Multiple Mechanisms in Ganglionic Transmission

Author(s):  
N. J. Dun ◽  
A. G. Karczmar
1987 ◽  
Vol 103 (5) ◽  
pp. 299-302
Author(s):  
Tadahiko Hoshino ◽  
Nobuo Usui

2013 ◽  
Vol 305 (3) ◽  
pp. H403-H409 ◽  
Author(s):  
Amanda L. Sharpe ◽  
Mary Ann Andrade ◽  
Myrna Herrera-Rosales ◽  
Steven L. Britton ◽  
Lauren G. Koch ◽  
...  

Exposure to chronic intermittent hypoxia (CIH) is an animal model that mimics the repetitive bouts of hypoxemia experienced by humans with sleep apnea. Rats exposed to CIH develop hypertension that depends on the activation of sympathetic nerve activity (SNA). Since obesity and metabolic syndrome have been linked to neurogenic hypertension and sleep apnea, and because sleep apnea can adversely affect aerobic exercise capacity, we tested the hypothesis that rats bred for selection of low aerobic capacity running (LCR) would have a greater hypertensive response to CIH than rats bred for high aerobic capacity running (HCR). Blockade of ganglionic transmission was performed to compare the contribution of SNA to the maintenance of resting mean arterial pressure (MAP). Next, hypertensive responses to 7 days of CIH were compared across LCR and HCR rats (14–16 mo old). Finally, the contribution of the hypothalamic paraventricular nucleus (PVN) to the maintenance of SNA and hypertension after CIH was determined and compared across groups. Although LCR rats were less active and had greater body weights than HCR rats, resting MAP, the contribution of ongoing SNA to the maintenance of MAP, and hypertensive responses to CIH were similar between groups. Contrary to our hypothesis, chemical inhibition of the PVN with muscimol (1 mmol/100 nl) caused a larger fall of MAP in HCR rats than in LCR rats. We conclude that LCR rats do not have resting hypertension or an exaggerated hypertensive response to CIH. Interestingly, the maintenance of CIH hypertension in LCR rats compared with HCR rats appears less reliant on ongoing PVN neuronal activity.


1992 ◽  
Vol 70 (S1) ◽  
pp. S2
Author(s):  
Peter A. Smith ◽  
William F. Dryden ◽  
Canio Polosa ◽  
Vladimir I. Skok

Over the last 20 years there has been a marked increase in the understanding of the biophysical properties of neurones in autonomic ganglia. During the same time period, there have been advances in immunohistochemistry which have shown that the autonomic ganglia are rich sources of a variety of neuroactive peptides and monoamines. Although physiological studies have underlined the role of enteric and prevertebral ganglia in the control of peristalsis and micturition, very little is known about the physiological role of many of the other autonomic ganglia.The objective of the International Brain Research Organization satellite symposium held in Edmonton, Alberta, during August 1991, was to bring together the biophysicists, morphologists, physiologists, and pharmacologists to evaluate the current status of our understanding of the autonomic ganglia. Posters and four sessions of invited talks were presented over a three-day period. The papers that appear in this issue detail the content of some of these talks.The organizers gratefully acknowledge the financial support provided by the Alberta Heritage Foundation for Medical Research, the Medical Research Council of Canada, Astra Pharma Inc., the University of Alberta Conference Fund, Nordic Laboratories, Merck Frosst Canada, Axon Instruments, Novopharm Ltd., Bio-Méga Inc., Chembiomed, Newport Instruments, the City of Edmonton, Charles River Canada, and Mandel Scientific.


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