Catecholamine secretion

Combined Hj /H2 receptor stimulation by histamine is responsible for vasodilation-related symptoms, such as hypotension, flushing, and headache, as well as for tachycardia stimulated indirecdy through vasodilation and catecholamine secretion. 

Pituitary Adenylyl Cyclase-activating Polypeptide (PACAP) is a 38-amino acid peptide (PACAP-38), which is widely expressed in the central nervous system. PACAP is most abundant in the hypothalamus. It is also found in the gastrointestinal tract, the adrenal gland and in testis. Its central nervous system functions are ill-defined. In the periphery, PACAP has been shown to stimulate catecholamine secretion from the adrenal medulla and to regulate secretion from the pancreas. Three G-protein coupled receptors have been shown to respond to PACAP, PAQ (PACAP type I) specifically binds PACAP, VPACi and VPAC2 also bind vasoactive intestinal peptide (VDP). Activation of PACAP receptors results in a Gs-mediated activation of adenylyl cyclase. 

Liu PS, Kao LS, Lin MK. 1994. Organophosphates inhibit catecholamine secretion and calcium influx in bovine adrenal chromaffin cell. Toxicology 90 81-91. 

The major circulating hormones that influence vascular smooth muscle tone are the catecholamines epinephrine and norepinephrine. These hormones are released from the adrenal medulla in response to sympathetic nervous stimulation. In humans, 80% of catecholamine secretion is epinephrine and 20% is norepinephrine. Stimulation of cy-adrenergic receptors causes vasoconstriction. The selective a,-adrenergic receptor antagonist, prazosin, is effective in management of hypertension because it causes arterial and venous smooth muscle to relax. 

Matsuzawa, A., Makoto, M., Atsumi, G. et al. Release of secretory phosphohpase A2 from rat neuronal cells and its possible function in the regulation of catecholamine secretion. Biochem. J. 318,701-709,1996. 

Hypertension infrequently results from another disease, such as a catecholamine-secreting tumor (pheochro-mocytoma) in most cases the cause carmot be determined essential (primary) hypertension. Antihypertensive drugs are indicated when blood pressure cannot be sufficiently controlled by means of weight reduction or a low-salt diet. In principle, lowering of either cardiac output or peripheral resistance may decrease blood pressure (cf p. 306,... 

URINE EXTRACTION. Neonatal urine (15 cm3 if the 24-hr volume was greater than 100 cm3 or 10 cm3 if less), normal adult urine (10 cm3), or urine of patients with suspected catecholamine secreting... 

Taylor, S. C., Batten, T. F., and Peers, C. (1999). Hypoxic enhancement of quantal catecholamine secretion. Evidence for the involvement of amyloid beta-peptides. J Biol Chem 274, 31217—31222. 

Mahata M, Mahata SK, Parmer RJ, O Connor DT (1996) Vesicular monoamine transport inhibitors. Novel action at calcium channels to prevent catecholamine secretion. Hypertension 28 414 120. 

Koh DS, Hille B (1997) Modulation by neurotransmitters of catecholamine secretion from sympathetic ganglion neurons detected by amperometry. Proc Natl Acad Sci USA 94 1506-11 Koh TW, Bellen HJ (2003) Synaptotagmin I, a Ca2+ sensor for neurotransmitter release. Trends Neurosci 26 413-22... 

Paclitaxel 1 microM 2 6149300 1 taxol inhibits acetylcholine-stimulated catecholamine secretion (IC50 2... 

Neurotensin-induced adrenal chromaffin cell catecholamine secretion] NEUT-R antagonist (CPA) [inhibits mast cell Histamine release]... 

Histamine, serotonin and the catecholamines (dopamine, epinephrine and norepinephrine) are synthesized from the aromatic amino acids histidine, tryptophan and phenylalanine, respectively. The biosynthesis of catecholamines in adrenal medulla cells and catecholamine-secreting neurons can be simply summarized as follows [the enzyme catalysing the reaction and the key additional reagents are in square brackets] phenylalanine — tyrosine [via liver phenylalanine hydroxylase + tetrahydrobiopterin] —> i.-dopa (l.-dihydroxyphenylalanine) [via tyrosine hydroxylase + tetrahydrobiopterin] —> dopamine (dihydroxyphenylethylamine) [via dopa decarboxylase + pyridoxal phosphate] — norepinephrine (2-hydroxydopamine) [via dopamine [J-hydroxylasc + ascorbate] —> epinephrine (jV-methyl norepinephrine) [via phenylethanolamine jV-methyltransferase + S-adenosylmethionine]. 

Dar, D.E., and Zinder, O. 1998. Catecholamine secretion from bovine adrenal chromaffin cells induced by the dextrorotatory isomer of anatoxin-a. Gen Pharmacol 31, 737-740. 

Systemic Effects. The use of 1,1-dichloroethane as an anesthetic was discontinued when it was discovered that this compound induced cardiac arrhythmias in humans at anesthetic doses (approximately 105,000 mg/m, or 26,000 ppm). The mechanism of action for the induction of cardiac arrhythmias by 1,1-dichloroethane is not known. However, when the cardiac muscle is markedly depressed, it is more susceptible to the effects of catecholamines. Secretion of catecholamines is increased in this situation by compensatory and other mechanisms, resulting in excessive spontaneous contractions of the heart. This is an effect common to exposure to other chlorinated aliphatics at high concentrations (Reinhardt et al. 1971). Cardiovascular toxicity has not been reported in animals following exposure to 1,1-dichloroethane. 

Leszczyszyn DJ, Jankowski JA, Viveros OH, Diliberto EJ Jr., Near JA, Wightman RM. Nicotinic receptor-mediated catecholamine secretion from individual chromaffin cells. Chemical evidence for exocytosis. J. Biol. Chem. 1990 265 14736-14737. 

A study in which a number of head injury patients were divided into groups depending on the severity of the injury showed a smaller rise in insulin levels in the first 3-5 days in the more severely injured. This fall in insulin levels as the severity of injury increases is probably related to catecholamine secretion. A decreased insulin response has also been observed following cardiogenic shock (D2) and hemorrhagic shock (B3). 

Some common activities, such as mental effort (347), cigarette smoking, and coffee drinking (348,349), can produce stress associated with increased catecholamine secretion. In the presence of a non-selective beta-adreno-ceptor antagonist, there can be a marked diastolic pressor response, due to mechanisms identical to those described above in hypoglycemia in diabetes. This effect may be smaller with cardioselective drugs. 

Ahnert-Hilger G, Bader MF, BhakDai S et al. (1989b) Introduction of macromolecules into bovine adrenal medullary chromaffin cells and rat pheochromocy-toma cells (PC12) by permeabilization with streptolysin O inhibitory effect of tetanus toxin on catecholamine secretion. J. Neurochem. 52 1751 -8... 

Camphor inhibited catecholamine secretion from bovine adrenal chromaffin cells. 

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