Other+Hormones

=Insulin= Insulin, a pancreatic hormone, and oral antidiabetic drugs are classified as hypoglycemic drugs because they lower blood glucose levels. Glucagon, another pancreatic hormone, is classified as a hyperglycemic drug because it raises blood glucose levels. Insulin is formed by proteolysis of a large, single chain precursor, proinsulin. In proinsulin the A and B chains are connected by C peptide. Proinsulin is converted to insulin when the C peptide is removed. -regulation of plasma glucose is achieved by the coordination interplay of various nutrients, gastrointestinal hormones, pancreatic hormones, and autonomic NT. Action: insulin affects both glucose utilization and production. Insulin stimulates glucose transport into muscle and fat by promoting translocation of the intracellular transporter, glucose transporter 4, to the cell surface. Insulin inhibits catabolic processes such as breakdown of glycogen, fat, and protein. Pharmacokinetics- half of the insulin secreted by the pancreas is destroyed by the liver. Half-life of exogenous insulin in plasma is 8 min. in the healthy individual. insulin receptor interactions- it is composed of two alpha subunits and two beta subunits linked by disulfide bonds. Binding of the hormone to the alpha subunit of the insulin receptor leads to rapid intramolecular autophosphorylation of tyrosin residues in the B subunits.

Type 1- absolute lack of insulin. Type 2- target cells are relatively insensitive to insulin. This is known as peripheral resistance to insulin. Impaired glucose metabolism in muscle is a key feature of type 2. Insulin therapy- Long-term treatment relies on subQ injections of the hormone. -insulin occurs in the pancreas complexed with the zinc and is extracted in the form of zinc insulin, which is not water soluble at neutral pH. -ultrashort and short-acting insulin: this are soluble. They have a rapid onset. Soluble insulin preparations are the only insulin preparations that maybe given in IV. -intermediate and long acting: the duration of action depends on the size of the particle present. Pharmokenetics-absorption of insulin is affected by the site of injection. Insulin absorption is usually most rapid from the abdominal wall. Adverse effects-hypoglycemia, symptoms include sweating, tremor, blurred vision, weakness, hunger, and confusion. Use this site to develop the concepts surrounding other hormones and their mechanism of action.



__Pituitary Hormones__===


 * **Drug** || **Onset(hrs)** || **Duration(hrs)** || **Trade Names** ||
 * **Rapid-Acting** ||  ||   ||   ||
 * Regular Insulin || 0.5-1 || 5-8 || Humulin R, Novolin R, Regular lletin I, Velosulin. ||
 * Prompt Insulin Zic Suspension || 1-2 || 12-16 || Semilente, Semilente Lletin I, semilente Purified Pork. ||
 * **Intermediate Acting** ||  ||   ||   ||
 * Isophane Insulin Suspension || 1-2 || 24-28 || NPH Insulin, NPH Lletin I and I, NPH ( Puried Pork) Insulin, Humulin N+, Insulatard NPH, Insulatard NPH Human. ||
 * Insulin Zinc Suspension || 1-3 || 24-28 || Humulin L, Lente Insulin, Lente Lletin I an I Novolin L. ||
 * **Long Acting** ||  ||   ||   ||
 * Protamine Zinc Insulin Suspension || 4-8 || >36 || Protamine zic, lletin I and II ||
 * Extended Insuln Zinc Suspension || 4-8 || >36 || Ultralente Insulin, Ultralente Lletin, Ultralente Purified Beef. ||
 * **Combination Products** ||  ||   ||   ||
 * Isophane Insuin Suspension and Insulin Injection || 0.25-1 || 24 || Mixtard Novolin 70/30 ( human) ||

- ↑ glycogenesis - ↑ protein and triglyceride synthesis || - ↑ glycogenesis - ↑ glucose utilization in Kreb cycle - ↑ protein synthesis || - ↑ glycogenesis - ↑ triglyceride synthesis ||
 * **Action of Insulin** ||  ||
 * **Site** || **Action** ||
 * **Muscle** || - ↑ glucose transport into cell
 * **Liver** || - ↑ glucose transport into cell
 * **Adipose** || - ↑ glucose transport into cell

Posterior Pituitary Hormones
===__Vasopressin__ (//Antidiuretic Hormone) Acts on kidneys to increase water reabsortion. Has a long term use for controlling blood pressure and short term use or regulating arterial pressure. V1 receptor responsible for vasoconstrictor action. V2 receptor responsible for antidiurectic effect, lack of this can lead to diabetes insipidus. Pharmacokinetics-Vasopressin can be administered intravenously, Intramuscularly, or intranasally. Half life is 20 minutes and is metabolized in the liver and kidney. Therapeutic uses include treatment of diabetes insipidus, control bleeding in certain conditions, stimulates relaease of von Willebrandfactor and clotting factor VII.//=== ===__Oxytocin__ //Receptors are Gq/11protien linked when stimulated allow increase of Ca++ which causes muscle contraction. Can initiated labor by stimultating uterine contraction and also ejection of milk from lactating mothers. Pharmacokinetics-half life is 5 minutes, is not bound to plasma protien, metabolized in liver and kidney Therapeutic uses- administered intravenously to stimulate labor as well as induce postpartum lactation when breasts are engorged.//===

In women, the major plasma androgen is androstenedione which can be secreted into the bloodstream or converted into testosterone or estradiol by the ovary. Once secreted into the bloodstream, the majority and androgens are transported to their site of action by a hepatic-secreted carrier protein designed as a sex hormone-binding globulin (44% bound) as well as serum albumins and other proteins (54 %bound).
 * Androgens in women**-

__Androgens in men__
 * Most potent androgenic hormones, testosterone, is synthesized by the Leydig cells of the testes, the thecal cells of the ovary, and adrenal cortex. In men testosterone is the principal plasma androgen and is reduced to dihydrotestosterone, the mediator of most actions of the hormone.The irreversible metabolic conversion of trsterone to dihydrotestoserone occurs only in tissues that contain the enzyme 5a-reductase. Testosterone (but not dihydrostestostterone) can also be aromatized to estradiol by a number of extragonadal tissues (primary adipose tissue and skeletal muscle), a common route of estrogen production in men.

__Androgens__ s: may be administered orally, topically, or through intramuscular injections. Testosterone is generally not administered enterally because extensive first pass hepatic metabolism rapidly reduces plasma concentration. Androgens are manifest in every tissue of the body. The more important functions of androgen include (1) male sexual differentiation of wolffian ducts, external genitalia, and brain in utero; (2) development of the adult male phenotype, including growth and maintenance of male sex accessory organs as well as anabolic actions on skeletal muscle, bone, and hair. (3) facilitation of human sexual behavior, and (4) regulation of specific metabolic processes in the liver, kidneys, and salivary glands. __Therapeutic uses__
 * Androgen therapy is for treatment of testosterone in adolescent boys or adult men. Other less common are male senescence, female hypogonadism, enhancement of athletic performance, male contraception.

__Adverse reactions__
 * bladder irritation, breast soreness. In women acne, decrease breast size, hirsutism, enlarged genitalia.

__Drug interaction__
 * effects on anticoagulants, ant diabetic drugs, and insulin. The dentist should use caution when prescribing corticosteroids because concomitant use of androgens and corticosteroids can increase edema and exacerbate existing cardiac hepatic disease.

__Hormones antagonists androgens__
 * block the effect of androgens can be categorized into three groups: inhibitors of testosterone synthesis, androgen receptors antagonists and 5a reductase inhibitors.

Estrogens: The estrogens- Estradiol I the most potent estrogen and is secreated by the ovary, testes, placenta, and peripheral tissues. Estrone is also secreated by the ovarys, however, the principal source in both women and men is through extragonadal conversion of androstenedione in peripheral tissues. In premenopausal women, the most abundant physiologic estrogen is estradiol and in men and postmenopausal women the most abundant estrogen in the plasma is estrone. Like other lipid soluble hormones, estrogen are transported in the blood principally bound to carrier proteins. Estrogens may be administered orally, topically, or through intramuscular injections. Therapeutic uses: The two principal reasons are prevention of conception and to reduce the sequelae associated with declining hormones levels after menopause. Another major use is for postmenopausal women for prevention of osteoporosis-related fractures to vertebral or long bones. Estrogen can prevent symptoms like pruritus vulvae, urinary incontinence, dysuria, dyspareunia associated with a thinning epithelial lining of the vagina or bladder.

Drug interactions : May increase effect of corticosteroids. Barbiturates, phenytoin, Rifampin, carbmazepine, and topiramates all tend to decrease the effects of estrogens because the former drugs induce liver metabolism of estrogens. Estrogen can also increase the therapeutic and toxic effect of corticosteroids.

Hormones antagonists for estrogens: These are agents the modulate activity can be categorized into three groups: selective estrogens receptors modulators (SERM), pure estrogens receptors antagonist, and estrogen synthesis inhibitors. The goal for SERM is to provide agonist activity in tissues where estrogen action is desired and antagonist or no activity in tissues where estrogen activity may be harmful.

Progestins hormones: The principal progestational hormone secreted into bloodstream is progesterone, which is synthesized and secreted by the corpus luteum, placenta, and adrenal cortex. As with androgens, most gesterone is transported in the bloodstream by plasma progesterone metabolites. Metabolic inactivation of progesterone to pregnanediol is accomplished by the liver. These are administered orally, topically or through intramuscular injections. Progesterone is available for enteral administered; however it is generally not administered in this manner because concentration in the bloodstream remain low because of extensive first pass hepatic metabolism.

Therapeutic uses: Similar to estrogens and progestins can be used alone or in combination with estrogens for oral contraception for hormone replacement in postmenopausal women.

Adverse reactions for both estrogens and progestins: Major concerns untoward effects associated with estrogens have involved thromboembolic disorders, neoplasmas, and hypertension. The association between estrogens, progestins, and breast cancer are more controversial. Estrogen therapy has also been implicated in increasing rates of gallbladder disease, nausea, vomiting, breast tenderness, edem, migraine and endometriosis.

Drug interactions: The hepatic enzyme-inducing medication decrease the effect of progestins.

Hormone antagonists for Progestins: Agents block of the effect of progesterone are primarily potent, competitive antagonists of the progesterone receptor. Progesterone receptors antagonists such s mifepristone can be used as contraceptives and abortifacients as well as for the treatment for endometriosis, lieomymoas, breat cancer, and meningiomas. In the US it is primaril used for the termination of early pregnancy.

Implication of dentistry: The homeostasis of the periodontium is a complex, multifactor relationship that involves, at least in part, the endocrine system. Increase in gingival diseases with fluctuating sex steriod hormone levels, even when oral hygiene remainted unchanged. Furthermore gingival inflammation, gingival probing depths are lager, in pregnant women.