The endocrine system and homeostasis

In the Journal of Biological Physics, Conrad et al (2009) propose using positive and negative feedback loops for restoring homeostasis in the hypothalamus-pituitary-adrenal system.  This system is responsible for controlling stress levels and is stimulated in the second half of the night, when a person is in deep sleep.  If a person cannot reach deep REM sleep, the HPA system cannot restore homeostasis, and that person could suffer depression or obesity.

Just as the HPA system can affect mental health and weight, the pancreas can affect the body’s ability to utilize insulin.   There are a great many studies on the effect of the endocrine system and Diabetes Mellitus.   The pancreatic islets contain alpha cells (A cells) that secrete glucagon and beta cells (B cells) that secrete insulin.   Glucagon controls gycogenolysis; this increases blood sugars.  These elevated blood sugars trigger the pancreas to release insulin to lower the blood sugar levels.  In type 1 diabetes mellitus, the pancreatic islets secrete too little insulin; in type 2 diabetes mellitus, the pancreatic islets secrete insulin but there is an abnormality of insulin receptors (Thibodeau and Patton, 2008). 

In Nutrition Reviews, Wang et al (2012) discuss the protein PANDER and its affect on beta-cell function.  This could lead to repressed glucose-stimulated insulin secretion, leading to Type 2 diabetes.  Finding a way to increase the effect of PANDER on B cell functions could help type 2 diabetics with their insulin production and effectiveness.

In Clinical Endocrinology, Wang et al (2012) also studied the effect of pancreatic secretions on diabetics.  In this study, they studied the glycemic variability of non-diabetic individuals and newly diagnosed type 2 diabetics.  They found more intraday glucose fluctuations in newly diagnosed type 2 patients and patients with impaired glucose regulation than non-diabetic individuals (Wang et al, 2012).

These articles teach us that the endocrine system must work properly for the body to maintain homeostasis and avoid mild to serious diseases.  Current research is still working on finding answers to the best way to utilize the knowledge scientists already have about the functioning of the endocrine system to help combat these diseases.  The first step is to understand how the endocrine system functions with the rest of the body to maintain homeostasis.

References:

Conrad, Matthias; Hubold, Christian; Fischer, Bernd; Peters, Achim. (2009)  Modeling the hypothalamus-pituitary-adrenal system:  homeostasis by interacting positive and negative feedback.  Journal of Biological Physics, (2009) 35: 149-162.  Springer Science & Business Media

Thibodeau, Gary & Patton, Kevin (2008)  Structure & Function of the Body, 13^th Edition.  Mosby Elsevier

Wang, Chun; Lu, Lifang; Yang, Yanzhi; Chen, Dawei; Liu, Guanjian; Chen, Lihong; Song, Yuanxia; He, Liping; Li, Xiujun; Tian, Hasming; Jia, Weiping; Ran, Xingwu (2012).  Glucose fluctuations in subjects with normal glucose tolerance, impaired glucose regulation and newly diagnosed type 2 diabetes mellitus.  Clinical Endocrinology, Vol 76, Issue 6: 810-815.  Wiley-Blackwell.

Wang, Chunjiong; Burkhardt, Brant R; Guan, Youfei; Yang, Jichun (2012)  Role of pancreatic-derived factor in type 2 diabetes:  evidence from pancreatic Beta cells and liver.  Nutrition Reviews Vol. 70(2):  100-106.  Wiley-Blackwell