Vasoconstriction Health Dictionary

A substance formed in tissues or blood vessels when there needs to be local or even massive vasoconstriction. The primary precursor is renin, made by the kidneys, and elevated when the blood seems dehydrated or low in volume; the next substance needed for this reaction is a liver protein, angiotensinogen; when both are present in the blood, local factors can then form this pressor substance. Excess production is often implicated in high blood pressure.... angiotensin

Linn.

Family: Palmae; Arecaceae.

Habitat: Native to Malaysia; now grown along the coasts of Karnataka, Kerala, Tamil Nadu, West Bengal, Assam and Maharashtra.

English: Arecanut, Betel Nut.

Ayurvedic: Puuga, Puugi, Kramuka, Ghontaa, Guwaak, Ghorant.

Unani: Fufal, Chhaalia, Supaari.

Siddha/Tamil: Kottai Paakku, Kamugu.

Action: Taeniacide (confined to veterinary medicine), astringent, stimulant.

Along with other therapeutic application, The Ayurvedic Pharmacopoeia of India indicates the use of dried ripe seed in leucorrhoea and vaginal laxity.

Arecanut contains several alkaloids belonging to pyridine group, the most important being arecoline (0.1-0.5%). Arecaidine, guvacine and isoguvacine are also present. Arecoline is an- thelmintic (in animals, not in humans). Arecaidine has no parasympa- thomimetic effects, but only stimulating properties; sedative in higher doses. Isoguvacine produces hypotension.

Contraindicated in asthma due to bronchoconstrictive effects of the alkaloid arecoline (human case reports). (Francis Brinker.)

Arecanut tannins (8.0-18.0%) are predominantly catechol tannins which closely resemble Mimosa bark tannins. Powdered nuts are prescribed in diarrhoea and urinary disorders. In combination with other astringent and styptic herbs, arecanut is used as a major constituent in confections of Indian medicine for gynaecological disorders.

Aqueous extract of the nut exhibits direct vasoconstriction and adrenaline potentiation in rats. Antimicrobial activity is due to polyphenolic fraction. Tannins potentiated the action of acetylcholine in ileum and uterus of rat and noradrenaline on seminal vesicle at low concentration.

Due to increased incidence of oral cancer associated with betel chewing, the use of arecanut as a masticatory is being discouraged.

Seeds are toxic at 8-10 g, fluid extract at 3.7 ml; and arecoline hydrobromide at 4.3-6.5 mg. (Francis Brinker.)

Dosage: Dried ripe fruit—1-2 g powder. (API Vol. I.)... areca catechu

Linn.

Family: Rutaceae.

Habitat: Cultivated in Khasi hills and Cachar. Also in Guntur (Andhra Pradesh). Found in semiwild state in the Naga and Khasi hills.

English: Citrus dulcis, Sour Orange, Sweet Orange.

Folk: Khattaa.

Siddha/Tamil: Mallikanarangi.

Action: Peel—laxative, feeble stomachic, emmenagogue. Leaves— prescribed in the treatment of arthritis and bronchitis. Flowers— aqueous extract is employed in scurvy, fever, inflammation, nervous and hysterical cases. Fruit— a decoction is used to recover from cachexia left by intermittent fever and in cases of enlarged spleen. Dried rind—used in atonic dyspepsia.

Key application: Cut peel—in loss of appetite and dyspeptic ailments. (German Commission E.). As a bitter tonic. (British Pharmacopoeia.)

The main constituents of the peel include the alkaloid synephrine and N- methyltyramine. Synephrine, an alpha 1-adrenergic agonist, stimulates a rise in blood pressure through vasoconstriction. N-methyltyramine also raises blood pressure.

The root gave xanthyletin. The essential oil exhibits antifun- gal activity, it was found effective in treatment-resistant fungal skin diseases. (Expanded Commission E Monographs.)

Commercially available Citrus vul- garis (bitter orange) extracts are often promoted for weight loss due to purported thermogenic effects. In animal models, synephrine causes weight loss, but also increases cardiovascular toxic- ity. (Natural Medicines Comprehensive Database, 2007.)... citrus aurantium

Drugs which relieve nasal congestion and stu?ness. They may be given orally or by nasal spray, and most are SYMPATHOMIMETIC DRUGS which cause vasoconstriction in the nasal mucosa. Too frequent use reduces their e?ectiveness, and there is a danger of ‘rebound’ worsening if they are used for more than 10–14 days. A safer option for babies is simple sodium chloride drops. Warm moist air is also a traditional e?ective decongestant.... decongestants

The term applied to a condition which develops as a result of prolonged immersion of the feet in cold or cool water. It was a condition commonly seen during World War II in shipwrecked sailors and airmen who had crashed into the sea, spending long periods there before being rescued. Such prolonged exposure results in VASOCONSTRICTION of the smaller arteries in the feet, leading to coldness and blueness and ?nally, in severe cases, to ulceration and GANGRENE. (See also TRENCH FOOT.)... immersion foot

Sm.

Family: Liliaceae.

Habitat: Temperate Himalayas from Simla to Bhutan and in Lushai and Aka Hills. Haimavati, Shveta-

Action: Plant—sedative, analgesic, haemostatic, anthelmintic.

The rhizome contains a glucoside, alpha-paristyphnin, which exhibited a depressant action on carotid pressure, myocardium, and respiratory movements experimentally. It produced vasoconstriction in kidney, but vasodilation in the spleen and limbs, and stimulated isolated intestines.... paris polyphylla

deterioration in renal function (of more than 25%) after administration of radiocontrast material. Development of this condition is more likely when there is pre-existing renal disease (the most important factor) or diabetes, vasoconstriction, simultaneous use of NSAIDs, and large amounts of radiocontrast are used. It is thought that the radiocontrast induces vasoconstriction in the vessels supplying the medulla of the kidney and aggravates hypoxia in this part of the kidney.... contrast nephropathy

This results from the action of extreme cold (below 0 °C) on the skin. VASOCONSTRICTION results in a reduced blood – and hence, oxygen

– supply, leading to NECROSIS of the skin and, in severe cases, of the underlying tissues. Chie?y affecting exposed parts of the body, such as the face and the limbs, frostbite occurs especially in people exercising at high altitudes, or in those at risk of peripheral vascular disease, such as diabetics (see DIABETES MELLITUS), who should take particular care of their ?ngers and toes when in cold environments.

In mild cases – the condition sometimes known as frostnip – the skin on exposed parts of the body, such as the cheeks or nose, becomes white and numb with a sudden and complete cessation of cold and discomfort. In more severe cases, blisters develop on the frozen part, and the skin then gradually hardens and turns black until the frozen part, such as a ?nger, is covered with a black shell of dead tissue. Swelling of the underlying tissue occurs and this is accompanied by throbbing and aching. If, as is often the case, only the skin and the tissues immediately under it are frozen, then in a matter of months the dead tissue peels o?. In the most severe cases of all, muscles, bone and tendon are also frozen, and the affected part becomes cold, swollen, mottled and blue or grey. There may be no blistering in these severe cases. At ?rst there is no pain, but in time shooting and throbbing pains usually develop.

Prevention This consists of wearing the right clothing and never venturing on even quite short expeditions in cold weather, particularly on mountains, without taking expert advice as to what should be worn.

Treatment Frostnip is the only form of frostbite that should be treated on the spot. As it usually occurs on exposed parts, such as the face, each member of the party should be on the lookout for it in another. The moment that whitening of the skin is seen, the individual should seek shelter and warm the affected part by covering it with his or her warm hand or a glove until the normal colour and consistency of the affected part are restored. In more severe cases, treatment should only be given in hospital or in a well-equipped camp. In essence this consists of warming the affected part, preferably in warm water, against a warm part of the body or warm air. Rewarming should be done for spells of 20 minutes at a time. The affected part should never be placed near an open ?re. Generalised warming of the whole body may also be necessary, using hot drinks, and putting the victim in a sleeping bag.... frostbite

A. Juss.

Synonym: Melia dubia Cav.

Family: Meliaceae.

Habitat: Native to South Africa. Planted in forest nurseries and plantation at Pune and Vada (Maharashtra).

English: African Mahogany.

Action: Anti-inflammatory, cardiogenic.

Methanolic extract of the stem bark showed cardiovascular (cardiogenic) effect in rodents by increasing blood pressure and vasoconstriction of the arota partly due to the stimulation of beta-receptors and alpha-adreno- ceptors.

Alcoholic extract of the stem bark showed anti-inflammatory activity... khaya senegalensis

Those natural substances, so-called because they were ?rst discovered in the SEMEN and thought to arise in the PROSTATE GLAND, are a group of fatty-acid substances with a wide range of activity. The richest known source is semen, but they are also present in many other parts of the body. Their precise mode of action is not yet clear, but they are potent stimulators of muscle contraction and they are also potent VASODILATORS. They cause contraction of the UTERUS and have been used to induce labour (see PREGNANCY AND LABOUR); they are also being used as a means of inducing therapeutic abortions (see ABORTION).

Prostaglandins play an important part in the production of PAIN, and it is now known that ASPIRIN relieves pain by virtue of the fact that it prevents, or antagonises, the formation of certain prostaglandins. In addition, they play some, although as yet incompletely de?ned, part in producing in?ammatory changes. (See INFLAMMATION; NON-STEROIDAL ANTIINFLAMMATORY DRUGS (NSAIDS).)

Thus prostaglandins have potent biological effects, but their instability and rapid metabolism make them short-acting. They are produced but not stored by most living cells and act locally. The two most important prostaglandins are prostacycline and thromboxane: prostacycline is a vasodilator and an inhibitor of platelet aggregation; thromboxanes have the opposite effects and cause vasoconstriction and platelet aggregation. The NSAIDs act by blocking an ENZYME called cyclo-oxygenase which converts arachidonic acid to the precursors of the various prostaglandins. Despite their potent pharmacological properties, the role of prostaglandins in current therapeutics is limited and controversial. They have been used most successfully as an inhibitor of platelet aggregation in extra-corporeal haemoperfusion systems. The problems with the prostacyclines is that they have to be given intravenously as they are inactive by mouth, and continuous infusion is required because the drug is rapidly eliminated with a half-life of minutes. Side-effects tend to be severe because the drug is usually given at the highest dose the patient can tolerate. The hope for the future lies in the exploitation of the compound to generate, synthetically, stable orally active prostacycline analogues which will inhibit platelet aggregation and hence thrombotic events, and yet have minimal effects on the heart and blood vessels.... prostaglandins

n. an increase or decrease in the diameter of blood vessels, particularly the arteries. See vasoconstriction; vasodilatation.... vasomotion

Benth. ex C. B. Clarke

Family: Umbelliferae; Apiaceae.

Habitat: Jammu and Kashmir at altitudes of 2,500 to 3,500 m.

Ayurvedic: Bhuutakeshi. Selinum sp. are also known as Bhuutakeshi.

Action: Used for mental disorders as a tranquilizer. Volatile oil— hypotensive.

The volatile oil, distilled from the root, contains alpha-and beta-pinene, myrcene, limonene, p-cymene, beta- phellandrene (major constituent), fen- chone, fenchyl alcohol and acetate, fenchyl hydroxy cinnamate, osthol, p- hydroxy cinnamate (0.1%), sesibricin, imperatorin and bergapten.

The volatile oil from aerial parts causes a fall in blood pressure, vasoconstriction and stimulation of respiration. The action appears to be tranquillizing. It potentiates the effects of pentobarbital in rats and has no an- ticonvulsant activity. Smooth muscle activity is inhibited by the oil and negative inotropic and chronotropic effects are observed on heart muscle.... seseli sibiricum

A state of acute circulatory failure in which the heart’s output of blood is inadequate to provide normal PERFUSION of the major organs. It is accompanied by a fall in arterial blood pressure and is characterised by systemic arterial hypotension (arterial blood pressure less than 80 mm of mercury), sweating and signs of VASOCONSTRICTION (for example, pallor, CYANOSIS, a cold clammy skin and a low-volume pulse). These signs may be associated with clinical evidence of poor tissue perfusion, for example to the brain and kidneys, leading to mental apathy, confusion or restlessness and OLIGURIA.

Shock may result from loss of blood or plasma volume. This may occur as a result of haemorrhage or severe diarrhoea and vomiting. It may also result from peripheral pooling of blood due to such causes as TOXAEMIA or ANAPHYLAXIS. The toxaemia is commonly the result of a SEPTICAEMIA in which leakage through capillaries reduces circulating blood volume. Another form is called cardogenic shock, and is due to failure of the heart as a pump. It is most commonly seen as a result of myocardial infarction (see under HEART, DISEASES OF).

If failure of adequate blood ?ow to vital organs is prolonged, the effects can be disastrous. The ischaemic intestine permits the transfer of toxic bacterial products and proteins across its wall into the blood; renal ISCHAEMIA prevents the maintenance of a normal electrolyte and acid-base balance.

Treatment If the shock is a result of haemorrhage or diarrhoea or vomiting, replacement of blood, lost ?uid and electrolytes is of prime importance. If it is due to septicaemia, treatment of the infection is of paramount importance, and in addition, intravenous ?uids and vasopressor drugs will be required. Cardiogenic shock is treated by attention to the underlying cause. Full intensive care is likely to be required, and arti?cial ventilation and DIALYSIS may both be needed.... shock

impairment of renal function, which can occur in acute or chronic liver disease. The condition is associated with intrarenal vasoconstriction and extrarenal vasodilation and hypotension, and the kidney disease is functional rather than structural in nature. There are two common clinical presentations. An acute form (type 1) is characterized by rapid spontaneous deterioration in renal function against a background of acute liver failure, acute alcoholic hepatitis, or acute decompensation of chronic cirrhotic liver disease. A chronic form (type 2) is characterized by insidious onset and slowly progressive deterioration in renal function. This is most often observed in patients with decompensated cirrhosis and portal hypertension. The prognosis of hepatorenal syndrome is extremely poor, and the best hope of survival is usually with liver transplantation.... hepatorenal syndrome