Effects of three types of bariatric interventions on myocardial infarct size and vascular function in rats with type 2 diabetes mellitus.

AIMS: The effects of three types of bariatric interventions on myocardial infarct size were tested in the rat model of type 2 diabetes mellitus (T2DM). We also evaluated the effects of bariatric surgery on no-reflow phenomenon and vascular dysfunction caused by T2DM. MAIN METHODS: Rats with T2DM were assigned into groups: without surgery, sham-operated, ileal transposition, Roux-en-Y gastric bypass, and sleeve gastrectomy. Oral glucose tolerance, glucagon-like peptide-1, and insulin levels were measured. Six weeks after surgery, the animals were subjected to myocardial ischemia-reperfusion followed by histochemical determination of infarct size (IS), no-reflow zone, and blood stasis area size. Vascular dysfunction was characterized using wire myography. KEY FINDINGS: All bariatric surgery types caused significant reductions in animal body weight and resulted in T2DM compensation. All bariatric interventions partially normalized glucagon-like peptide-1 responses attenuated by T2DM. IS was significantly smaller in animals with T2DM. Bariatric surgery provided no additional IS limitation compared with T2DM alone. Bariatric surgeries reversed T2DM-induced enhanced contractile responses of the mesenteric artery to 5-hydroxytryptamine. Sleeve gastrectomy normalized decreased nitric oxide synthase contribution to the endothelium-dependent vasodilatation in T2DM. SIGNIFICANCE: T2DM resulted in a reduction of infarct size and no-reflow zone size. Bariatric surgery provided no additional infarct-limiting effect, but it normalized T2DM-induced augmented vascular contractility and reversed decreased contribution of nitric oxide to endothelium-dependent vasodilatation typical of T2DM. All taken together, we suggest that this type of surgery may have a beneficial effect on T2DM-induced cardiovascular diseases.

Albumin covering maintains endothelial function upon magnetic iron oxide nanoparticles intravenous injection in rats.

Magnetic iron oxide nanoparticles (IONP) present the promising instrument for broad-spectrum of clinical applications, for example, targeted drug delivery. Reactivity of nanoparticles depends on their surface area and material. In the blood plasma IONP are getting covered with an albumin crown, so it was decided to test this shell for biocompatibility. Male Wistar rats were anesthetized and underwent laparotomy. Abdominal aorta was connected to external hemodynamic loop with regulated blood flow. Hind body quarter got step-like blood flow changing from 30 to 150 mmHg and back. This was followed with i.v. injection of IONP, albumin solution or albumin-covered IONP and consequent similar flow changes. Central hemodynamics-heart rate and mean arterial pressure were registered throughout the experiment and no significant changes in these parameters were observed. Hind paw microcirculation level had the same dynamic in all groups under changing blood flow conditions. At the end, venous blood was collected for endothelin-1 and NO evaluation that showed similar changes and no endothelial damage. Mesenteric arteries and femoral artery reactivity were evaluated with wire myography. Mesenteric arteries had the most relaxing function preservation after albumin-covered IONP injection. Given data reveal advantage of albumin-coated IONP so this can be used for further investigations as a vascular-safe vehicle.

Nicotinamide riboside has protective effects in a rat model of mesenteric ischaemia-reperfusion.

Acute mesenteric ischaemia is a syndrome caused by inadequate blood flow through the mesenteric vessels, resulting in ischaemia and eventual gangrene of the bowel wall. Although relatively rare, it is a potentially life-threatening condition. The maintenance of haemodynamic stability, along with adequate oxygen saturation, and the correction of any electrolyte imbalance, are of the utmost importance. However, nicotinamide adenine dinucleotide (NAD) biosynthesis modulation by precursor introduction can also be a powerful tool for preventing injury. Nicotinamide riboside is a pyridine-nucleoside form of vitamin B3 that functions as a precursor to NAD+ . The present study investigated nicotinamide riboside's effect on endothelium functional state, microcirculation and intestinal morphology in acute mesenteric ischaemia and reperfusion. Mesenteric ischaemia was simulated after the adaptation period (15 minutes) by occluding the superior mesenteric artery for 60 minutes, followed by a reperfusion period of 30 minutes. The functional state of intestinal microcirculation was evaluated by laser Doppler flowmetry. Endothelial functional activity was studied by using wire myography. Intestinal samples were stained with haematoxylin and eosin for histological analysis. The results revealed that nicotinamide riboside protects the intestinal wall from ischaemia-reperfusion injury, as well as improving the relaxation function of mesenteric vessels. Nicotinamide riboside's protective effect in small intestine ischaemia-reperfusion can be used to reduce ischaemia-reperfusion injury, as well as to preserve intestinal grafts until transplant.