Anti-nociceptive effect induced by somatostatin released from sensory nerve terminals and by synthetic somatostatin analogues in the rat

• Published in: Neuroscience letters Vol. 278; no. 3; pp. 185 - 188
• Main Authors: Helyes, Zsuzsanna, Thán, Márta, Oroszi, Gábor, Pintér, Erika, Németh, József, Kéri, György, Szolcsányi, János
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 14-01-2000; Elsevier
• Subjects: Analgesics - pharmacology; Animals; Anti-nociceptive effect; Antidromic nerve stimulation; Biological and medical sciences; Blood Pressure - drug effects; Capsaicin - administration & dosage; Capsaicin - pharmacology; Capsaicin-sensitive; Chemonociceptive reflexes; Female; Fundamental and applied biological sciences. Psychology; Heart Rate - drug effects; Mustard oil; Mustard Plant; Nerve Endings - metabolism; Neurons, Afferent - metabolism; Neurons, Afferent - physiology; Nociceptors - physiology; Octreotide; Peptides, Cyclic - pharmacology; Plant Extracts - administration & dosage; Plant Extracts - pharmacology; Plant Oils; Rats; Rats, Wistar; RC-160; Respiration - drug effects; Skin - innervation; Somatostatin - analogs & derivatives; Somatostatin - metabolism; Somatostatin - pharmacology; Somatostatin - physiology; Somesthesis and somesthetic pathways (proprioception, exteroception, nociception); interoception; electrolocation. Sensory receptors; TT-232; Vertebrates: nervous system and sense organs; Antidromic nerve stimulation; Chemonociceptive reflexes; TT-232; Octreotide; Mustard oil; Capsaicin-sensitive; RC-160; Anti-nociceptive effect; Nociception; Rat; Rodentia; Chemoreception; Heart rate; Analgesia; Vertebrata; Nerve ending; Mammalia; Arterial pressure; Somatostatin; Respiration; Sciatic nerve
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/S0304-3940(99)00936-2

In rats anaesthetized with urethan and pretreated with pipecuronium bromide nocifensive reaction of blood pressure elevation evoked by intraarterial capsaicin injection was inhibited over 40 min by bilateral antidromic stimulation of the sensory fibres of the sciatic nerves. Rise in blood pressure, heart rate and respiratory frequency evoked by capsaicin were markedly diminished after smearing 1% mustard oil on the acutely denervated hindpaws indicating a release of mediators with anti-nociceptive action from cutaneous nociceptors. Intravenous injection of the putative mediator somatostatin (10 μg/kg) or its analogues RC-160 and TT-232, but not octreotide inhibited the cardiorespiratory and blood pressure responses evoked by topical cutaneous application of mustard oil or capsaicin instillation into the eye. It is concluded, that the endocrine and the anti-nociceptive effects of somatostatin are mediated through distinct receptor subtypes and therefore, TT-232, a novel heptapeptide analogue without endocrine action, is a promising analgesic compound.