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Biomedical subjects

Hans Henrik Kimose

Publications and source records attributed to Hans Henrik Kimose.

3 recordsLinked to original sources

Suppressed phospholamban levels differentiate irreversibly dysfunctional from hibernating myocardium in humans.

OBJECTIVES: We studied whether dysfunction of human hibernating (HIB) and irreversibly dysfunctional myocardium (IRDM) are associated with altered levels of the sarcoplasmatic reticulum calcium handling proteins Ca2+-ATPase (SERCA2a) and its inhibitor phospholamban (PLB). DESIGN: In 12 patients myocardial biopsies were taken during bypass surgery and analysed for contents of these proteins. We classified regions as control, HIB, or IRDM based on echocardiographic studies before and 6 months after surgery. RESULTS: SERCA2a content (mean+/-SEM) was similar to control in HIB and IRDM (2.6 +/- 1.7, 3.8 +/- 2.0, and 3.4 +/- 1.9 units/g non-collagen protein (NCP), p = 0.40). PLB content was similar to control in HIB (2.6 +/- 0.4 and 3.5 +/- 0.5 units/microg NCP) but reduced in IRDM (0.9 +/- 0.2 units/microg NCP, p < 0.05). SERCA2a:PLB ratio, an indicator of SERCA2a activity, did not differ between control and HIB (1.2 +/- 0.3 and 1.4 +/- 0.4 units/microg NCP) but was increased in IRDM (5.1 +/- 1.7 units/microg NCP, p < 0.05). CONCLUSIONS: Inappropriate SERCA2a activity due to suppressed PLB levels may represent a maladaptive mechanism in chronic ischemic myocardium being causally linked to irreversibility of left ventricular dysfunction.

Analysis of Variance↗

Angiotensin II inhibition increases cellular glucose transport during reperfusion but not ischemia in pig hearts.

OBJECTIVE: To study whether ACE inhibition and AT-II receptor blockade modulates myocardial glucose uptake during ischemia and reperfusion. DESIGN: We developed a method for in vivo sampling of large trans-myocardial tissue samples from beating pig hearts and in vitro measurement of sarcolemmal glucose transport, in a series of experiments in which hearts were exposed to stimuli (glucose-insulin and pacing) known to promote cellular glucose transport. In the subsequent study we compared three experimental groups: (i) ACE inhibition (ACE-I, n = 6): increasing oral doses of benazepril up to 40 mg daily for 3 weeks, (ii) angiotensin II receptor antagonist (AT II-A, n = 7): increasing oral doses of valsartan up to 320 mg for 3 weeks, (iii) control (n = 7). Samples were harvested at baseline, following 20 min of regional ischemia, and following 5 and 15 min of reperfusion. The samples were incubated with 3-O-methylglucose (MeGlu), and cellular MeGlu uptake was measured. RESULTS: Insulin-glucose, pacing, and ischemia increased cellular MeGlu transport two- to fourfold (p < 0.001). Cellular MeGlu transport was increased in ACE-I and AT II-A animals during reperfusion (p < 0.001), but not at baseline or during ischemia, compared with controls. CONCLUSION: Enhanced capacity for glucose transport during reperfusion may be a mechanism underlying the beneficial effects of ACE inhibition and AT II-antagonism in ischemic heart disease.

Adenosine Triphosphate↗