Reduced effects of endothelium-derived hyperpolarizing factor in ocular ciliary arteries from spontaneous hypertensive rats

Experimental Eye Research
Yaru DongTakeshi Yoshitomi

Abstract

Vascular peripheral resistance is increased during hypertension, and endothelium-derived hyperpolarizing factor (EDHF) is an important for regulating vasodilation in small arteries. Therefore we characterized the role of EDHF in regulating vascular resistance of ocular ciliary arteries from spontaneous hypertensive rats (SHR) and age-matched Wistar Kyoto rats (WKY). Isometric tension recordings were used in isolated ocular ciliary artery segments from SHR and WKY. Ocular ciliary arteries pre-contracted with 100 microM norepinephrine exhibited a concentration-dependent relaxation to acetylcholine, and the effect on SHR arteries was smaller than that on WKY arteries (P < 0.05). The EDHF-mediated component of this relaxation, determined in the presence of 100 microM l-NAME plus 10 microM indomethacin, was also smaller in SHR than in WKY arteries (P < 0.05). Apamin (1 microM), a blocker of small-conductance calcium-activated K(+) (K(Ca)) channels, had no effect on EDHF-mediated relaxation in either preparation. However, charybdotoxin (0.1 microM), which blocks intermediate- and large-conductance K(Ca) channels, and iberiotoxin (0.1 microM), which blocks large-conductance K(Ca) channels, almost completely suppressed EDHF-mediated re...Continue Reading

References

Feb 1, 1978·The Journal of Physiology·W HalpernD M Warshaw
Apr 15, 1976·Nature·M J Mulvany, W Halpern
Aug 1, 1985·Circulation Research·D R HarderJ Lombard
Mar 12, 1999·Journal of Molecular and Cellular Cardiology·C M Boulanger
Dec 10, 1999·British Journal of Pharmacology·G EdwardsA H Weston
Mar 22, 2000·British Journal of Pharmacology·J F QuignardP M Vanhoutte
Feb 22, 2002·Current Opinion in Nephrology and Hypertension·William B Campbell, Kathryn M Gauthier
Jun 7, 2006·Hypertension Research : Official Journal of the Japanese Society of Hypertension·Yoshitomo MoriTadaaki Iwasaki
Dec 21, 2006·Japanese Journal of Ophthalmology·Yaru DongTakeshi Yoshitomi
Apr 27, 2007·Experimental Eye Research·Yaru DongTakeshi Yoshitomi
Jul 8, 2008·Experimental Eye Research·Yaru DongTakeshi Yoshitomi

❮ Previous
Next ❯

Citations

Mar 11, 2011·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Harald M StaussMichael G Anderson
Jan 25, 2018·International Journal of Molecular Sciences·Kenichi GotoTakanari Kitazono
Nov 29, 2017·Bulletin of Experimental Biology and Medicine·D V Unt, G I Lobov

❮ Previous
Next ❯

Related Concepts

Related Feeds

Antihypertensive Agents: Mechanisms of Action

Antihypertensive drugs are used to treat hypertension (high blood pressure) which aims to prevent the complications of high blood pressure, such as stroke and myocardial infarction. Discover the latest research on antihypertensive drugs and their mechanism of action here.

Calcium & Bioenergetics

Bioenergetic processes, including cellular respiration and photosynthesis, concern the transformation of energy by cells. Here is the latest research on the role of calcium in bioenergetics.