These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Impaired coronary contraction to phenylephrine after cardioplegic arrest in diabetic patients.
    Author: Sellke N, Gordon C, Lawandy I, Gorvitovskaia AY, Scrimgeour LA, Fingleton JG, Sellke FW, Feng J.
    Journal: J Surg Res; 2018 Oct; 230():80-86. PubMed ID: 30100044.
    Abstract:
    BACKGROUND: We have previously found that hyperkalemic cardioplegic arrest in the setting of cardiopulmonary bypass (CP/CPB) is associated with impairment of the coronary arteriolar response to phenylephrine in nondiabetic (ND) patients. We hypothesized that diabetes may alter coronary arteriolar response to alpha-1 adrenergic agonist in the setting of CP/CPB. In this study, we further investigated the effects of diabetes on the altered coronary arteriolar response to phenylephrine in patients undergoing cardiac surgery. METHODS: Coronary arterioles (90-150 μm in diameter) were harvested pre- and post-CP/CPB from the ND and diabetic mellitus (DM) patients (n = 8/group) undergoing cardiac surgery. In-vitro microvascular reactivity was examined in response to phenylephrine. The protein expression/localization of the alpha-1 adrenergic receptors in the atrial myocardium was measured by Western blotting and immunohistochemistry. RESULTS: Phenylephrine (10-9 to 10-4 M) induced a dose-dependent contractile response in both ND and DM vessels pre- and post-CP/CPB. There was no significant difference in the pre-CP/CPB contractile responses to phenylephrine between ND and DM groups. The post-CP/CPB contractile response was significantly diminished in both ND and DM groups compared with the respective pre-CP/CPB response (P < 0.05 versus pre-CP/CPB). This diminished contractile response was more pronounced in vessels from DM patients compared with vessels from ND patients (P < 0.05 versus ND). There were no significant differences in the protein expression of alpha-1A and alpha-1B receptors in the atrial myocardium between the ND and DM groups or tissue harvested pre- or post-CP/CPB. CONCLUSIONS: Diabetes is associated with a decreased contractile response of coronary arterioles to phenylephrine in the setting of CP/CPB versus that observed in ND patients. This alteration may contribute to the vasomotor dysfunction of coronary microcirculation seen early after CP/CPB in patients with diabetes.
    [Abstract] [Full Text] [Related] [New Search]