기관회원 [로그인]
소속기관에서 받은 아이디, 비밀번호를 입력해 주세요.
개인회원 [로그인]

비회원 구매시 입력하신 핸드폰번호를 입력해 주세요.
본인 인증 후 구매내역을 확인하실 수 있습니다.

회원가입
서지반출
Inositol 1,4,5-Trisphosphate-induced Increase in Ca2+-ATPase Activity in the Microsomes of Tracheal Epithelial Cells
[STEP1]서지반출 형식 선택
파일형식
@
서지도구
SNS
기타
[STEP2]서지반출 정보 선택
  • 제목
  • URL
돌아가기
확인
취소
  • Inositol 1,4,5-Trisphosphate-induced Increase in Ca2+-ATPase Activity in the Microsomes of Tracheal Epithelial Cells
저자명
Cho, Hyoung-Jin,Park, Sung-Shin,Kim, Young-Kee
간행물명
대한생리학회지
권/호정보
1995년|29권 2호(통권56호)|pp.269-278 (10 pages)
발행정보
대한생리학회|한국
파일정보
정기간행물|ENG|
PDF텍스트(0.22MB)
주제분야
의약학
서지반출

영문초록

Membrane vesicles were prepared by differential centrifugation from epithelial cells of porcine trachea. Total activity of microsomal ATPases was measured spectrophotometrically by a coupled enzyme assay. The steady-state activity of the enzyme was 329±10 nmol/min mg protein. Thapsigargin, a specific antagonist of intracellular Ca2+-ATPase, inhibited about 50% of the activity, leaving 178±18 nmol/min .mg protein (n=6), indicating that the Ca2+-ATPase is one of the major microsomal ATPases. The microsomes used in this study appeared to be tight-sealed vesicles since they showed saturation in 45Ca2+ uptake experiments. Inositol 1,4,5-trisphosphate InsP3, 4 μM, an agonist of InsP_{3}-sensitive Ca2+ release channel (InsP3, receptor), and Ca-ionophore A23187 (10 μM) induced 45Ca2+ releases of 20% and 50% of stored 45Ca2+, respectively. The addition of (10 μM InsP3 also increased the microsomal ATPase activity from 282±8 nmol/min mg protein to 334±21 nmol/min . mg protein in the intact vesicles. Similar increase in the activity was observed by making microsomes leaky (uncoupling) using the Ca-ionophore A23187. ;InsP3-induced effects were blocked by either thapsigargin or heparin suggesting that: 1) the InsP3-induced increase in ATPase activity is mediated by microsomal Ca2+-ATPase, and 2) dissipation of Ca2+ gradient across the microsomal membrane is responsible for the InsP3-induced effect. In order to test the dependence of the Ca2+-ATPase activity on the activity of InsP3-induced the activity of ATPases was monitored in various concentrations of free Ca2+ using EGTA-Ca2+ buffers. The Ca2+-dependent biphasic change is the well-known character of InsP3 receptor but not of microsomal Ca2+-ATPase in non-excitable cells; however, the activity of microsomal ATPase appeared biphasic and a maxim진 activity of 397±36nmol/min .mg protein was obtained in the solution containing 100 nM free Ca2+. Below or above this concentration, the activity of ATPases was lower. These results strongly support a positive correlation of microsomal Ca2+-ATPase to the InsP3 receptors in epithelial microsomes.

구매하기 (3,000)