Inhibitory effect of GABA on phrenic discharge activity of rabbit through microinjection into nucleus tractus solitarii

1985 ◽  
Vol 5 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Cheng-jun Huang ◽  
Jian-zhong Xiang
Keyword(s):  
Inhibitory Effect ◽  
Nucleus Tractus Solitarii ◽  
Discharge Activity

Role of serotonin3 receptors in the nucleus tractus solitarii on the carotid chemoreflex

1997 ◽  
Vol 272 (3) ◽  
pp. H1250-H1259 ◽  
Author(s):  
C. Sevoz ◽  
J. C. Callera ◽  
B. H. Machado ◽  
M. Hamon ◽  
R. Laguzzi
Keyword(s):  
Inhibitory Effect ◽  
Nucleus Tractus Solitarii ◽  
Inhibitory Influence ◽  
Dependent Manner ◽  
Gamma Aminobutyric Acid ◽  
Receptor Stimulation ◽  
Gaba A ◽  
Anesthetized Rats ◽  
Carotid Body Chemoreceptors ◽  
Spontaneously Breathing

The effects of serotonin3 (5-HT3)-receptor stimulation in the nucleus tractus solitarii (NTS) on the cardiovagal, sympathetic, and respiratory responses to activation of carotid body chemoreceptors were investigated in anesthetized rats. The chemoreflex responses were triggered by an intravenous administration of KCN (40 microg/kg) in spontaneously breathing urethan-chloralose-anesthetized rats or by an intracarotid administration of saline saturated with 100% CO2 in pancuronium bromide-paralyzed and artificially ventilated urethan-anesthetized rats. Microinjections of 5-HT (2.5-5 nmol) or the 5-HT3 agonist 1-(m-chlorophenyl)-biguanide (CPBG, 300-1,200 pmol) into the commissural NTS blocked in a dose-dependent manner the atropine-sensitive chemoreflex bradycardia elicited by KCN. However, neither 5-HT nor CPBG affected the KCN-induced increase in respiratory volume and the CO2-induced increases in blood pressure and lumbar sympathetic nerve discharge. The inhibitory effect of 5-HT or CPBG on KCN-induced bradycardia was blocked by prior intra-NTS microinjection of a 5-HT3 antagonist, such as zacopride (100 pmol) or ondansetron (100 pmol), or the A-type gamma-aminobutyric acid (GABA(A)) antagonist bicuculline (10 pmol). In contrast, local microinjections of antagonists acting at 5-HT1 and 5-HT2 receptors, such as methysergide (100 pmol) and ketanserin (10 pmol), respectively, did not prevent the actions of 5-HT or CPBG. These data show that the stimulation of 5-HT3 receptors in the NTS exerted an inhibitory influence, probably through the activation of a local GABAergic system, on the cardiovagal component of the chemoreflex. Because similar effects of 5-HT3-receptor stimulation in the NTS were previously found on the baroreflex and Bezold-Jarisch reflex responses, it can be inferred that NTS 5-HT3 receptors play a key modulatory role in the reflex control of the heart rate.

scholarly journals Ventilatory effects of substance P-saporin lesions in the nucleus tractus solitarii of chronically hypoxic rats

2011 ◽  
Vol 301 (2) ◽  
pp. R343-R350 ◽  
Author(s):  
Katherine A. Wilkinson ◽  
Zhenxing Fu ◽  
Frank L. Powell
Keyword(s):  
Substance P ◽  
Chronic Hypoxia ◽  
Acute Hypoxia ◽  
Inhibitory Effect ◽  
Nucleus Tractus Solitarii ◽  
Neurokinin 1 Receptor ◽  
Ventilatory Responses ◽  
Ventilatory Drive ◽  
Ventilatory Effects ◽  
Neurokinin 1

During ventilatory acclimatization to hypoxia (VAH), time-dependent increases in ventilation lower Pco2 levels, and this persists on return to normoxia. We hypothesized that plasticity in the caudal nucleus tractus solitarii (NTS) contributes to VAH, as the NTS receives the first synapse from the carotid body chemoreceptor afferents and also contains CO2-sensitive neurons. We lesioned cells in the caudal NTS containing the neurokinin-1 receptor by microinjecting the neurotoxin saporin conjugated to substance P and measured ventilatory responses in awake, unrestrained rats 18 days later. Lesions did not affect hypoxic or hypercapnic ventilatory responses in normoxic control rats, in contrast to published reports for similar lesions in other central chemosensitive areas. Also, lesions did not affect the hypercapnic ventilatory response in chronically hypoxic rats (inspired Po2 = 90 Torr for 7 days). These results suggest functional differences between central chemoreceptor sites. However, lesions significantly increased ventilation in normoxia or acute hypoxia in chronically hypoxic rats. Hence, chronic hypoxia increases an inhibitory effect of neurokinin-1 receptor neurons in the NTS on ventilatory drive, indicating that these neurons contribute to plasticity during chronic hypoxia, although such plasticity does not explain VAH.

Inhibitory effect of melatonin on nitric oxide synthase in rat enteric nervous system

2001 ◽  
Vol 120 (5) ◽  
pp. A176-A176
Author(s):  
P KOPPITZ ◽  
M STORR ◽  
D SAUR ◽  
M KURJAK ◽  
H ALLESCHER
Keyword(s):  
Nitric Oxide ◽  
Nervous System ◽  
Nitric Oxide Synthase ◽  
Enteric Nervous System ◽  
Inhibitory Effect ◽  
Oxide Synthase

Inhibitory effect of proton pump inhibitors against chemotaxis of Helicobacter pylori

2001 ◽  
Vol 120 (5) ◽  
pp. A655-A656
Author(s):  
H NAKAMURA ◽  
H YOSHIYAMA ◽  
H YANAI ◽  
M SHIRAL ◽  
T NAKAZAWA ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Proton Pump Inhibitors ◽  
Proton Pump ◽  
Inhibitory Effect

The Nature of the Inhibitory Effect of Normal Human Gastric Jiuice on Heidenhain Pouch Dogs

1958 ◽  
Vol 34 (2) ◽  
pp. 181-187 ◽  
Author(s):  
William O. Smith ◽  
Robert Hoke ◽  
Jerome Landy ◽  
Ranwel Caputto ◽  
Stewart Wolf
Keyword(s):  
Inhibitory Effect ◽  
Heidenhain Pouch ◽  
Normal Human

Inhibitory effect of Rhamnus alpinus and Rhamnus saxatilis extracts on chemokine secretion induced by lipopolysaccharide in monocyte-derived macrophages

Planta Medica ◽  
2008 ◽  
Vol 74 (09) ◽  
Author(s):  
F Epifano ◽  
L Menghini ◽  
A Chiavaroli ◽  
G Orlando ◽  
VD La ◽  
...  
Keyword(s):  
Inhibitory Effect
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