Editing Alpha cell (section)

== Medical significance ==
High levels of glucagon secretion has been implicated in both Type I and [[Type 2 diabetes|Type II diabetes]]. In fact, high levels of plasma glucagon is considered an early sign of the development of both Type I and Type II diabetes.<ref>{{Citation |last1=Smith |first1=Tamar |title=Glucagon Secretion, Regulation of |date=2003-01-01 |url=https://www.sciencedirect.com/science/article/pii/B0123411033001169 |encyclopedia=Encyclopedia of Hormones |pages=74–82 |editor-last=Henry |editor-first=Helen L. |place=New York |publisher=Academic Press |language=en |doi=10.1016/b0-12-341103-3/00116-9 |isbn=978-0-12-341103-7 |access-date=2022-03-22 |last2=Gerich |first2=John E. |editor2-last=Norman |editor2-first=Anthony W.|url-access=subscription }}</ref>

=== Type I Diabetes ===
It is thought that high glucagon levels and lack of insulin production are the main triggers for the metabolic issues associated with [[Type 1 diabetes|Type I diabetes]], in particular maintaining normal blood glucose levels, formation of ketone bodies, and formation of urea.<ref name=":8">{{Cite journal |last1=Bisgaard Bengtsen |first1=Mads |last2=Møller |first2=Niels |date=August 2021 |title=Mini‐review: Glucagon responses in type 1 diabetes – a matter of complexity |journal=Physiological Reports |language=en |volume=9 |issue=16 |pages=e15009 |doi=10.14814/phy2.15009 |issn=2051-817X |pmc=8371343 |pmid=34405569}}</ref> One finding of note is that the glucagon response to hypoglycemia is completely absent in patients with Type I diabetes.<ref name=":8" /> Consistently high glucagon concentrations in the blood can lead to diabetic ketoacidosis,<ref name=":8" /> which is when ketones from lipid breakdown build up in the blood, which can lead to dangerously low blood glucose levels, low potassium levels, and in extreme cases cerebral edema.<ref>{{Cite web |title=Diabetic ketoacidosis - Symptoms and causes |url=https://www.mayoclinic.org/diseases-conditions/diabetic-ketoacidosis/symptoms-causes/syc-20371551 |access-date=2022-03-22 |website=Mayo Clinic |language=en}}</ref> It has been proposed that the reason for the high levels of glucagon found in the plasma of patients with Type I diabetes is the absence of beta cells producing insulin and the reciprocal effect this has on delta cells and the secretion of somatostatin.<ref name=":8" />

=== Type II Diabetes ===
Patients with Type II diabetes will have elevated glucagon levels during a fast and after eating.<ref name=":9">{{Cite journal |last1=Lund |first1=Asger |last2=Bagger |first2=Jonatan I. |last3=Christensen |first3=Mikkel |last4=Knop |first4=Filip K. |last5=Vilsbøll |first5=Tina |date=December 2014 |title=Glucagon and Type 2 Diabetes: the Return of the Alpha Cell |url=http://link.springer.com/10.1007/s11892-014-0555-4 |journal=Current Diabetes Reports |language=en |volume=14 |issue=12 |pages=555 |doi=10.1007/s11892-014-0555-4 |pmid=25344790 |s2cid=6159190 |issn=1534-4827|url-access=subscription }}</ref> These elevated glucagon levels over stimulate the liver to undergo gluconeogenesis, leading to elevated blood glucose levels.<ref name=":9" /> Consistently high blood glucose levels can lead to organ damage, neuropathy, blindness, cardiovascular issues and bone and joint problems.<ref>{{Cite web |title=Hyperglycemia in diabetes - Symptoms and causes |url=https://www.mayoclinic.org/diseases-conditions/hyperglycemia/symptoms-causes/syc-20373631 |access-date=2022-03-22 |website=Mayo Clinic |language=en}}</ref> It is not entirely clear why glucagon levels are so high in patients with Type II diabetes. One theory is that the alpha cells have become resistant to the inhibitory effects of glucose and insulin and do not respond properly to them.<ref name=":9" /> Another theory is that nutrient stimulation of the gastrointestinal tract, thus the secretion of [[gastric inhibitory polypeptide]] and [[Glucagon-like peptide-1]], is a very important factor in the elevated secretion of glucagon.<ref name=":9" />