Naslov
Serotonin but not GABA receptors are included in reversal of morphine induced depression of phrenic nerve activity in rats

Autori
Valić, Maja ; Pecotić, Renata ; Eterović, Marija ; Đogaš, Zoran

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Neurologia Croatica / Petravić, D - Zagreb, 2007, 57-57

Skup
Drugi hrvatski kongres neuroznanosti

Mjesto i datum
Zagreb, Hrvatska, 18.03.2007. - 19.03.2007

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
Phrenic nerve recordings; Serotonin; Respiration; Rats
(phrenic nerve recordings; serotonin; respiration; rats)

Sažetak
Introduction: Apart from the classic excitatory (glutamate) and inhibitory (GABA, glycine) neurotransmitters, numerous neuroactive agents have been shown to modulate respiratory activity. Opioids decrease respiration by both central and peripheral actions. Many studies have implicated that serotonin has diverse effects on respiration and may be important in metabolic states such as hypoxia or ischemia. GABA transmits synaptic inhibition in the respiratory network acting primarily on GABAA receptors. The purpose of this study was to determine effects of morphine overdose on phrenic nerve activity and to determine whether serotonin agonist 8-OH-DPAT and GABAA antagonist (bicuculline) may reverse morphine induced respiratory depression. Materials and Methods: Experiments were performed on urethane anaesthetized, spontaneously breathing, vagotomized adult male Sprague Dawley rats weighting 300-330 g. Tracheotomy was performed and trachea cannulated for artificial ventilation when necessary. Femoral artery and vein were cannulated for blood pressure monitoring and drug administration: morphine (15 mg/kg), 5-HT1A receptor agonist 8-OH-DPAT (100 mg/kg) and GABAA receptors antagonist bicuculline (0.33 mg/kg). Morphine was administered until complete depression of phrenic nerve activity (apnea) was induced, and animals were placed on the ventilator. Bicuculline or 8-OH-DPAT were administered intravenously when stabile apnea was produced. Results: Intravenous administration of morphine produced respiratory depression that revealed in gradual decrease of amplitude of the phrenic nerve activity and prolonged duration of inspiratory time, expiratory time and total duration of respiratory cycle. Apnea occurred within 10-12 minutes after the first dose of morphine. Intravenous administration of 5-HT1A receptors agonist 8-OH-DPAT reversed morphine induced phrenic apnea, whereas bicuculline administration failed to reverse morphine induced phrenic apnea. Conclusion: These results suggest that 5-HT1A receptors agonist 8-OH-DPAT, but not GABAA receptors antagonist bicuculline, antagonizes the phrenic apnea produced by morphine overdose.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA