Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.36 (hyaluronidase)
 4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Digestion of human foreskin with collagenase and hyaluronidase disperses approximately 3.4 X 10(7) nucleated cells per gram of tissue, of which mast cells constitute 4.7%. These may be purified to 80% by use of density gradient centrifugation. The majority of mast cells (79%) measured between 9 and 13 micron in diameter, and the mean histamine content was 4.6 pg/cell. Viability was demonstrated by trypan blue exclusion by 93% of the cells and the low spontaneous histamine secretion of less than 7% in functional studies. Anti-IgE released up to 17.5% of cell-associated histamine within 5 to 7 min. Calcium ionophore-induced release was optimal with 0.3 microM A23187 when 28.6% histamine was released. Unlike human lung mast cells, skin mast cells released histamine in response to compound 48/80 and poly-L-lysine. This release, which was complete within 20 sec, was totally dependent on intact glycolysis and oxidative phosphorylation and partially dependent on extracellular calcium. The same characteristics were observed with secretion induced by substance P and morphine. The weak activity of eledoisin and physalaemin suggests that the substance P receptor, like that of the rat mast cell, is not of the classical types described for smooth muscle. Morphine-induced secretion was partially blocked by naloxone in a manner not compatible with competitive antagonism at a classical opioid receptor. The sensitivity of skin mast cells to nonimmunologic stimulation clearly distinguishes them from mast cells of the lung and lymphoid tissues and provides evidence of functional heterogeneity within human mast cells.
 ...
PMID:Human skin mast cells: their dispersion, purification, and secretory characterization. 243 32

The recognition and alleviation of animal pain is a growing veterinary and public concern. Pain can be of an acute or chronic nature with different behavioral manifestations. Physiologically, pain is a dynamic and complex phenomenon that produces changes in the central and autonomic nervous systems as well as in the endocrine system. Horses and other animals appear to possess an endogenous pain-suppressing system involving the brainstem and spinal cord. This system can modulate pain perception and the responses to it. The recently discovered endogenous opioid peptides (endorphins and enkephalins) appear to play a role in this system, which is activated by stress. Opioids (narcotic analgesics) act to selectively depress pain-sensitive cells. Opioid analgesics may act via multiple opioid receptors. Each subclass of opioid receptor has a different pharmacologic profile. Classical opioids that act at mu (morphine) receptors typically produce analgesia, increased locomotor activity, cardiorespiratory stimulation, and a decrease in intestinal peristalsis in the horse. Opioids that act at kappa receptors produce analgesia, sedation, ataxia, and minimal autonomic effects in the horse. Owing to their lack of excitatory actions, the kappa opioids represent a potentially useful class of analgesics for use in equine species. Local anesthetics depress all excitable cells and can diminish sensory, motor, and muscular function. They do not act selectively on pain fibers, although pain is among the first sensations lost following a nerve block. Local anesthetic activity is enhanced by increased extraneuronal pH, nerve cooling, increased nervous activity, coadministration of a vasoconstrictor or hyaluronidase, delayed systemic absorption, prolonged drug metabolism, and by using agents with high lipid solubility. Procaine, lidocaine, and mepivacaine are among the most widely used and studied agents in horses. These agents and/or their metabolites can be readily detected in urine; in some cases, for prolonged periods.
 ...
PMID:Narcotics and local anesthetics. 829 18