HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 540/1/285    most recent 2001.013188v1 Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Saito, H. Articles by Takewaki, T. Search for Related Content PubMed PubMed Citation Articles by Saito, H. Articles by Takewaki, T.

Reversible impairment of endothelium-dependent relaxation in golden hamster carotid arteries during hibernation

Hideki Saito, Sharada Thapaliya, Hayato Matsuyama, Masakazu Nishimura, Toshihiro Unno, Seiichi Komori and Tadashi Takewaki

The effects of hibernation on endothelium-dependent vasodilatation were investigated in the golden hamster carotid artery, paying special attention to hibernating body temperature (10 °C). To record mechanical and electrical membrane responses, we applied pharmacological (organ bath) and electrophysiological (microelectrode) techniques, using acetylcholine (ACh; 0.001-100 µM) and ATP (0.01-1000 µM) for endothelium-dependent vasodilatation and sodium nitroprusside (SNP; 0.05-10 µM) for endothelium-independent vasodilatation. At 34 °C, ACh, ATP and SNP each induced a relaxation or a hyperpolarization, and these responses were similar in all the preparations from control and hibernated animals. At 10 °C, on the other hand, ACh-induced relaxations and hyperpolarizations were reduced to approximately 35 % and 50 % of the euthermic level in controls and 1 % and 4 % of the euthermic level in hibernated animals, respectively. In contrast, at 10 °C, ATP induced only a contraction or depolarization in all preparations with no significant difference between control and hibernated animals. SNP-induced relaxations and hyperpolarizations obtained at 34 °C were not attenuated by cooling to 10 °C. In the presence of a P2X receptor blocker, pyridoxal phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS; 5 µM), at 34 °C ATP-induced relaxations and hyperpolarizations were significantly enhanced whereas no responses were induced by ATP at 10 °C. After endothelium removal, on the other hand, ATP induced only a contraction or depolarization at both 34 °C and 10 °C. These results suggest that depression of endothelium-dependent vasodilator responses to ACh and ATP may occur in the hibernating golden hamster carotid artery.

This article has been cited by other articles:

				S. Miyazawa, Y. Shimizu, T. Shiina, H. Hirayama, H. Morita, and T. Takewaki Central A1-receptor activation associated with onset of torpor protects the heart against low temperature in the Syrian hamster Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2008; 295(3): R991 - R996. [Abstract] [Full Text] [PDF]

				P. G. Osborne, J. Sato, N. Shuke, and M. Hashimoto Sympathetic {alpha}-adrenergic regulation of blood flow and volume in hamsters arousing from hibernation Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2005; 289(2): R554 - R562. [Abstract] [Full Text] [PDF]