scholarly journals Mechanisms of pentazocine-induced ventilatory depression and antinociception in anesthetized rats

2016 ◽  
Vol 130 (3) ◽  
pp. 181-184 ◽  
Author(s):  
Satoko Kimura ◽  
Yoshiaki Ohi ◽  
Akira Haji
Keyword(s):  
Anesthetized Rats ◽  
Ventilatory Depression

Local application of somatostatin in the rat ventrolateral brain medulla induces apnea

1990 ◽  
Vol 69 (6) ◽  
pp. 2233-2238 ◽  
Author(s):  
Z. B. Chen ◽  
T. Hedner ◽  
J. Hedner
Keyword(s):  
Ventrolateral Medulla ◽  
Inhibitory Effects ◽  
Anesthetic Depth ◽  
Anesthetized Rats ◽  
Nucleus Paragigantocellularis ◽  
Local Injections ◽  
Ventilatory Depression ◽  
Dose Dependent ◽  
The Brain ◽  
Dorsal Medulla

Local injections of the tetradecapeptide somatostatin (SOM) into the brain stem region were performed in anesthetized and decerebrate rats. SOM administration (0.6-1.8 nmol) into the nucleus paragigantocellularis and the nucleus reticularis lateralis of the ventrolateral medulla oblongata induced ventilatory depression and apnea. The occurrence of apnea was dose dependent and attributed to the anesthetic depth, and it was seen within 60-240 s after injection. In anesthetized rats the apnea was seen as a termination or a continuous decrease in tidal volume while respiratory frequency remained unaltered. SOM-induced apnea was caused by depression of central inspiratory drive. SOM injections into the dorsal medulla were ineffective in eliciting apnea, although a ventilatory depression but no apnea was induced in the awake unanesthetized state. In addition to its effect on basal ventilation, SOM administration in the ventrolateral medulla resulted in a blunted ventilatory response to hypoxic and hypercapnic stimuli in anesthetized rats. We conclude that SOM has potent inhibitory effects on respiration that are specifically located in the nucleus paragigantocellularis and the nucleus reticularislateralis.

Repinotan, a Selective 5-HT1A-R-Agonist, Antagonizes Morphine-Induced Ventilatory Depression in Anesthetized Rats

2010 ◽  
pp. 1 ◽  
Author(s):  
U. Guenther ◽  
H. Wrigge ◽  
N. Theuerkauf ◽  
M. F. Boettcher ◽  
G. Wensing ◽  
...  
Keyword(s):  
Anesthetized Rats ◽  
Ventilatory Depression

scholarly journals Selective 5-HT1A-R-agonist Repinotan Prevents Remifentanil-induced Ventilatory Depression and Prolongs Antinociception

2012 ◽  
Vol 116 (1) ◽  
pp. 56-64 ◽  
Author(s):  
Ulf Guenther ◽  
Nils U. Theuerkauf ◽  
Daniel Huse ◽  
Michael F. Boettcher ◽  
Georg Wensing ◽  
...  
Keyword(s):  
Minute Ventilation ◽  
Antinociceptive Effect ◽  
Tail Flick ◽  
Moderate Dose ◽  
Pretreatment Level ◽  
Remifentanil Infusion ◽  
Anesthetized Rats ◽  
Small Doses ◽  
Ventilatory Depression ◽  
Spontaneously Breathing

Background 5-HT(1A)-R-agonist repinotan was shown to counteract a morphine-induced ventilatory depression but had pronociceptive effects at small doses (0.2 μg/kg). It remained to be clarified (1) whether a moderate dose of repinotan, sufficient to stimulate spontaneous breathing, impairs antinociception if plasma concentration decreases over time, and if (2) moderate doses prevent ventilatory depression if given before the opioid. Methods A dose-response curve of the repinotan effects on spontaneous minute ventilation during continuous remifentanil infusion in anesthetized rats was established to identify moderate doses: (1) tail-flick reflex latencies to assess nociception were recorded until 60 min after cessation of a continuous remifentanil infusion with or without a concomitant moderate repinotan dose (10 μg/kg), and (2) remifentanil boluses (2.5 μg/kg) were given after repinotan (10 and 20 μg/kg). Results (1) Remifentanil-induced antinociception lasted only 5 min after infusion was stopped (tail-flick reflex latencies; median [interquartile range], 97 [54-100]% of maximum possible effect; P = 0.034), but was extended by repinotan (10 μg/kg) to 30 min (tail-flick reflex latencies, 100 [75-100]% of maximum possible effect; P = 0.031). Repinotan (10 μg/kg) alone did not have any significant antinociceptive effect. (2) The ventilatory depression by remifentanil boluses (2.5 μg/kg; minute ventilation, -65 [-81 to -56]%; P = 0.031, n = 5) was blunted by repinotan (20 μg/kg; minute ventilation, -24 [-53 to 13]%; P = 0.313, compared with the pretreatment level). Conclusions Repinotan prevented remifentanil-induced ventilatory depression in spontaneously breathing, anesthetized rats. Although repinotan did not depress nociception itself, it prolonged the profound antinociception after discontinuation of remifentanil infusion.

Sign in / Sign up

Export Citation Format

Share Document