Cardiac baroreflex is already blunted in eight weeks old spontaneously hypertensive rats

Cisternas, José R; Valenti, Vítor Engrácia; Alves, Thales Biffe; Ferreira, Celso; Petenusso, Marcio; Breda, João Roberto; Pires, Ana Maria; Tassi, N; Abreu, Luíz Carlos de

doi:10.1186/1755-7682-3-2

Cited by 20 publications

(21 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Pulsatile arterial pressure (PAP) of freely moving animals was recorded using an HP-7754A preamplifier (Hewlett Packard, USA) and an acquisition board (MP100A, Biopac Systems Inc, USA) connected to a computer. Mean arterial pressure (MAP) and heart rate (HR) values were derived from the PAP recordings and processed on-line 4,9,10 .…”

Section: Surgical Proceduresmentioning

confidence: 99%

Efeitos da exposição à fumaça lateral do cigarro sobre o barorreflexo em ratos adultos

Valenti¹,

Abreu²,

Ferreira³

2011

Arq. Bras. Cardiol.

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Surgical Proceduresmentioning

confidence: 99%

Efeitos da exposição à fumaça lateral do cigarro sobre o barorreflexo em ratos adultos

Valenti¹,

Abreu²,

Ferreira³

2011

Arq. Bras. Cardiol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In spontaneously hypertensive rats, the baroreflex pathway is considered to be disordered. [20][21][22] In this study, in Wistar rats the baro-excited neurons in the CVLM depolarized pressure dependently. However, we speculate that those neurons may depolarize less pressure dependently in spontaneously hypertensive rats than in Wistar rats.…”

Section: Modified Brainstem-spinal Cord Preparation and Identificatiomentioning

confidence: 66%

Baro-excited neurons in the caudal ventrolateral medulla (CVLM) recorded using the whole-cell patch-clamp technique

et al. 2011

View full text Add to dashboard Cite

Caudal ventrolateral medulla (CVLM) neurons have important roles in the regulation of sympathetic nerve activity and blood pressure through their tonic inhibition of rostral ventrolateral medulla neurons. As few reports have demonstrated CVLM neuronal activity using the whole-cell patch-clamp technique, we attempted to find neurons in the CVLM that are depolarized by the stimulation of baroreceptors. To record the membrane potentials of the neurons in the CVLM, we developed a modified brainstem-spinal cord preparation that enabled us to change the pressure exerted on the aortic arch and carotid sinuses. We were able to identify neurons in the CVLM in which they were depolarized and the action potential (AP) frequency was increased upon baroreceptor stimulation. We referred to these neurons as baro-excited CVLM neurons. When these preparations were superfused with an angiotensin-II (Ang-II) solution, the frequency of the APs increased in 10 of the 14 baro-excited CVLM neurons. Superfusion with a low-Ca 2+ , high-Mg 2+ solution abolished the APs in all seven baro-excited CVLM neurons, suggesting that the baro-excited CVLM neurons did not fire spontaneously. When the preparation was superfused with a low-Ca 2+ solution, 6 of the 7 baro-excited CVLM neurons did not respond to Ang-II superfusion. We for the first time found the baro-excited CVLM neurons, which depolarized pressure dependently but may not fire spontaneously. As Ang-II did not change the activity of the CVLM neurons during superfusion with a low-Ca 2+ , high-Mg 2+ solution, the presynaptic neurons may be mandatory for the Ang-II-induced activation of postsynaptic baro-excited CVLM neurons.

show abstract

“…The changes in diastolic arterial pressure observed in our study associated with epidural clonidine and ketamine administration is most likely explained by two interacting mechanisms. First, systemic uptake of clonidine and ketamine from the epidural space into the systemic circulation will cause secondary interactions with centers in the brain stem (that is, locus coeruleus, rostroventrolateral medulla, nucleus ambiguous and the nucleus of the solitary tract) that affect neural regulation of the cardiovascular system (Valenti et al, 2009a;Valenti et al, 2009b;Cisternas et al, 2010). Second, epidural clonidine and ketamine in the dose used by us is associated with improved postoperative pain relief (De Negri et al, 2001).…”

Section: Discussionmentioning

confidence: 99%

Comparison between S-ketamine and clonidine in caudal analgesia

Ribeiro¹

2011

Afr. J. Pharm. Pharmacol.

View full text Add to dashboard Cite

We aimed to compare the analgesic efficacy of the caudal administration of a combination of preservative free S-ketamine or clonidine with bupivacaine in children. The study included 51 children aged between 3 and 8 years old and physical status between I and II according to: American Society of Anesthesiologist. They were randomly divided into three groups: Group B -bupivacaine 0.25%, 0.75 ml/kg without adrenaline; Group C -bupivacaine 0.25%, 0.75 ml/kg without adrenaline and clonidine 1 µg/kg and; Group K -bupivacaine 0.25%, 0.75 ml/kg without adrenaline and S-ketamine 0.5 mg/kg without conservative. In this study, medication was not used before anesthesia. The evaluation of postoperative analgesia was accomplished through the pain scale of Ouch, the motor blockade assessed by modified Bromage scale and the level of sedation through the three-point scale. The combination of caudal S-ketamine and clonidine with bupivacaine prolonged the duration of postoperative analgesia (p < 0.05) compared to bupivacaine alone. Regarding hemodynamic parameters, bupivacaine associated with clonidine (C) and bupivacaine associated with S-ketamine (K) groups presented diastolic blood pressure changes in the postoperative period. Respiratory rate, regardless of group, showed significant differences over time (p <0.05). The studied groups showed non significant changes in the degree of motor blockade and sedation score and we observed no clinical significant side effects. S-ketamine and clonidine associated with bupivacaine prolongs postoperative analgesia without clinically significant side effects.

show abstract

Cardiac baroreflex is already blunted in eight weeks old spontaneously hypertensive rats

Cited by 20 publications

References 29 publications

Efeitos da exposição à fumaça lateral do cigarro sobre o barorreflexo em ratos adultos

Efeitos da exposição à fumaça lateral do cigarro sobre o barorreflexo em ratos adultos

Baro-excited neurons in the caudal ventrolateral medulla (CVLM) recorded using the whole-cell patch-clamp technique

Comparison between S-ketamine and clonidine in caudal analgesia

Contact Info

Product

Resources

About