TY - JOUR
T1 - The role of nitrinergic connections in central cardiovascular responses mediated by physostigmine infused into posterior hypothalamus
AU - Palma, Ernesto
AU - Muscoli, Carolina
AU - Mancuso, Eliana
AU - Sculco, Francesca
AU - Sacco, Iolanda
AU - Alecce, Wanessa
AU - Costa, Nicola
AU - Colica, Carmela
AU - Cristiano, Dario
AU - Rotiroti, Domenicantonio
AU - Mollace, Vincenzo
PY - 2004/9/16
Y1 - 2004/9/16
N2 - In the last few decades, cholinergic connections located into posterior hypothalamus (PH) have been implicated in the central regulation of blood pressure (BP). Here we investigated the role of nitric oxide (NO) in the blood pressure response elicited by infusion of physostigmine into PH of normotensive rats. In freely moving rats, physostigmine (60-200 nM) produced a dose- and time-dependent elevation of BP which was antagonized by the antimuscarinic drug scopolamine (60 nM) and by l-NAME (100 μM), an inhibitor of NO synthase, both infused into the same site. In contrast, l-arginine (l-Arg; 100 μM), the precursor of NO, and glyceryltrinitrate (GTN; 140 nM), an NO donor, infused into the PH did not affect physostigmine-related pressor response. In rats pre-treated with Escherichia coli lipopolisaccharide (LPS; 0.5 μg i.p. 24 h beforehand), however, scopolamine, l-Arg and GTN produced a decrease of BP, an effect antagonized by l-NAME. This suggests that NO only slightly modulates physostigmine-related pressor response elicited into PH of LPS-untreated rats. In contrast, the release of large amounts of NO generated by pre-treating rats with LPS, down-regulates cholinergic connections located at the PH, thus contributing in the central dysregulation of BP which can be found when high circulating endotoxin levels may occur.
AB - In the last few decades, cholinergic connections located into posterior hypothalamus (PH) have been implicated in the central regulation of blood pressure (BP). Here we investigated the role of nitric oxide (NO) in the blood pressure response elicited by infusion of physostigmine into PH of normotensive rats. In freely moving rats, physostigmine (60-200 nM) produced a dose- and time-dependent elevation of BP which was antagonized by the antimuscarinic drug scopolamine (60 nM) and by l-NAME (100 μM), an inhibitor of NO synthase, both infused into the same site. In contrast, l-arginine (l-Arg; 100 μM), the precursor of NO, and glyceryltrinitrate (GTN; 140 nM), an NO donor, infused into the PH did not affect physostigmine-related pressor response. In rats pre-treated with Escherichia coli lipopolisaccharide (LPS; 0.5 μg i.p. 24 h beforehand), however, scopolamine, l-Arg and GTN produced a decrease of BP, an effect antagonized by l-NAME. This suggests that NO only slightly modulates physostigmine-related pressor response elicited into PH of LPS-untreated rats. In contrast, the release of large amounts of NO generated by pre-treating rats with LPS, down-regulates cholinergic connections located at the PH, thus contributing in the central dysregulation of BP which can be found when high circulating endotoxin levels may occur.
KW - Blood pressure
KW - Cholinergic system
KW - Nitric oxide
KW - Posterior hypothalamus
UR - http://www.scopus.com/inward/record.url?scp=4444261801&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=4444261801&partnerID=8YFLogxK
U2 - 10.1016/j.neulet.2004.06.075
DO - 10.1016/j.neulet.2004.06.075
M3 - Article
C2 - 15342145
AN - SCOPUS:4444261801
VL - 368
SP - 112
EP - 115
JO - Neuroscience Letters
JF - Neuroscience Letters
SN - 0304-3940
IS - 1
ER -