The aim of this study was to see whether increased activity of nitric oxide (NO) might account for decreased pulmonary vascular tone seen in the hyperdynamic circulation of cirrhosis. We compared the pulmonary vascular reactivity of isolated pulmonary arteries (PA) from control rats (n = 10), and rats with biliary cirrhosis (n = 10) induced by chronic bile duct ligation (4 weeks). The responses...

In the conversion of fuel in the Tehran Research Reactor core from Highly- Enriched Uraniutn to Low-Enriched Uranium fuel neutronics analysis, thermal hydraulic calculations and kinetic performance of the core have to be studied. In this study, static and dynamic core performance for HEU and LEU fuels were investigated. In static conditions, two groups of neutron flux distributions in axia...

The renal vasculature of Wistar Kyoto spontaneously hypertensive rats (SHR), prior to (4-5 week) and during established hypertension (21 week) and those of age-matched Wistar Kyoto normotensive rats (WKY) were morphometrically and pharmacologically studied. Under dilated conditions, the vascular resistances (RVR) of the isolated kidneys of young and adult SHR were similar to WKY. Morphometric m...

To the Editor: The article by Feng et al1 caused a revolution in current thinking regarding the pathomechanism involved in myocardial stunning, in that it irrefutably proved that there is no causal link between troponin I (TnI) degradation and the transiently depressed contractile function after a brief ischemic episode. However, does this fact imply that there is no answer to the question of w...

Objective Abnormal uterine contraction patterns were recently demonstrated in uterine strips from pregnant women treated with Levothyroxine (T4). These abnormalities were correlated with an increased risk of C-section delivery and associated surgical complications. To date, no study has investigated whether uterine contractility is modified by hypothyroidism or T4 treatment. Herein, we analyze ...

BACKGROUND Cigarette smoke exposure is strongly associated with airway hyperreactivity (AHR) which is the main characteristic seen in asthma. The intracellular MAPK signaling pathways are suggested to be associated with the airway damage to the AHR. In the present study, we hypothesize that secondhand cigarette smoke (SHS) exposure upregulates the bronchial contractile receptors via activation ...

Hyperthyroidism is characterized by increased vascular relaxation and decreased vascular contraction and is associated with augmented levels of triiodothyronine (T3) that contribute to the diminished systemic vascular resistance found in this condition. T3 leads to augmented NO production via PI3K/Akt signaling pathway, which in turn causes vascular smooth muscle cell (VSMC) relaxation; however...

The effects of corticosteroids on vascular tone have been recognized since the 1940s. However, despite repeated demonstration of pharmacological effects both in vitro and in vivo, their physiological significance as regulators of tone in health remains to be established. Evidence that abnormal vascular reactivity is important when adrenal steroid production is deranged is more convincing, and p...

Regional heterogeneity exists in reactivity of different vascular beds to vasoactive substances. Experiments were designed to determine if there are differences between thoracic and abdominal aorta response to acetylcholine-induced relaxation. Ten male Sprague-Dawley rats with a weighing between 200g-250g were used. The aorta was isolated and 3mm aortic rings were cut and suspended in organ bat...

BACKGROUND AND PURPOSE The goal of this study was to determine the alterations in contractile and dilatory responses and ultrastructure of the feline middle cerebral artery after hemorrhagic hypotension. METHODS In the sodium pentobarbital anesthetized cats, a steady 50 mm Hg level of hypotension was reached by bleeding into a reservoir and maintained at this level by further bleeding or auto...