Role of calcitonin gene-related peptide and capsaicin-sensitive afferents in central thyrotropin-releasing hormone-induced hepatic hyperemia

• Published in: European journal of pharmacology Vol. 380; no. 1; pp. 31 - 35
• Main Authors: Tamori, Keisuke, Yoneda, Masashi, Yokohama, Shiro, Sato, Yoichi, Nakamura, Kimihide, Kono, Toru, Makino, Isao, Terano, Akira
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 03.09.1999; Elsevier
• Subjects: Animals; Autonomic nervous system; Biological and medical sciences; Calcitonin Gene-Related Peptide - pharmacology; Calcitonin Gene-Related Peptide - physiology; Capsaicin - pharmacology; Cattle; Fundamental and applied biological sciences. Psychology; Hepatic microcirculation; Humans; Hyperemia - chemically induced; Hyperemia - physiopathology; Injections, Intravenous; Liver - blood supply; Liver. Bile. Biliary tracts; Male; Neurons, Afferent - physiology; Neuropeptide; Peptide Fragments - pharmacology; Peptide Fragments - physiology; Peripheral nervous system. Autonomic nervous system. Neuromuscular transmission. Ganglionic transmission. Electric organ; Rats; Rats, Wistar; Regional Blood Flow - drug effects; Serum Albumin, Bovine - pharmacology; Thyrotropin-Releasing Hormone - pharmacology; Time Factors; Vagus; Vertebrates: digestive system; Vertebrates: nervous system and sense organs; Vagus; Autonomic nervous system; Neuropeptide; Hepatic microcirculation; Rat; Digestive system; Capsaicin; Liver; Peptide hormone; Rodentia; Calcitonine gene related peptide; Biological activity; Blood flow; Microcirculation; Vertebrata; Thyrotropin releasing hormone; Mammalia; Animal; Blood vessel; Sensory neuron; Circulatory system
• ISSN: 0014-2999; 1879-0712
• DOI: 10.1016/S0014-2999(99)00527-0

The involvement of capsaicin-sensitive afferent neurons and calcitonin gene-related peptide (CGRP) in the central thyrotropin-releasing hormone (TRH)-induced hepatic hyperemia was investigated in urethane anesthetized rats. Both systemic capsaicin pretreatment and intravenous administration of CGRP receptor antagonist, human CGRP-(8–37), completely abolished the stimulatory effect of hepatic blood flow induced by intracisternal injection of TRH analog (RX-77368; p-Glu-His-(3,3′-dimethyl)-Pro-NH2, 100 ng), assessed by the hydrogen gas clearance method. These data demonstrate the involvement of capsaicin-sensitive afferent neurons and CGRP in the central TRH-induced stimulation of hepatic blood flow.