Insulin functions

Diabetes mellitus is a chronic condition related to decreased production or impaired use of insulin or a combination of both. The causes of diabetes mellitus are varied, but the consequence of deficient insulin function is an excessive amount of glucose in the blood (i.e., hyperglycemia). There are two types of diabetes mellitus ... 

Regardless of the type of diabetes, two major complications can occur—excess glucose owing to ineffective insulin function and decreased glucose if insulin is provided in excess amounts. The symptoms of diabetes mellitus (hyperglycemia) and a complication of excessive treatment (hypoglycemia) are shown in Table 12-4. 

Hyperglycaemia is less marked than in type I diabetes, because there is some insulin function. Type II diabetics do not become ketoacidotic. Patients are usually overweight and have slower progressing symptoms. They may present with complications of poorly controlled blood glucose, either macrovascular or microvas-cular. Macrovascular complications include ischaemic heart disease, cerebrovascular disease or peripheral vascular disease. Microvascular complications include retinopathy (eyes), nephropathy (kidney) or neuropathy (nerves). Type II diabetes is generally treated through a controlled diet and weight loss. 

The mechanism of action of insulin and its role in protein synthesis is not well understood. It appears that, on a physiologic level, insulin functions as a growth hormone in the human fetus (Villee, 1975) but... 

Metabolic Functions. Chromium (ITT) potentiates the action of insulin and may be considered a cofactor for insulin (137,138). In in vitro tests of epididymal fat tissue of chromium-deficient rats, Cr(III) increases the uptake of glucose only in the presence of insulin (137). The interaction of Cr(III) and insulin also is demonstrated by experimental results indicating an effect of Cr(III) in translocation of sugars into ceUs at the first step of sugar metaboHsm. Chromium is thought to form a complex with insulin and insulin receptors (136). 

Amylin [106602-62-4] (75) (Fig. 4) is a 37-amino acid peptide having approximately 46% sequence similarity to CGRP (33). Amylin is present ia pancreatic P-ceUs along with insulin. It may function as a hormone ia glucoregulation and has been proposed as an etiologic factor ia certain forms of diabetes. Amylin is also present ia dorsal root ganglia (see INSULIN AND OTHER ANTIDIABETIC DRUGS). 

BENZENESULFONIC ACID DERIVATIVES As has been discussed previously, substituted -alkylbenzene-sulfonylureas often possess the property of releasing bound insulin, thus sparing the requirement for insulin injections in adult-onset diabetes. A pyrimidine moiety, interestingly, can serve as a surrogate for the urea function. 

Therapeutic Function Hypoglycemic Chemical Name Isophane insulin Common Name Isophane insulin injection... 

Therapeutic Function Hypoglycemic Chemical Name Insulin zinc suspension Common Name —... 

The natural polymers known as proteins make up about 15% by mass of our bodies. They serve many functions. Fibrous proteins are the main components of hair, muscle, and skin. Other proteins found in body fluids transport oxygen, fats, and other substances needed for metabolism. Still others, such as insulin and vasopressin, are hormones. Enzymes, which catalyze reactions in the body, are chiefly protein. 

Usual dose schedules of streptozotocin involve 500 mg/m2 i.v. during five consecutive days. The major toxicity is renal tubular damage. Treatment of metastatic insulinomas may result in the release of insulin from the tumor and subsequent hypoglycemic coma. Less severe toxicities include diarrhea, anemia, and mild alterations in glucose tolerance or liver function tests. 

Type 2 diabetes is a heterogeneous and progressive endocrine disorder associated with insulin resistance (impaired insulin action) and defective function of the insulin-secreting (3-cells in the pancreatic islets of Langerhans. These endocrine disorders give rise to widespread metabolic disturbances epitomised by hyperglycaemia. The present classes of antidiabetic agents other than insulin act to either increase insulin secretion, improve insulin action, slow the rate of intestinal... 

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