- Author: Johnson Francis
- Filed under: General
- Date: Sep 16,2009
Mannitol being an osmotically active agent draws fluid from the extravascular compartment into the vascular compartment. This causes transient volume expansion and may cause pulmonary edema if the cardiac or renal status is compromised. But if the renal status is good, this extra fluid is soon excreted as mannitol is an osmotic diuretic as well. This property of mannitol is used therapeutically to treat cerebral edema, though caution has to be exercised in those with co-existing renal or cardiac disease.
Decrease blood flow to the kidneys cause them to secrete renin. Renin increases the production of angiotensin, a potent vasoconstrictor (causes contraction of smooth muscles of the blood vessels). Specifically it is angiotensin II which is one of the most potent vasoconstrictors. Renin converts angiotensinogen to angiotensin I, which is converted to angiotensin II by angiotensin converting enzyme (ACE). Angiotensin II stimulates the secretion of aldosterone, a hormone which causes salt and water retention. Aldosterone is secreted from the adrenal cortex. Renin is a proteolytic enzyme secreted by the juxta glomerular apparatus of the kidney. Angiotensinogen is synthesised in the liver.
- Author: Bijoy Johnson
- Filed under: Uncategorized
- Date: Sep 1,2009
Heart patients who become depressed are found to have a higher risk of developing heart failure. Heart disease affects millions of people in the world. In a study conducted on people who had a heart attack, it was found that people were 3 times more likely to develop depression after a heart attack. Also people with depression were more likely to develop a second heart attack.
In the study conducted in about 14000 persons who had a heart attack, it was found that people who developed depression were 4 times more likely to develop heart failure and die than those without depression. Also antidepressants were not found to reverse these effects.
