Potential greater than additive vasorelaxant actions of milrinone and nitroglycerin on human conduit arteries

Abstract

1 The mechanism of vasorelaxation for phosphodiesterase I11 inhibitors is mediated by increase of cAMP whereas for nitrovasodilators, cGMP. Pretreatment with the combination depressed contraction to a higher extend compared with milrinone alone (P < 0.05) for the K+-induced contraction and to NTG alone ( P < 0.05) in U46619-induced contraction. Treatment with the combination also shifted ECS0 rightward and this shift was significantly more than that caused by treatment with NTG alone (P<O.O5). 4 We conclude that there is a greater than additive vasorelaxant effect of PDE I11 inhibitors and nitrovasodilators in human conduit arteries. This effect may be beneficial to patients undergoing coronary artery bypass grafting and to other patients requiring these vasodilators. Reduced doses of the vasodilators in concentration may be sufficient to produce vasodilatation similar to that produced by either of them alone at higher concentrations.

Inhibition of lung phosphodiesterase improves responsiveness to inhaled nitric oxide in isolated-perfused lungs from rats challenged with endotoxin

“…In patients with pulmonary hypertension associated with congestive heart failure, a single intravenous bolus of milrinone decreased both PAP and pulmonary vascular resistance [17]. He et al [18] reported that in human conduit arteries precontracted with either U46619 or potassium the combined treatment with milrinone and nitroglycerin resulted in greater relaxation than that with milrinone alone [18]. In our study, the addition of milrinone did not further vasodilate lungs obtained from LPS-treated rats ventilated with NO (Fig.…”

The Effect of Milrinone on the Right Ventriclular Function in Patients with Reduced Right Ventricular Function Undergoing Off-pump Coronary Artery Bypass Graft Surgery

“…This, as well as the increased CO in the milrinone group, is presumed to be the result of the uncompensated vasodilatory effect of milrinone. Preload reduction would also be complicated with administration of nitrate agents with additive vasorelaxation effect (16). Given normal or near-normal RV afterload, preload is the determinant for the RV performance (17).…”

Pharmacology of Arterial Grafts for Coronary Artery Bypass Surgery

“…These drugs are useful in postoperative management of patients who undergo open heart surgery, particularly in patients who present ventricular dysfunction and receive arterial grafts for coronary artery bypass surgery. Favorable effects of inamrinone on the IMA [76,[86][87][88] have been reported. In addition, it has been demonstrated that inamrinone has a greater than additive vasodilatory effect when used in combination with NTG [76].…”

“…Favorable effects of inamrinone on the IMA [76,[86][87][88] have been reported. In addition, it has been demonstrated that inamrinone has a greater than additive vasodilatory effect when used in combination with NTG [76]. It was also demonstrated that systemically administered milrinone and nitroglycerin dilate the IMA after cardiopulmonary bypass [82].…”

“…These drugs are effective against a range of constrictor stimuli and they are widely used in CABG patients. Nitrovasodilators have been shown to be potent vasodilators in the human IMA [55,61,[74][75][76][77][78][79]. It has been demonstrated that NTG is compares favorably with diltiazem in the prevention of IMA spasm [80] and it is effective for either topical, intraluminal, or systemic use [78,81,82].…”