title: Emodin accentuates atrial natriuretic peptide secretion in cardiac atria.
abstract: Emodin, an active anthraquinone constituent isolated from the rhubarb, a traditional Chinese herbal medicine which is widely used in clinical treatment, has cardiovascular protective properties. However, it remains unclear whether the cardiovascular protective actions of emodin are related to an activation of cardiac natriuretic hormone secretion. The purpose of the present study was to explore the effect of emodin on the secretion of ANP, a member of the family of cardiac natriuretic hormones, and its mechanisms involved. Experiments were performed in isolated perfused beating rabbit atria allowing measurement of ANP secretion, atrial pulse pressure, and stroke volume. Emodin increased ANP secretion concomitantly with a decrease in atrial pulse pressure and stroke volume in a concentration-dependent manner. These effects were reversible. Inhibition of K(+) channels with tetraethylammonium and glibenclamide attenuated the emodin-induced changes in ANP secretion and atrial dynamics. Furthermore, the emodin-induced changes in ANP secretion and atrial dynamics were attenuated by inhibition of L-type Ca(2+) channels with nifedipine. Atropine, methoctramine, tertiapin-Q, and pertussis toxin had no significant effect on the emodin-induced changes in ANP secretion and mechanical dynamics. The present study demonstrates that emodin increases ANP secretion via inhibition of L-type Ca(2+) channels through an activation of K(+)ATP channel in isolated beating rabbit atria. The results also provide a rationale for the use of emodin in the treatment of impairment of the regulation of the cardiovascular homeostasis.
authors.affiliation: Institute of Atherosclerosis, Key Laboratory of Atherosclerosis in Universities of Shandong, Taishan Medical University, 2 East Yingsheng Road, Taian 271000, Shandong, China.
authors.forename: Guang Hai
authors.initials: GH
authors.lastname: Zhou
authors.affiliation: Institute of Atherosclerosis, Key Laboratory of Atherosclerosis in Universities of Shandong, Taishan Medical University, 2 East Yingsheng Road, Taian 271000, Shandong, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Institute of Atherosclerosis, Key Laboratory of Atherosclerosis in Universities of Shandong, Taishan Medical University, 2 East Yingsheng Road, Taian 271000, Shandong, China.
authors.forename: Xin Nong
authors.initials: XN
authors.lastname: Wang
authors.affiliation: Professional Graduate School of Oriental Medicine, Wonkwang University, Iksan 570-749, Jeonbuk, Republic of Korea.
authors.forename: Oh Jeong
authors.initials: OJ
authors.lastname: Kwon
authors.affiliation: Professional Graduate School of Oriental Medicine, Wonkwang University, Iksan 570-749, Jeonbuk, Republic of Korea.
authors.forename: Dae Gill
authors.initials: DG
authors.lastname: Kang
authors.affiliation: Professional Graduate School of Oriental Medicine, Wonkwang University, Iksan 570-749, Jeonbuk, Republic of Korea.
authors.forename: Ho Sub
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Institute of Materia Medica, Taishan Medical University, Middle of Changcheng Road, Taian 271016, Shandong, China. Electronic address: snjin0504@aliyun.com.
authors.forename: Song Nan
authors.initials: SN
authors.lastname: Jin
authors.affiliation: Institute of Atherosclerosis, Key Laboratory of Atherosclerosis in Universities of Shandong, Taishan Medical University, 2 East Yingsheng Road, Taian 271000, Shandong, China.
authors.forename: Kyung Woo
authors.initials: KW
authors.lastname: Cho
authors.affiliation: Institute of Atherosclerosis, Key Laboratory of Atherosclerosis in Universities of Shandong, Taishan Medical University, 2 East Yingsheng Road, Taian 271000, Shandong, China. Electronic address: jfwen0603@aliyun.com.
authors.forename: Jin Fu
authors.initials: JF
authors.lastname: Wen
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D020746:Calcium Channels, L-Type / Q000502:physiology; D002316:Cardiotonic Agents / Q000494:pharmacology*; D004642:Emodin / Q000494:pharmacology*; D006325:Heart Atria / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D015221:Potassium Channels / Q000502:physiology*; D011817:Rabbits; D011976:Receptors, Muscarinic / Q000502:physiology
chemical_list: D020746:Calcium Channels, L-Type; D002316:Cardiotonic Agents; D015221:Potassium Channels; D011976:Receptors, Muscarinic; D009320:Atrial Natriuretic Factor; D004642:Emodin
keywords: Atrial natriuretic peptide secretion; Cardiac natriuretic hormone; Emodin; K(+)(ATP) channel; L-type Ca(2+) channel