Morphine-induced modulation of sciatic nerve stimulation evoked blood pressure responses.
Effect of i.v. morphine (1-2 mg/kg) on blood pressure changes evoked by sciatic nerve stimulation (SNS) were studied in chloralose anaesthetised cats. SNS gave a depressor, pressor or a biphasic BP response generally linked to the parameters of stimulation. Morphine produced marked attenuation of depressor and some facilitation of pressor response, suggesting a possible reciprocal relationship between depressor and pressor responses. Depressor response has been correlated with deep tissue or visceral pain mediated through A delta fibres and pressor response to cutaneous nociception involving C fibres or non nociceptive input via group II fibres. Involvement of medullary regions in differential modulation of these depressor and pressor response has been suggested.
Bhattacharya
N
N
Department of Physiology, University College of Medical Sciences, Shahdara, Delhi.
Mahajan
S
S
Sharma
K N
KN
D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D002415:Cats; D009020:Morphine / Q000494:pharmacology*; D009619:Nociceptors / Q000187:drug effects; D012584:Sciatic Nerve / Q000187:drug effects* / Q000502:physiology
D009020:Morphine