Effects of prostaglandins on the cytosolic free calcium concentration in vascular smooth muscle cells.
The effects of prostaglandin (PG) F2 alpha and 9,11-epithio-11,12-methanothromboxane A2 (STA2), a stable analogue of thromboxane A2, on the cytosolic free calcium concentration ([Ca2+]i) in vascular smooth muscle cells were studied with a new fluorescent Ca2+ indicator fura 2. PGF2 alpha and STA2, which are strong vasoconstrictors, caused rapid phasic and subsequent tonic increases in [Ca2+]i. PGF2 alpha caused dose-dependent elevation of [Ca2+]i not only in control solution but also in the calcium-free solution. A first stimulation with PGF2 alpha caused dose-dependent decrease in the response of [Ca2+]i to a second stimulation with PGF2 alpha. Pretreatment with 13-Azaprostanoic acid, a receptor level antagonist of thromboxane A2 inhibited the increase of [Ca2+]i induced by STA2. These results suggest that PGF2 alpha induces calcium mobilization followed by smooth muscle contraction through its specific receptors.
Fukuo
K
K
Morimoto
S
S
Koh
E
E
Yukawa
S
S
Tsuchiya
H
H
Imanaka
S
S
Yamamoto
H
H
Onishi
T
T
Kumahara
Y
Y
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001572:Benzofurans; D002118:Calcium / Q000378:metabolism*; D015237:Dinoprost; D005260:Female; D016257:Fura-2; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D011453:Prostaglandins / Q000494:pharmacology*; D011460:Prostaglandins F / Q000494:pharmacology; D011466:Prostanoic Acids / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013928:Thromboxane A2 / Q000031:analogs & derivatives / Q000494:pharmacology; D013997:Time Factors
D001572:Benzofurans; D011453:Prostaglandins; D011460:Prostaglandins F; D011466:Prostanoic Acids; D000804:Angiotensin II; D013928:Thromboxane A2; C022574:13-azaprostanoic acid; C037866:STA 2; D015237:Dinoprost; D002118:Calcium; D016257:Fura-2