CARBOHYDRATE METABOLISM – INSULIN DEPENDENT AND INSULIN INDEPENDENT

•Alpha cells producing glucagon (15–20% of total islet cells)•Beta cells producing insulin and amylin (65–80%)•Delta cells producing somatostatin (3–10%)•PP cells (gamma cells) producing pancreatic polypeptide (3–5%)•Epsilon cells producing ghrelin (<1%)

Amylin, or islet amyloid polypeptide (IAPP), is a 37-residue peptide hormone.[1] It is cosecreted with insulin from the pancreatic β-cells in the ratio of approximately 100:1. Amylin plays a role in glycemic regulation by slowing gastric emptying and promoting satiety, thereby preventing post-prandial spikes in blood glucose levels.

The function of PP is to self-regulate pancreatic secretion activities (endocrine and exocrine); it also has effects on hepatic glycogenlevels and gastrointestinal secretions.

•Somatostatin: inhibits alpha cells and beta cells

DISORDERS OF CARBOHYDRATE METABOLISM – INSULIN DEPENDENT AND INSULIN INDEPENDENT

Diabetes Mellitus

 osmotic diuresis.[1] polyuria, dehydration, polydipsia

Complication in Diabetes Mellitus

Action Mechanism of Insulin

Diagnosis of Diabetes Mellitus: Glucose Tolerance Test (GTT)

Galactose Tolerance Test (GTT)

A galactose-tolerance test is presented that is a modification of the method of Colcheret al. 16

Galactose is administered by a single rapid intravenous injection or infusion (350 mg./kg. body weight).

The galactose values during 60–80 min. after the administration are determined in capillary blood and form an approximately straight line in a semilogarithmic system.

The result is expressed as the τ1/2 values for galactose.The galactose determinations are made with a galactose oxidase method.

The test was carried out on a clinical series, and was found to give valuable quantitative information about liver function and to aid in the distinction between parenchymatous and obstructive jaundice.

Galactosemia

Sugar Level in Blood

HYPOGLYCEMIA: Disorders associated with de-regulation of blood glucose

Renal Threshold for Glucose

Regulation of Blood Glucose level

FACTOR INFLUENCING BLOOD GLUCOSE LEVEL

GLYCOGEN STORAGE DISEASE

Pentosuria

Pentosuria is a condition where the sugar xylitol,[1] a pentose, presents in the urine in unusually high concentrations.

It was characterized as an inborn error of carbohydrate metabolism in 1908.[2] It is associated with a deficiency of L-xylulose reductase, necessary for xylitol metabolism.[1][3] 

L-Xylulose is a reducing sugar, so it may give false diagnosis of diabetes, as it is found in high concentrations in urine. However, people with pentosuria do not have nonstandard metabolism of glucose, like diabetics.[4] 

Patients of pentosuria have a low concentration of the sugar d-xyloketose. [5] Using, Phenyl pentosazone crystals, phloroglucin reaction, and absorption spectrum, pentose can be traced back as the reducing substance in urine, with those that have pentosuria. [6]

Research has shown that pentosuria appears in 3 forms.

The most widely studied is essential pentosuria, where a couple of grams of L-xylusol are released into a person’s system daily. [7]

 Xylulose, contained in red blood cells, is composed of both a major and minor isozyme.[8] For those diagnosed with essential pentosuria, the major isozyme appears to be the same as the minor one. [8]

Alimentary pentosuria can be acquired through fruits high in pentose.[7] 

Finally, drug-induced pentosuria can be developed by those exposed to morphine, fevers, allergies, and some hormones. [7]

Those diagnosed with Pentosuria are predominantly of Jewish root. [1] However, it is a harmless defect, and no cure is needed. [9]

Xylulose is a ketopentose, a monosaccharide containing five carbon atoms, and including a ketone functional group. It has the chemical formula C5H10O5. In nature, it occurs in both the L- and D-enantiomers.

PathologyL-Xylulose accumulates in the urine in patients with pentosuria, due to a deficiency in L-xylulose reductase. Since L-xylulose is a reducing sugar like D-glucose, pentosuria patients have been wrongly diagnosed in the past to be diabetic.

Melituria

sugar in the urine; specific types are named for the sugar in question, such as FRUCTOSURIA, GALACTOSURIA, GLYCOSURIA, and LACTOSURIA.

Fructosuria: the presence of fructose in the urine.essential fructosuria a benign, autosomal recessive disorder of carbohydrate metabolism due to a defect infructokinase and manifested only by fructose in the blood and urine.

Excretion of lactose (milk sugar) in the urine; a common finding during pregnancy and lactation, and in newborns,especially premature babies.

lactosuria [lak″to-su´re-ah]elevated levels of lactose, as seen in lactose intolerance or during lactation.

Apolipoprotein

Apolipoproteins are proteins that bind lipids (oil-soluble substances such as fat and cholesterol) to form lipoproteins. They transport the lipids through the lymphatic and circulatory systems.

The lipid components of lipoproteins are insoluble in water. However, because of their detergent-like (amphipathic) properties, apolipoproteins and other amphipathic molecules (such as phospholipids) can surround the lipids, creating the lipoprotein particle that is itself water-soluble, and can thus be carried through water-based circulation (i.e., blood, lymph).

Apolipoproteins also serve as enzyme cofactors, receptor ligands, and lipid transfer carriers that regulate the metabolism of lipoproteins and their uptake in tissues.

ClassesThere are two major types of apolipoproteins. Apolipoproteins B form low-density lipoprotein ("bad cholesterol") particles. These proteins have mostly beta-sheet structure and associate with lipid droplets irreversibly. Most of the other apolipoproteins form high-density lipoprotein ("good cholesterol") particles. These proteins consist of alpha-helices and associate with lipid droplets reversibly. During binding to the lipid particles these proteins change their three-dimensional structure. There are also intermediate-density lipoproteins formed by Apolipoprotein E.There are six classes of apolipoproteins and several sub-classes:•A (apo A-I, apo A-II, apo A-IV, and apo A-V)•B (apo B48 and apo B100)•C (apo C-I, apo C-II, apo C-III, and apo C-IV)•D•E•HExchangeable apolipoproteins (apoA, apoC and apoE) have the same genomic structure and are members of a multi-gene family that probably evolved from a common ancestralgene. ApoA1 and ApoA4 are part of the APOA1/C3/A4/A5 gene cluster on chromosome 11.[3]

Hundreds of genetic polymorphisms of the apolipoproteins have been described, and many of them alter their structure and function.

Lipoprotein lipase (LPL) (EC 3.1.1.34) is a member of the lipase gene family, which includes pancreatic lipase, hepatic lipase, and endothelial lipase. It is a water-soluble enzyme that hydrolyzes triglycerides in lipoproteins, such as those found in chylomicrons and very low-density lipoproteins (VLDL), into two free fatty acids and one monoacylglycerol molecule. It is also involved in promoting the cellular uptake of chylomicron remnants, cholesterol-rich lipoproteins, and free fatty acids.[1][2][3] LPL requires ApoC-II as a cofactor

CHOLESTEROL DISORDERS

TRIGLYCERIDES DISORDERS

KETON BODIES DISORDERS

Gaucher's disease

Gaucher's disease or Gaucher disease (/ɡoʊˈʃeɪ/) (GD) is a geneticdisease in which fatty substances (sphingolipids) accumulate in cells and certain organs. The disorder is characterized by bruising, fatigue, anemia, low blood platelets, and enlargement of the liver and spleen.