Somatic nerve stimulation evokes qualitatively different somatosympathetic responses in the cervical and splanchnic sympathetic nerves in the rat

2008 ◽  
Vol 1217 ◽  
pp. 139-147 ◽  
Author(s):  
Simon McMullan ◽  
Karrnan Pathmanandavel ◽  
Paul M. Pilowsky ◽  
Ann K. Goodchild
1977 ◽  
Vol 233 (6) ◽  
pp. H647-H654 ◽  
Author(s):  
P. D. Richardson ◽  
P. G. Withrington

The hepatic arterial vascular bed of the chloaralose-urethan-anesthetized dog was perfused with blood from a cannulated femoral artery. Hepatic arterial blood flow and perfusion pressure were measured. The hepatic periarterial postganglionic sympathetic nerves were stimulated supramaximally at 0.1, 0.5, 1, 2, 5, 10, and 20 Hz; this caused frequency-dependent rises in the calculated hepatic arterial vascular resistance at all frequencies above the threshold of 0.1 or 0.5 Hz. Glucagon was infused intra-arterially in dosese from 0.25 to 10 microgram/min; glucagon antagonized both the vasoconstrictor effects of hepatic nerve stimulation and of intra-arterial injections of norepinephrine. The degree of antagonism of these responses was significantly correlated with the calculated hepatic arterial glucagon concentration. It is possible that glucagon released physiologically in stress and hypoglycemia may protect the hepatic arterial vasculature from the effects of increased sympathetic discharge.


1965 ◽  
Vol 209 (2) ◽  
pp. 376-382 ◽  
Author(s):  
Larry A. Rogers ◽  
Richard A. Atkinson ◽  
John P. Long

An isolated preparation of the dog's mesenteric artery with branching small resistance vessels and sympathetic nerves attached has been devised. The branching arterial segments were perfused by a constant-flow technique; the pressor responses to intra-arterially injected catecholamine and to nerve stimulation were recorded. The preparation gave reproducible pressor responses to injected catecholamine and to nerve stimulation for periods of several hours. Decreasing the temperature or increasing the pH (by decreasing CO2 in the gas mixture) of the vessel bath increased arterial smooth muscle tone and potentiated the pressor responses to injected catecholamine and to nerve stimulation. Increasing the temperature of the bath decreased the tone and reactivity of this preparation. Low-frequency continuous nerve stimulation potentiated the responses of this preparation to intra-arterially injected catecholamines.


1990 ◽  
Vol 258 (3) ◽  
pp. E436-E444 ◽  
Author(s):  
B. E. Dunning ◽  
P. J. Havel ◽  
R. C. Veith ◽  
G. J. Taborsky

To address the hypothesis that the neutropeptide, galanin, functions as a sympathetic neurotransmitter in the endocrine pancreas, we sought to determine if galanin is released from pancreatic sympathetic nerves during their direct electrical stimulation in halothane-anesthetized dogs. During bilateral thoracic splanchnic nerve stimulation (BTSNS), both peripheral arterial and pancreatic venous levels of galanin-like immunoreactivity (GLIR) increased (delta at 10 min = +92 +/- 31 and +88 +/- 25 fmol/ml, respectively). Systemic infusions of synthetic galanin demonstrated that 1) the increment of arterial GLIR observed during BTSNS was sufficient to modestly restrain basal insulin secretion and 2) only 25% of any given increment of arterial GLIR appears in the pancreatic vein, suggesting that the pancreas extracts galanin, as it does other neurotransmitters. By use of 75% for pancreatic extraction of circulating galanin, it was calculated that pancreatic galanin spillover (output) increased by 410 +/- 110 fmol/min during BTSNS. To reinforce the conclusion that pancreatic sympathetic nerves release galanin, GLIR spillover was next measured during direct local stimulation of the pancreatic sympathetic input produced by electrical stimulation of the mixed autonomic pancreatic nerves (MPNS) in the presence of the ganglionic blocker, hexamethonium. During this local pancreatic sympathetic nerve stimulation, arterial GLIR remained unchanged, but pancreatic venous GLIR increased by 123 +/- 34 fmol/ml. Thus pancreatic GLIR spillover increased by 420 +/- 110 fmol/min during MPNS in the presence of hexamethonium. We conclude that galanin is released from both pancreatic and extrapancreatic sources during sympathetic neural activation in dogs.


2018 ◽  
Vol 114 (suppl_1) ◽  
pp. S110-S110
Author(s):  
K H Lee ◽  
H N Cho ◽  
S R Lee ◽  
SM K Lee ◽  
W Kim

1996 ◽  
Vol 271 (2) ◽  
pp. H630-H636 ◽  
Author(s):  
X. J. Du ◽  
E. Vincan ◽  
D. M. Woodcock ◽  
C. A. Milano ◽  
A. M. Dart ◽  
...  

Transgenic mice have been created with 200-fold overexpression of beta 2-adrenergic receptors specifically in the heart. Cardiac function was studied in these transgenic mice and their controls at baseline and during isoproterenol perfusion or sympathetic nerve stimulation. The model used was an in situ buffer-perfused, innervated heart, and the left ventricle maximal derivative of pressure over time (dP/dtmax) and heart rate (HR) were measured. Basal HR and dP/dtmax were 30-40% higher in hearts from transgenic mice than controls. Electrical stimulation of sympathetic nerves (2, 4, and 8 Hz) or infusion of isoproterenol markedly increased HR and dP/dtmax in control hearts. Hearts from transgenic mice did not respond to isoproterenol. However, hearts from transgenic mice retained the HR response to nerve stimulation, and a small increase in dP/dtmax was also detected. Atenolol inhibited the response to nerve stimulation in control hearts but not that in hearts from transgenic mice. ICI-118551 inhibited the response in transgenic hearts. Basal HR and dP/dtmax were decreased by ICI-118551 only in transgenic hearts. Thus overexpression of cardiac beta 2-receptors modifies beta-adrenergic activity, but the responses to endogenous and exogenous adrenergic stimulation are affected differently.


1993 ◽  
Vol 264 (3) ◽  
pp. H892-H900 ◽  
Author(s):  
L. R. Dodd ◽  
P. C. Johnson

It has been suggested that muscle contraction causes prejunctional inhibition of transmitter release from sympathetic nerves. In accordance with this, we found that second-order (50 microns ID) arterioles of the cat sartorius muscle dilate 40-80% more with muscle contraction during 2-, 4-, or 8-Hz sympathetic nerve stimulation than during equivalent constriction produced by intravenous norepinephrine injection. However, when constriction was to the selective alpha 1-agonist phenylephrine, the magnitude of dilation induced by muscle contraction was similar to that seen with sympathetic nerve stimulation, suggesting that prejunctional inhibition is not involved. Alternatively, different receptor subtypes may be activated by sympathetic nerve stimulation and exogenous norepinephrine. In support of this explanation, we found that approximately 50% of the vasoconstrictor effect of sympathetic nerve stimulation (8 Hz) was blocked by prazosin, an alpha 1-adrenergic antagonist, but no further diminution of tone was seen with addiction of yohimbine, an alpha 2-adrenergic antagonist. In contrast, the vasoconstrictor response to exogenous norepinephrine was not affected by prazosin, while addition of yohimbine almost completely blocked the response. These findings suggest that muscle contraction selectively attenuates vasoconstriction mediated by junctional receptors in second-order arterioles.


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