.everydayhealth.com/vasopressin/guide/
  3. Aldosterone | You and Your Hormones from the Society for Endocrinology. (n.d.). https://www.yourhormones.info/hormones/aldosterone
  4. Prostaglandins | You and Your Hormones from the Society for Endocrinology. (n.d.). https://www.yourhormones.info/hormones/prostaglandins/

 

 

 

Hormones involved in Digestion

gut health

The gut is a major producer of hormones, with more than 20 known hormones being responsible for controlling food intake, digestion of food, energy expenditure and influence the pleasure of eating.  Some of these digestive hormones target the brain and work in association with the enteric nervous system and is often why the gut is known as the “2nd brain”.

Some of the well known hormones are below:

Gastrin

Gastrin is a hormone that is produced in the lining of the stomach and upper small intestine and is released into the bloodstream.  During a meal, gastrin stimulates the stomach to release hydrochloric acid, which then allows the stomach to break down food and absorb certain vitamins such as vitamin B12.  Gastric acid also acts as a disinfectant.  Gastrin can stimulate the gallbladder to empty its store of bile and the pancreas to secrete enzymes.  Gastrin also stimulates growth of the stomach lining and increases the muscle contractions of the gut to aid digestion. (1)

Ghrelin

Ghrelin is a hormone that is produced and released mainly by the stomach with small amounts also released by the small intestine, pancreas and brain.  It is known as the ‘hunger hormone’ because it stimulates appetite, increases food intake and promotes fat storage.  Ghrelin levels are actually higher in people with lean body weight compared to those who are overweight.  High levels of Ghrelin have also been found in people with certain cancers, anorexia nervosa and cachexia. (2)

Glucagon

Glucagon is made by the pancreas and helps regulate your blood glucose (sugar) levels.  Glucagon increases your blood sugar level and prevents it from dropping too low, whereas insulin, another hormone, decreases blood sugar levels.

Insulin

Insulin is released from the Pancreas and is essential for helping your body use glucose for energy.  If your body cannot produce enough insulin, or your body cannot use the insulin being released, it causes high blood sugar levels.  In most people insulin lowers blood sugar levels, stimulates metabolism of glucose, protein, and fat.  The inability to produce insulin by destruction of beta cells in the pancreas, creates an autoimmune condition which results in Type 1 Diabetes Mellitus and those diagnosed require injections of insulin for the rest of their lives.  Type 2 Diabetes Mellitus is when the body cannot properly use insulin, and is often a result of poor eating and lifestyle habits which results in insulin resistance. (3) (4)

Insulin-like growth factor (IGF-1)

IGF is a hormone that your body makes naturally in the liver and acts much like insulin.  It used to be known as somatomedin.   IGF helps to control growth hormone secretion in the pituitary gland.  IGF works with growth hormones to promote growth and development of bone and tissue.  These hormones also affect how your body metabolizes sugar, or glucose.  IGF and insulin can work together to rapidly reduce the level of glucose in your blood.

Leptin

Leptin is a hormone released by body fat that helps your body maintain normal weight on a long-term basis.  It does this by regulating hunger by providing the sensation of satiety (feeling full).  As leptin is created by stored body fat, the higher level of body fat means a higher release of leptin.  This signal should mean that the person stops eating.  For those on weight loss protocols, as your body fat decreases, your leptin levels decrease, which may signal your body to think that it is suddenly in starvation, which it clearly is not.  This feeling of starvation can stimulate hunger and appetite and can lead to increased food consumption.  (5)

Gastric Inhibitory Peptide (GIP)

GIP is a member of the secretin family of hormones.  It was discovered in extracts of intestine that inhibited gastric motility and secretion of acid, and initially called enterogastrone.  It is secreted from mucosal epithelial cells in the first part of the small intestine.

GIP enhances the release of insulin in response to infusions of glucose.  For this action, it has also been referred to as glucose-dependent insulinotropic peptide.

Secretin

Secretin is a digestive hormone secreted by the wall of the upper part of the small intestine (the duodenum) that regulates gastric acid secretion and pH levels in the duodenum.  When hydrochloric acid passes from the stomach into the duodenum, secretin is released into the bloodstream and stimulates the duct cells of the pancreas to secrete water and bicarbonate.  By this mechanism, hydrochloric acid secreted by the stomach is diluted and neutralized.  Secretin also inhibits the secretion of gastrin, which triggers the initial release of hydrochloric acid into the stomach, and delays gastric emptying. (6)

References

  1. Gastrin | You and Your Hormones from the Society for Endocrinology. (n.d.). https://www.yourhormones.info/hormones/gastrin/
  2. Ghrelin | You and Your Hormones from the Society for Endocrinology. (n.d.). https://www.yourhormones.info/hormones/ghrelin/
  3. (2023, December 6). Type 1 diabetes | Diabetes Australia | Diabetes Australia. Diabetes Australia. https://www.diabetesaustralia.com.au/about-diabetes/type-1-diabetes/
  4. Healthdirect Australia. (2021, November 4). Type 2 diabetes. https://www.healthdirect.gov.au/type-2-diabetes
  5. Professional, C. C. M. (n.d.-d). Leptin & Leptin Resistance. Cleveland Clinic. https://my.clevelandclinic.org/health/articles/22446-leptin
  6. Utiger, R. D. (1998, July 20). Secretin | Definition & Function. Encyclopedia Britannica. https://www.britannica.com/science/secretin