Experiments conducted in recent years on animals and research works worldwide show a linkage between calprotectin and occurrence and development of the abdominal aortic aneurysm (AAA). Additionally, a correlation between the level of the receptor for advanced glycation end products (RAGE) and the diameter of the abdominal aorta was found. The purpose of this study was to investigate whether calprotectin and the RAGE plasma level may be a biomarker of human AAA occurrence. We determined two groups of research participants: a group of 32 patients aged 53–88 undergoing primary endovascular aneurysm repair and a control group of 43 volunteers aged 59–82 without the AAA. All the patients from the study group had their blood samples drawn in order to determine the level of calprotectin and RAGE in plasma. The second follow-up examination was carried out after three months. The concentration of calprotectin and RAGE in plasma was determined with the use of the immunoenzymatic method (ELISA). The study showed that patients with the AAA had significantly higher mean calprotectin and RAGE plasma levels (p = 0.0001 and p = 0.0002, respectively) as compared to the control group. After the AAA repair operations, the level of concentration of the calprotectin decreased significantly (p = 0.0002). So far, no studies on the connection between the increase of the calprotectin and RAGE in the patient’s plasma with the AAA have been published. Calprotectin may be a promising biomarker related to the occurrence of AAA. Larger studies are needed to fully elucidate and confirm the role of calprotectin in the development and progression of the aneurysm.

â-adrenergic antagonists influence abdominal aorta contractility by mechanisms not involving â-adrenergic receptors. Folia Biologica (Kraków) 62: 243-250. â-adrenergic receptors (â-AR) are widely distributed in the cardiovascular system, where they considerably contribute to the control of its functions. â-blockers are commonly used in the treatment of disorders of the circulatory system. They act primarily by inhibiting cardiac â-receptors. However, there are also reports of pleiotropic action of â-blockers as well as of new compounds created to study â 3 adrenergic receptors. The study aimed to investigate additional mechanisms of action of â-AR inhibitors in the rabbit abdominal aorta with emphasis on their action on á-adrenergic receptors and calcium influx. Responses to propranolol, betaxolol, metoprolol and SR59230A were evaluated in phenylephrine and PGF 2alpha precontracted aortic rings. The effect of propranolol on the phenylephrine concentration-contraction curve was examined. Propranolol ($10 FM) and SR59230A ($0.1 FM) induced relaxations in phenylephrine-precontracted rings, while betaxolol and metoprolol had little effect. The â-AR inhibitors produced further contraction of tissues preincubated with PGF 2alpha , excluding SR59230A, which after initial contraction, elicited marked relaxation at a concentration above 1 ìM. 100 FM of propranolol caused a significant rightward shift of the concentration-contraction curve to phenylephrine with no reduction in the maximum response. Incubation of aortic rings in phentolamine reduced the maximal contraction to propranolol; verapamil pretreatment by contrast enhanced contractile response. In conclusion, SR59230A and propranolol most probably act as á 1-AR competitive antagonists in the presence of phenylephrine in rabbit abdominal aortic rings. After á-ARs blockade, propranolol exerts a weak relaxing activity connected with Ca 2+ channel inactivation. SR59230A at a high concentration acts on the rabbit aorta by an additional mechanism needing further investigation.

Background: Abdominal aortic aneurysm (AAA) remains a surgical challenge. There are many recognizable markers associated with the formation of AAA. Previous experiments carried out on animal models have shown a correlation between serum calprotectin and the occurrence of AAA. Objective: This study aimed to evaluate the level of calprotectin as a potential diagnostic biomarker in patients with diagnosed AAA. Method: The study group consisted of 75 patients aged 35–75 years who were assigned to two groups: a control group (n=43) of healthy subjects without AAA and a study group (n=32) of patients with a diagnosed AAA. The first calprotectin test was performed upon patient admission to the hospital, and the second control test was performed after three months. The concentration of calprotectin in plasma was determined using the immunoenzymatic method (ELISA) with the commercially available Assaypro Kit (AssayMax™ Human Calprotectin ELISA Kit), as well as the sandwich method with polyclonal antibodies to human calprotectin and peroxidase enzyme. Results & Discussion: Serum calprotectin levels in AAA patients were three times higher than in healthy subjects (p<0.05). A statistically significant a twofold decrease in calprotectin concentration was observed after AAA surgery in comparison with the control group (p<0.05). Conclusion: Calprotectin levels can be an important marker in the detection of AAA. In conclusion, AAA patients showed a threefold increase in serum calprotectin level and a twofold decrease in this marker after AAA surgery.

Investigation of the effect of α 1 -adrenergic receptor subtypes on the contraction of the abdominal aorta will allow for more effective treatment of hypertension by use of selective antagonists. The aim of the study was to evaluate the participation of α 1 -adrenergic receptor subtypes in the contractility of the aortic smooth muscle cells in rabbits. The in vitro experiments were performed in isolated tissue preparations from 30 adult female New Zealand rabbits. The abdominal aortic sections were placed in organ bath chambers and contracted with increasing doses of non-selective α 1 -adrenergic receptor agonist phenylephrine without pre-incubation or after incubation in α 1 -adrenergic receptor subtype-selective or non-selective antagonists. Separate sections were incubated with increasing concentrations of antagonists. Phenylephrine caused maximal rise in arterial smooth muscle tone to 4.75 ± 0.47 mN. The most potent in blocking phenylephrine induced contraction was 5-metylurapidil (α 1A -adrenergic receptor antagonist) followed by phentolamine and prazosin (non-selective α 1 -adrenergic receptor antagonists); BMY 7378 (α 1D -adrenergic receptor antagonist), cyclazosin and L-765.314 (α 1B -adrenergic receptor antagonists) were less effective. All antagonists, except BMY 7378 elicited relaxation of nonprecontracted aorta in dose dependent manner. Our results indicate that postsynaptic α 1A receptors are the most potent in producing rabbit abdominal aorta contraction, while α 1B and α 1D subtypes are less effective.

No abstract

The aim of the study was to demonstrate the effect of selected agonists and antagonists of alpha-adrenergic receptors on muscle contractility of the rabbit abdominal aorta in vitro with particular emphasis on alpha2-adrenergic receptor subtypes. The study was conducted on 30 New Zealand breed rabbits from which specimens of the abdominal aorta were collected. The sections were set up in an automatic water bath in a Krebs-Henseleit buffer at 37 degrees C. The experiments showed that alpha1-adrenergic receptors played the main role in the contractile response ofthe rabbit abdominal aorta. Stimulation of alpha1-adrenergic receptor by administration ofphenylephrine resulted in an increase in smooth muscle tonus ofthe rabbit abdominal aorta by an average of 4.75 mN. The reaction after stimulation of alpha2-adrenergic receptors by similar doses of their agonists was much weaker. Prolonged tissue response time and time needed to reach maximum tonus for alpha2-adrenergic receptor agonists were observed. The obtained results confirm the thesis that the alpha1-adrenergic receptor is the most important factor controlling the contractility of the rabbit abdominal aorta, but the alpha2-adrenergic receptor is also involved in maintaining muscle tissue tonus.

The study was conducted on 5 pigs weighing 20-30 kg. Bipolar electrodes were surgically implanted into the muscular layer of the vascular smooth muscle cell of the abdominal aorta just below the renal arteries. Myoelectric activity characterized by the appearance of changes of membrane potential was found. Changes of potential could be divided according to the amplitude, duration and frequency into first-, second-and third-order waves. First-order waves appeared with a mean frequency of 128 ± 14/min. The mean wave amplitude was 0.150 ± 0.03 mV, and the mean duration was 0.43 ± 0.05 s. They were closely correlated with the electrocardiogram and blood pressure changes. Second-order waves appeared with a mean frequency of 15.9 ± 4.4/min. They were characterized by a mean duration of 2.69 ± 1.5 s. The mean amplitude of the discharge was 0.205 ± 0.157 mV for the second-order wave, they were correlated with the animal's respiratory action. Third-order waves appeared with a mean frequency of 4.03 ± 1.07/ min. They were characterized by a mean duration of 11.81 ± 5.3 s. The mean amplitude of the discharge was 0.345 ± 0.232 mV for the third-order wave and they were associated with the autonomic control of the lumen of the blood vessel. For the first time the usefulness of the electromyography method in monitoring changes in the vascular smooth muscle cell of pig abdominal aorta was proved.

No abstract