Ca2⁢-induced Ca2⁢ Release from Sarcoplasmic Reticulum Negatively Regulates Myocytic ANP Release in Beating Rabbit Atria

• 영문명: Ca^2⁢-induced Ca^2⁢ Release from Sarcoplasmic Reticulum Negatively Regulates Myocytic ANP Release in Beating Rabbit Atria
• 발행기관: 대한생리학회-대한약리학회
• 저자명: Dan Li He Xiu Quan Jin Fu Wen Jing Yu Jin Sung Hun Park Sun Young Kim Sung Zoo Kim Kyung Woo Cho
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제9권 제2호, 87~94쪽, 전체 8쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 2005.01.01

영문 초록

It is not clear whether Ca^2⁢-induced Ca^2⁢ release from the sarcoplasmic reticulum (SR) is involved in the regulation of atrial natriuretic peptide (ANP) release. Previously, we have shown that nifedipine increased ANP release, indicating that Ca^2⁢ entry via voltage-gated L-type Ca^2⁢ channel activation decreases ANP release. The purpose of the present study was two-fold: to define the role of SR Ca^2⁢ release in the regulation of ANP release and whether Ca^2⁢ entry via L-type Ca^2⁢ channel is prerequisite for the SR-related effect on ANP release. Experiments were performed in perfused beating rabbit atria. Ryanodine, an inhibitor of SR Ca^2⁢ release, increased atrial myocytic ANP release (8.69⁑3.05, 19.55⁑1.09, 27.31⁑3.51, and 18.91⁑4.76% for 1, 2, 3, and 6μM ryanodine, respectively; all P＜0.01) with concomitant decrease in atrial stroke volume and pulse pressure in a dose-dependent manner. In the presence of thapsigargin, an inhibitor of SR Ca^2⁢ pump, ryanodine-induced increase in ANP release was not observed. Thapsigargin attenuated ryanodine-induced decrease in atrial dynamic changes. Blockade of L-type Ca^2⁢ channel with nifedipine abolished ryanodine-induced increase in ANP release (0.69⁑5.58% vs. 27.31⁑3.51%; P＜0.001). In the presence of thapsigargin and ryanodine, nifedipine increased ANP release and decreased atrial dynamics. These data suggest that Ca^2⁢-induced Ca^2⁢ release from the SR is inversely involved in the regulation of atrial myocytic ANP release.

키워드

Atrial natriuretic peptide L-type Ca^2⁢ channels Sarcoplasmic reticulum Ca^2⁢ release