PMID- 10556932
OWN - NLM
STAT- MEDLINE
DCOM- 20000124
LR  - 20240315
IS  - 0007-1188 (Print)
IS  - 0007-1188 (Linking)
VI  - 128
IP  - 5
DP  - 1999 Nov
TI  - Effects of cyclopiazonic acid on contraction and intracellular Ca2+ in 
      oesophageal striated muscle of normotensive and spontaneously hypertensive rats.
PG  - 961-8
AB  - 1. The effects of cyclopiazonic acid (CPA), a selective inhibitor of sarcoplasmic 
      reticulum (SR) Ca2+-ATPase, on twitch contraction and on the resting state of 
      tension and intracellular Ca2+ level ([Ca2+]i) of the oesophageal striated muscle 
      of stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive Wistar 
      Kyoto rats (WKY) were compared. 2. CPA (10 micronM) augmented the twitch 
      contraction of oesophageal striated muscle preparations from both SHRSP and WKY, 
      reducing the rate of relaxation (-dT/dt), and thus resulting in the prolongation 
      of the time to 80% relaxation. The effect was significantly smaller in the SHRSP 
      preparations. 3. In the resting state, CPA caused a sustained elevation of 
      [Ca2+]i. The elevation was greater in the WKY preparations. Tension development 
      accompanied by the elevation was observed in WKY preparations, but not in SHRSP 
      preparations. 4. The sustained elevation of [Ca2+]i induced by CPA was eliminated 
      by the removal of extracellular Ca2+. Both the elevated [Ca2+]i and tension in 
      the preparations from WKY were reduced by flufenamic acid (100 micronM), 
      mefenamic acid (100 micronM), lanthanum (La3+, 100 micronM), gadolinium (Gd3+, 
      100 micronM) and SK&F 96365 (100 micronM) but not by verapamil (10 micronM). 5. 
      Thapsigargin (3 micronM), another SR Ca2+-ATPase inhibitor, produced similar 
      effects on basal tension to those of CPA, although it reduced the amplitude of 
      twitch contraction. 6. These results suggest that in the rat oesophageal striated 
      muscle, (1) CPA extends the sequestrating time of Ca2+ into the SR, (2) CPA 
      induces a Ca2+ influx mediated through verapamil-insensitive pathways, possibly 
      nonselective cation channels, and (3) the mechanism of [Ca2+](i) modulation due 
      to CPA-sensitive SR Ca2+-ATPase is deteriorated in the oesophageal striated 
      muscle from SHRSP as compared with WKY preparations.
FAU - Sekiguchi, F
AU  - Sekiguchi F
AD  - Faculty of Pharmaceutical Sciences, Kinki University, 3-4-1 Kowakae, 
      Higashi-osaka, Osaka 577-8502, Japan.
FAU - Shimamura, K
AU  - Shimamura K
FAU - Kawata, K
AU  - Kawata K
FAU - Nakazawa, Y
AU  - Nakazawa Y
FAU - Saitoh, R
AU  - Saitoh R
FAU - Yanagitani, Y
AU  - Yanagitani Y
FAU - Sunano, S
AU  - Sunano S
LA  - eng
PT  - Journal Article
PL  - England
TA  - Br J Pharmacol
JT  - British journal of pharmacology
JID - 7502536
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Indoles)
RN  - 0 (Ion Channels)
RN  - 67526-95-8 (Thapsigargin)
RN  - EC 7.2.2.10 (Calcium-Transporting ATPases)
RN  - SY7Q814VUP (Calcium)
RN  - X9TLY4580Z (cyclopiazonic acid)
SB  - IM
MH  - Animals
MH  - Blood Pressure/drug effects
MH  - Body Weight/drug effects
MH  - Calcium/*metabolism
MH  - Calcium-Transporting ATPases/*antagonists & inhibitors
MH  - Enzyme Inhibitors/*pharmacology
MH  - Esophagus/drug effects/*metabolism
MH  - Hypertension/genetics/*metabolism
MH  - In Vitro Techniques
MH  - Indoles/*pharmacology
MH  - Ion Channels/drug effects
MH  - Male
MH  - Muscle Contraction/drug effects
MH  - Muscle, Smooth/*drug effects/metabolism
MH  - Rats
MH  - Rats, Inbred SHR
MH  - Rats, Inbred WKY
MH  - Sarcoplasmic Reticulum/drug effects/enzymology
MH  - Thapsigargin/pharmacology
PMC - PMC1571716
EDAT- 1999/11/11 00:00
MHDA- 1999/11/11 00:01
PMCR- 2000/11/01
CRDT- 1999/11/11 00:00
PHST- 1999/11/11 00:00 [pubmed]
PHST- 1999/11/11 00:01 [medline]
PHST- 1999/11/11 00:00 [entrez]
PHST- 2000/11/01 00:00 [pmc-release]
AID - 0702867 [pii]
AID - 10.1038/sj.bjp.0702867 [doi]
PST - ppublish
SO  - Br J Pharmacol. 1999 Nov;128(5):961-8. doi: 10.1038/sj.bjp.0702867.