Prostaglandin F<sub>2α</sub>가 가토 대동맥 평활근 수축성에 미치는 영향
The Effects of Prostaglandin F<sub>2α</sub> on the Contractility of Vascular Smooth Muscle in the Aortic Strip of Rabbits
- 정수성(Chung, Soo-Sung) 김세훈(Kim, Se-Hoon) 장석종(Chang, Seok-Jong) 박해근(Park, Hae-Kun)
- 대한생리학회
- 대한생리학회지
- 제23권 제1호
- 1989.06
- 99 - 108 (10 pages)
The effects of prostaglandin (PGF<sub>2α</sub>) on the contractility of vascular smooth muscle were investigated in the helical strip of the rabbit aorta. The aortic strip was immersed in the phosphate-buffered Tyrode s solution which was equilibrated with 100% O_{2} at 35℃ and its isometric tension was measured. The contraction was induced by (PGF<sub>2α</sub>), norepinephrine (NE), or potassium (40 mM) in the nomal Tyrode s solution (1 mM, Ca<sup>2+</sup>) or Ca<sup>2+</sup>-free Tyrode s solution. Effects of verapamil and phentolamine on the contraction were also observed. The aortic strip began to contract at the concentration of 5 μg% and reached the maximal contraction at the concentration of 150 μg% (PGF<sub>2α</sub>). The maximal contraction was corresponded respectively to 52.2±3.0% and 81.5±3.5% of maximal contraction by NE (1 X 10<sup>-5</sup>M) and 40 mM K<sup>+</sup>. And the maximal contractions by (PGF<sub>2α</sub>) or NE were induced at the concentration of about 1 mM Ca<sup>2+</sup>. (PGF<sub>2α</sub>) induced the contraction of aortic strip even after induction of contraction by 40 mM K<sup>+</sup> and the contraction by (PGF<sub>2α</sub>) was not blocked by the α-receptor blocker, phentolamine. And the contraction by the (PGF<sub>2α</sub>) was inhibited partially by a verapamil at the concentration of 1 X 10<sup>-5</sup>M and the contraction began to increase at the concentration of 1 X 10<sup>-4</sup>M verapamil. Whereas the contraction by NE was completely blocked by verapamil. Though both the (PGF<sub>2α</sub>) and NE induced the contraction in the Ca<sup>2+</sup>-free Tyrode s solution, the peak tension was not maintained. But the rate of tension decline was lower in the contraction by (PGF<sub>2α</sub>) than in that by NE. The verapamil did not inhibit the contraction by (PGF<sub>2α</sub>) in the Ca<sup>2+</sup>-free Tyrode s solution and increased the contraction at the concentration of above 1 X 10<sup>-4</sup>M. The NE-induced contraction in the Ca<sup>2+</sup>-free Tyrode s solution was inhibited completely by a verapamil. From the above results it is suggested that the contraction induced by (PGF<sub>2α</sub>) results from the promotion of the both Ca<sup>2+</sup> influx and the intracellular Ca<sup>2+</sup> release by different way from NE.