Background: The application of cold is the most common treatment of traumatic soft tissue injuries in order to decrease bleeding and swelling, but the appropriate time without existing of reactive VASODILATATION is not clear.Methods and materials: The survey was performed to detect the reactive VASODILATATION and to measure the skin impedance after 20-minutes cold gel pack application.Results: 70 healthy people (39 males & 31 females) with mean age of 24.81±3.41 were evaluated. Cold gel pack was applied to anterior aspect of their forearms for 20 minutes. The current intensity of skin was recorded by digital multi meter, before, during & after the cold application. Then skin impedance was calculated by Ohms rule. Statistical analyses of the data were done with paired T-test.Significant increase was found in skin impedance before and after cold application. That this increase was noted during the first 15 minutes after cold gel application, reactive VASODILATATION during 20 minutes cold gel pack application was not observed.Conclusions: These finding revealed that 20- minutes cold gel pack application decreased in blood volume, therefore the clinical use of cold on this time can reduce in local circulation such as in the management of acute-phase soft tissue trauma.

Background and Aim: Falcaria vulgaris locally named Paghazah has been used traditionally as a herbal medicine and as a vegetable in the west of Iran. Effects of the plant extract on the isolated rat heart including VASODILATATION have been shown in our previous study. The aim of this study was to assess thoroughly the effect of the plant on VASODILATATION, role of the nitric oxide as one of the most important mechanisms of VASODILATATION, and the potential cytotoxic effect of this herbal medicine on the isolated rat heart.Material and Methods: Hearts of male Wistar rats were isolated and perfused under constant pressure according to Langendorff method. Extract of the plant was prepared by soaking it in 70% ethanol according to percolation method. The rats were assigned into three groups. In one group (n=8) concentrations of 0.2, 1 and 5 microgram/ml of the extract were infused into the hearts over a period of 5 minutes and different cardiac parameters were measured and recorded. In the second group (n=8) 15 mg and 22.5 mg of the extract were used as bolus injections by ten minute intervals. Then the above mentioned doses were injected again into the hearts treated with LNAME (100micmol). In the third group, at first the hearts were treated with LNAME, then 15 mg and 22.5 mg of extract were injected.Results: Results of this study showed that infusion of concentrations of 0.2, 1 and 5micgr/ml of the extract significantly increased coronary solution flow (CSF) from the third to the fifth minute after infusion (P<0.05). Following injection of 15 mg and 22.5 mg of extract, CSF increased significantly from 10.58±0.63 and 9.66±0.52 ml/min to 13.76±0.51 and 12.18±0.64 respectively (P<0.05). Also similar significant increases in CSF changes were seen in the presence of LNAME (P<0.05) which indicated nitric oxide played no role in this mechanism. Amount of LDH released after bolus injection of the extract did not significantly differ from its amount in the control group.Conclusion: In the present study we emphasize that the coronary vasodilator effect of Falcaria vulgaris hydro alcoholic extract in the isolated rat heart is significant. Nitric oxide is not involved in this mechanism. Considering the time and wide range of administrated doses (infusion method) and reversible effect of the extract it can be regarded harmless. Also on the basis of LDH measurement it has no cytotoxic effect. In our study nitric oxide had no role in coronary VASODILATATION. Therefore evaluation of other mechanisms of VASODILATATION brought into play by the extract is recommended.

Introduction: Considering the higher incidence of atherosclerosis and cardiovascular disorders in diabetes mellitus and the role of vasorelaxation disturbance in the development of these complications, this study was conducted to evaluate the effect of two-month oral administration of Marrubium vulgare (MV) on the vasorelaxation response of isolated aorta in experimental model of diabetes mellitus in rats.Methods: In this experimental study, 32 male Wistar rats were randomly divided into four groups: control, MV-treated control, diabetic, and MV-treated diabetic groups. For induction of diabetes, streptozotcin (STZ) was intraperitoneally administered (60mg/kg). MV-treated groups received MV mixed with standard pelleted food at a weight ratio of 1/15. After 2 months, relaxation response of KCI-and noradrenaline-precontracted aortic rings was determined after addition of acetylcholine using isolated tissue setup.Results: Comparing to one week before test serum glucose level showed a significant increase in diabetic group at 4th and 8th weeks (P<0.001), while this increase was not observed in MV-treated diabetic group. In addition, the latter group showed a higher vasorelaxation in KCI-and noradrenaline-precontracted rings (P<0.05) as compared to diabetic group. Meanwhile, there was no significant difference between control and MV-treated control groups regarding relaxation response.Conclusion: It can be concluded that oral administration of MV for 2 months could improve the vasorelaxation response of the vascular system and this may prevent the development of hypertension in diabetic rats.

BACKGROUND: There is a high mortality rate in cyanotic patients with congenital heart disease (CHD) due to cardiovascular complications. The cardiovascular prognosis is negatively affected by endothelium dysfunction, increased arterial stiffness, and impaired vascular system. This study aimed to determine carotid intimal mean thickness (CIMT) and flow-mediated dilatation (FMD) in a group of children with cyanotic CHD (CCHD).METHODS: FMD and CIMT were evaluated for 45 children with CHKD and 38 patients who did not have CHKD over the period 2021 to 2022, as part of this case-control study. In terms of age and gender, the case group has been compared to controls.RESULTS: Men accounted for 61.3% of the participants, with a mean standard deviation age of 7.8  5.39 years. In subjects with CCHD, CIMT increased non-significantly and FMD decreased significantly, but systolic blood pressure was significantly higher in patients than in the healthy group. (P=0.003).CONCLUSION: FMD was reduced in children with CCHD, but in controls, systolic blood pressure and CIMT were lower. The risk of developing atherosclerosis in CCHD patients may be increased by an increase in CIMT and systolic blood pressure.

Background: The mechanisms underlying cerebral VASODILATATION during hypercapnia are not fully understood. Objective: To examine the role of nerves and prostaglandins in the regulation of basal blood flow and in hypercapnia-induced VASODILATATION in the cerebral blood vessels of rabbit. Methods: Cerebral blood flow was measured by laser Doppler flowmeter in 18 NZW rabbits anesthetized with sodium pentobarbital. Tetrodetoxin was administered locally and indomethacin (a prostaglandin inhibitor) both locally and systemically before and during induction of hypercapnia. Results: Basal cerebral blood flow did not change significantly in response to local tetrodetoxin, and also after local and systemic administration of indomethacin. Hypercapnia increased cerebral blood flow by 25.9±3.9% before and by 24.3±6.5% after administration of TTX and by 22.1±7.1% before and by 18.2±6.3% after administration of indomethacin. Conclusion: In the rabbit, prostaglandin and regional nerves had no role in regulation of basal cerebral blood flow, nor did they contribute to cerebral vascular dilatation during hypercapnia.

Adenosine 3', 5'-cyclic monophosphate (cAMP)-mediated pulmonary vascular smooth muscle relaxation is a principal mechanism of pulmonary vasomotor control. The purpose of this study was to compare the potency and efficacy of the following receptor-linked pathway for pulmonary vasorelaxation which are mediated by cAMP. The experiments were performed on the rat pulmonary artery rings using vasorelaxants including isoproterenol (ISO, ß2-adrenoceptoragonist), adenosine (AD, P1-purinoceptor agonist), adenosine 5' -diphosphate (ADP, P2-purinoceptor agonist), adenosine 5'- triphosphate (ATP, P2-purinoceptor agonist), and histamine (HIST, H2-histamine receptor agonist). All of these drugs induced dose-dependent relaxation in the rat artery rings precontracted with phenylephrine (100 nM) (PE, EC75). Dose-response curves for rat pulmonary artery rings were recorded isometrically with Grass FT03 transducers and displayed on a Grass model 7 polygraph. The results showed that ISO (100 pM to 10 µM), AD (30 µM to 100 µM), ADP and ATP (10 nM to 10 µM) and HIST (1 µM to 100 µM) induced dose-dependent relaxation in rat pulmonary artery rings. The maximum responses were for ISO, ADP and A1P (10 µM), AD (10 µM) and HIST (1 mM). In the preparations The maximum relaxant responses were for ISO (93.04±1.25%), ADP (78.39±2.68%), ATP (80.48±1.93%), AD (72.22±3%), and HIST (69.52±4.02%) respectively. The median effective concentrations (EC50) were 0.01 µM Physiology and Pharmacology Volume 4, Number 2 Fall & Winter 2000-2001 for ISO, 0.5 µM for ADP, 0.6 µM for ATP, 70 µM for AD, and 100 µM for HIST. These data revealed that although receptor-linked pathways and their activation of adenylate cycles and ensuing increased level of cAMP are responsible for relaxation in the artery rings, but there existed significant differences regarding potency and efficacy.

Background: The mechanisms underlying cerebral hypercapnic VASODILATATION are not fully understood.Objective: To investigate the role of nitric oxide (NO) and ATPsensitive potassium (KATP) channels in basal blood flow regulation and hypercapnia-induced VASODILATATION in rabbit cerebral blood vessels. Methods: The change in cerebral blood flow was measured by a laser Doppler flowmeter in 18 New Zealand white rabbits, in two groups, under general anesthesia with sodium pentobarbital. Nomega- nitro-L-arginine methyl ester (L-NAME) and glibenclamide were administered locally and systemically before and during induction of hypercapnia.Results: The change in cerebral blood flow was not significant following local and systemic L-NAME administration, showing a nonsignificant role of local and systemic NO in regulation of rabbit basal cerebral blood flow. Hypercapnia increased cerebral blood flow by 17.3±4.4% before and 17.3±5.8% after local, and 5.8±3.2% (p<0.05) after systemic L-NAME administration. The change in cerebral blood flow was not significant after local and systemic administration of glibenclamide indicating a lack of KATP channel role in basal blood flow regulation. Hypercapnia increased cerebral blood flow by 27.2±8.7% before and 24.7±6.4% after local, and 49.3±9.7% after systemic administration of glibenclamide (p: NS in both cases).Conclusion: Regional NO production had no role in basal cortical blood flow regulation and systemic NO contributed to 66% increment in cerebral blood flow during hypercapnia. Also, the KATP channels did not mediate the effect of NO or other vasodilators responsible for increasing cerebral blood flow during hypercapnia.