Phosphatidylinositol Responses Are Involved in the Vascular Effects of Thiamylal and Fentanyl

Effects of vasopressors on contractile and phosphatidylinositol responses of rat trachea

“…In vascular smooth muscle, α 1 -adrenoceptor agonists stimulate contraction by activating of the PI response. NE stimulates both contraction and IP 1 accumulation in the rat aorta [6]. To stimulate the contractile response, mobilization of Ca 2ϩ from the sarcoplasmic reticulum by IP 3 and influx of Ca 2ϩ from the extracellular space are indispensable conditions.…”

“…Thus, in the presence of Li ϩ , the accumulation rate of IP 1 reflects the extent of PI response. We measured [ 3 H]IP 1 in tracheal slices incubated with [ 3 H]myo-inositol (Amersham, Tokyo, Japan) [5,6]. The trachea was cut longitudinally and chopped into 1-mm-wide pieces with a McIlwain tissue chopper.…”

Influence of opioids on the vascular tone of isolated porcine coronary artery segments

“…It was demonstrated that fentanyl attenuates norepinephrine‐ (15) and phenylephrine‐mediated contractions (16, 17), and that this effect is independent of endothelial function and of opioid receptors (18). It seems to be mediated by an attenuation of the norepinephrine‐induced phosphatidylinositol response (19).…”

Effects of General Anesthetics on Regulation of the Peripheral Vasculature

“…Theoretically, such decreases or increases in [Ca2+]i would account for the direct vasodilator and vasoconstrictor actions of the narcotic and the barbiturate respectively. 168 Finally, even though the alteration of mechanisms that regulate Ca2+ influx has been the most studied effect of anesthetics at the VSM level, an anesthetic-induced change in Ca2+ sensitivity of the contractile proteins is another potential mechanism by which anesthetics can attenuate VSM tone. Clearly, most current evidence related to the intracellular VSM effects of anesthetics suggests that an attenuation of [Ca2+]i is the predominant mechanism by which these agents reduce VSM tone.…”