1. Modulation Of Arachidonic Acid-Evoked Cardiorespiratory Effects By The Central Lipoxygenase Pathway
- Author
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Leman Gizem Erkan, Gokcen Guvenc-Bayram, Murat Yalcin, and Burcin Altinbas
- Subjects
Pulmonary and Respiratory Medicine ,Physiology ,Partial Pressure ,Lipoxygenase ,Prostaglandin ,Pharmacology ,03 medical and health sciences ,Thromboxane A2 ,chemistry.chemical_compound ,0302 clinical medicine ,Respiratory Rate ,Heart Rate ,Hyperventilation ,Tidal Volume ,medicine ,Animals ,Masoprocol ,Arterial Pressure ,Lipoxygenase Inhibitors ,Respiratory system ,Injections, Intraventricular ,Arachidonic Acid ,biology ,General Neuroscience ,Carbon Dioxide ,Rats ,Oxygen ,Nordihydroguaiaretic acid ,030228 respiratory system ,chemistry ,biology.protein ,Arachidonic acid ,lipids (amino acids, peptides, and proteins) ,Cyclooxygenase ,Blood Gas Analysis ,medicine.symptom ,030217 neurology & neurosurgery ,Respiratory minute volume - Abstract
We previously reported that intracerebroventricularly (ICV) injected arachidonic acid (AA) could produce pressor and bradycardic responses on the cardiovascular system and hyperventilation effect on the respiratory system by activating cyclooxygenase (COX). We also demonstrated that centrally injected AA-induced cardiovascular and respiratory responses were mediated by COX-metabolites, such as thromboxane A2 (TXA2), prostaglandin (PG) D, PGE, and PGF2α. Brain tissue is also able to express the lipoxygenase (LOX) enzyme and LOX-induced AA-metabolites. The current study was designed to investigate the possible mediation of the central LOX pathway in AA-induced cardiorespiratory effects in anesthetized rats. Central pretreatment with different doses of a non-selective LOX inhibitor, nordihydroguaiaretic acid (NDGA) (500 and 1000 μg; ICV) partially blocked the AA (0.5 μmol; ICV)-evoked pressor and bradycardic cardiovascular responses in male anesthetized Sprague Dawley rats. Pretreatment with different doses of NDGA (500 and 1000 μg; ICV) also reduced AA-induced hyperventilation responses, with an increase in tidal volume, respiratory rate and minute ventilation, in the rats. Moreover, AA-induced increasing pO2 and decreasing pCO2 responses were diminished by central NDGA pretreatment. In summary, our findings show that the central LOX pathway might mediate, at least in part, centrally administered AA-evoked cardiorespiratory and blood gases responses.
- Published
- 2020