Adrenaline secretion

Although no free epinephrine is excreted under the conditions of those experiments just described, it is permissible to question whether they are representative of the fate of epinephrine as it is secreted in the body, or whether conjugation is a mode of inactivation of catechol pressor amines administered as drugs. The relatively minute amounts of adrenaline or noradrenaline secreted normally and the limitations of present analytical methods definitely handicap a direct approach to the problem. However, it has been possible to study the fate of adrenaline secreted by the body in a more or less physiological type of experiment. 

These latter, involuntary effectors are controllable not directly, but through intermediates. I cannot directly increase the amount of adrenaline in my bloodstream, for example, but if I make myself angry and wave my fists and shout and holler, I will almost certainly increase the amount of adrenaline secreted. 

The Motor Output subsystem consists of those structures which we physically affect the external world and our own bodies. In terms of conscious awareness, these structures are primarily the skeletal, voluntary musculature. If I take a minute out from writing to pet my cat, I am using my Motor Output subsystem with full awareness. The Motor Output subsystem elements that primarily affect our own bodies are glandular secretions and other internal, biological processes. These latter, involuntary effectors are controllable not directly, but through intermediates. I cannot directly increase the amount of adrenaline in my bloodstream, for example, but if I make myself angry and wave my fists and shout and holler, I will almost certainly increase the amount of adrenaline secreted. 

Control of blood pressure preoperatively or when the tumour cannot be removed is achieved by a-adrenoceptor blockade which reverses peripheral vasoconstriction. P-blockade may also be required to control tachycardia in patients with adrenaline-secreting tumours. Since adrenaline secretion, as explained above, tends to fall as tumours enlarge, tachycardia is not usually a major problem. Initiation of a-blocker treatment can unmask tachycardia, since there is no longer baroreceptor induced vagal... 

After 5-10 years of diabetes, glucose counter-regulation in IDDM becomes further impaired when adrenaline secretion also becomes deficient. This, however, can be attributed to diabetic autonomic neuropathy, because it is usually accompanied by reduced pancreatic polypeptide response (Cryer, 1983 White et al., 1985a Gerich, 1988). 

Medulla Phaeochromocytoma Excessive adrenaline secretion Surgical removal of adrenal gland... 

Kidokoro Y, Ritchie AK. Chromaffin cell action potentials and their possible role in adrenaline secretion from rat adrenal medulla. J Physiol 1980 307 199-216. 

Hedeland H, Djmling J-F, Holrfelt B. Pharmacological inhibition of adrenaline secretion following insulin induced hypoglycaemia in man the effect of Catapresan. Acta Endocrinol (Copenh) (1971) 67, 97-103. 

Mean urinary adrenaline secretion at various times during the day off and three wQrking days differing in intensity of woric data of 30 driving examiners. Data are from the same study described in Figs. 6.1 and 6.4. 

Hamrin, B., Sustained hypotension and shock due to an adrenaline-secreting phaeochromocytoma, Lancet, 1962, p. 123. 

Oi, Y., Kawada, T., Shishido, C., Wada, K., Kominato, Y., Nishimura, S., Ariga, T., and Iwai, K. 1999. Allyl-containing sulfides in garlic increase uncoupling protein content in brown adipose tissue, and noradrenaline and adrenaline secretion in rats. J Nutr J29(2) 336-342. 

The value of adrenalin secretion in an emergency must therefore remain in some doubt. The glucose shed from the liver into the blood cannot readily be taken up and utilized, and evidently the stimulus to the muscles is mainly, if not wholly, concerned with glycolysis. 

Kobata K. Capsaicinol Synthesis by allylic oxidation and its effect on TRPVl-expressing cells and adrenaline secretion in rats. Bioscience, Biotechnology, and Biochemistry, 70 1904-1912 (2006). 

The means by which cyclic nucleotides exert their influence involves a class of enzymes the protein kinases. As the name implies, these are enzymes that catalyze the phosphorylation of a protein (usually an enzyme) substrate. Just how protein kinases control various processes may be understood by returning to the problem of adrenaline secretion in response to fright. 

The use of a-site blockers in therapy is small compared to that of P-block-ers. Imidazolines, like phentolamine (7.4/) and tolazoline, are mainly a-blockers but have other actions too. The a-site blockers are used principally to restore peripheral circulation, as in frostbite, and to diagnose adrenaline-secreting tumours. 

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