Activity of catecholamine enzymes in vas deferens during nerve stimulation

Bhagat, B.; Dave, Tina K; Lee, Gary; Bryan, RJ

doi:10.1152/ajplegacy.1973.224.1.46

Cited by 2 publications

(1 citation statement)

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“…Most studies [Alousi and Weiner, 1966;Bhagat et al, 1973] indicate that catecholamine concentrations in adrenergically innervated tissues do not change even under conditions of prolonged sympathetic stimulation, provided adequate perfusion is maintained. However, a decrease in catecholamine content has been demonstrated in spleens of cats subjected to surgical stress [Brown et at., 1967], Brown's group also reported an increase in catecholamine levels of decentralized spleens, i.e.…”

Section: Discussionmentioning

confidence: 99%

Effects of Prolonged Hemorrhagic Hypotensive Stress on Catecholamine Concentration of Mesenteric Blood Vessels

Lombard¹,

Loegering²,

Stekiel³

1977

J Vasc Res

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Norepinephrine (NE) and epinephrine (E) concentrations were determined fluorometrically as an index of functional adrenergic innervation in small mesenteric arteries, veins, and superior mesenteric arteries of dogs and rats subjected to a period of prolonged hemorrhage at a constant mean arterial pressure of 35 mm Hg. In nonhemorrhaged animals, highest catecholamine concentrations were found in the small principal arteries, next highest in the small veins, and least in superior mesenteric arteries. A significant decrease occurred in the NE and E concentrations of all three vessel types in the dog during the decompensatory phase of the hypotensive stress (defined as the hypotensive period beyond the time at which maximum bleedout volume occurred). In the rat significant decreases were detectable only in the NE concentrations of the small arteries and veins during this phase. It is concluded that the increase in neurogenic vascular tone accompanying severe hemorrhagic stress is lost simultaneously on the arterial and venous sides of compensatory vascular beds. Such loss is closely related to transmitter depletion at the adrenergic neuromuscular junction and, if allowed to continue uncorrected, can contribute significantly to irreversible cardiovascular collapse.

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Section: Discussionmentioning

confidence: 99%

Effects of Prolonged Hemorrhagic Hypotensive Stress on Catecholamine Concentration of Mesenteric Blood Vessels

Lombard¹,

Loegering²,

Stekiel³

1977

J Vasc Res

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Golden Hamster Pancreatic Islets: A Tissue Rich in Monoamine Oxidase*

1980

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We compared the steady state monoamine oxidase (MAO) activity of collagenase-isolated pancreatic islets of the golden hamster with the steady state MAO activity of liver, kidney, median eminence, pituitary, acinar pancreas, and cerebral cortex. The MAO activity of the islets (5384 +/- 412 pmol/mg protein . min) was 3-fold greater than the activity of the next highest tissue (liver) and 12.5 times greater than the activity of the acinar pancreas. This high MAO activity was not due to collagenase exposure. The islet MAO was mainly of the so-called type B, although there was also some type A activity in this tissue. By assaying the formation of new islet MAO after the irreversible activation of MAO by the MAO inhibitor pargyline, we found that the t 1/2 of islet MAO (5.9 days with 95% confidence limits of 4.1-10.5 days) did not differ from the t 1/2 of MAO in tissues with lower steady state MAO activities. This suggested that the high steady state MAO activity in golden hamster islets is due to a high rate of synthesis rather than to a lower rate of degradation. Although rats, Chinese hamsters, guinea pigs, mice, and rabbits had substantial MAO activity in their pancreatic islets, their levels, at most, were only 16% that of the golden hamster. When the MAO activity of golden hamster islets was inhibited by the administration of pargyline plus clorgyline, there was a 3-fold increase in islet serotonin concentration, with no increase in islet norepinephrine concentration, suggesting that islet MAO activity plays a role in regulating islet serotonin concentration.

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Activity of catecholamine enzymes in vas deferens during nerve stimulation

Cited by 2 publications

References 0 publications

Effects of Prolonged Hemorrhagic Hypotensive Stress on Catecholamine Concentration of Mesenteric Blood Vessels

Effects of Prolonged Hemorrhagic Hypotensive Stress on Catecholamine Concentration of Mesenteric Blood Vessels

Golden Hamster Pancreatic Islets: A Tissue Rich in Monoamine Oxidase*

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