Calcium-mediated neurotoxicity: relationship to specific channel types and role in ischemic damage.

Carnitine was detected at the beginning of this century, but it was nearly forgotten among biochemists until its importance in fatty acid metabolism was established 50 years later. In the last 30 years, interest in the metabolism and functions of carnitine has steadily increased. Carnitine is synthesized in most eucaryotic organisms, although a few insects (and most likely some newborn animals) require it as a nutritional factor (vitamin BT). Carnitine biosynthesis is initiated by methylation of lysine. The trimethyllysine formed is subsequently converted to butyrobetaine in all tissues; the butyrobetaine is finally hydroxylated to carnitine in the liver and, in some animals, in the kidneys (see Fig. 1). It is released from these tissues and is then actively taken up by all other tissues. The turnover of carnitine in the body is slow, and the regulation of its synthesis is still incompletely understood. Microorganisms (e.g., in the intestine) can metabolize carnitine to trimethylamine, dehydrocarnitine (b...

/pdf/carnitine-metabolism-and-functions-19pl58f13m.pdf

Carnitine--metabolism and functions

High density lipoprotein metabolism.

Lipids of mitochondria

Nitric oxide synthase (NOS) produces nitric oxide, a mediator of potential importance in numerous physiologic and inflammatory processes in the lung. We localized constitutive NOS (c-NOS) and inducible NOS (i-NOS) within lung tissue by immunoperoxidase labeling with specific antibodies or by histochemical demonstration of the characteristic NADPH diaphorase activity of NOS. We analyzed human airway (n = 4) or parenchyma (n = 10) specimens obtained from uninvolved areas of surgical tumor resections. We also studied human fetal lung samples (n = 6) and normal or inflamed (16 h after intratracheal LPS instillation) rat lung tissue. Immunostaining with anti-c-NOS identified c-NOS antigen in rat lung nerves, endothelium, and airway epithelium. Normal or inflamed rat macrophages were not stained. Human nerve elements and large-vessel endothelium showed immunostaining with the anti-c-NOS, but no labeling of the airway or alveolar epithelium was seen. Immunostaining with anti-i-NOS showed strong labeling of rat m...

Nitric oxide synthase in human and rat lung: immunocytochemical and histochemical localization.

On the metabolic function of heparin-releasable liver lipase.

Perfusion of isolated rat hearts with a modified Tyrode solution followed by perfusion with a calcium-free perfusate results in an electromechanical dissociation and causes no significant morphological changes. However, reinstitution of calcium ions leads to gross morphological changes, as shown by histological and electron-microscopical evidence. Contractility is not restored and electrical activity disappears (calcium paradox). Some of the cells are reduced to empty spaces containing swollen mitochondria. Other cells appear to be intact, but show signs of hypercontraction. Cardiac damage due to the calcium paradox could also be demonstrated by x-ray angiography.

Willem C. Hülsmann

Papers

On the metabolic function of heparin-releasable liver lipase.

Morphological changes of heart muscle caused by successive perfusion with calcium-free and calcium-containing solutions (calcium paradox)

Heparin-releasable (liver) lipase(s) may play a role in the uptake of cholesterol by steroid-secreting tissues

Metabolic aspects of isolated cells from rat small intestinal epithelium.

Carnitine palmitoyltransferase deficiencies.