The relationship between alveolar PO2 and the rate of O-demethylation of p-nitroanisole, a model substrate for cytochrome P-450 -linked mixed-function oxidation, was evaluated in the isolated rabbit lung perfused with Krebs-Ringer bicarbonate buffer. The appearance of the product, p-nitrophenol, in the pulmonary perfusate was measured spectrophotometrically, The PO2 of the ventilating gas was v...

Pretreatment of phenylephrine (0.5 microM)-preconstricted, isolated perfused kidneys of the male rat with indomethacin (2.8 microM) or BM 13.177 (20 microM) abolished the vasoconstrictor response to arachidonic acid (AA), uncovering a vasodilator response. BW 755C (25 microM), a dual cyclooxygenase/lipoxygenase inhibitor, did not modify the vasodilator effect of AA, whereas 5,8,11,14-eicosatetr...

The visibility of a target stimulus can be suppressed (inhibition) or increased (facilitation) during paracontrast masking. Three processes have been proposed to be involved in paracontrast masking: brief inhibition, facilitation, and prolonged inhibition (Breitmeyer et al., 2006). Brief inhibition is observed when the mask precedes the target at short stimulus onset asynchronies (SOAs) ranging...

The availability of potent combination antiretroviral regimens has resulted in a dramatic reduction in HIV-1 associated morbidity and mortality in the developed world. However, HIV infection and treatment has been associated with the development of insulin resistance, glucose intolerance and diabetes. Besides, there can be co-morbid situations of HIV infection and diabetes. Safe pharmacological...

The role of arachidonic acid metabolism and nitric oxide (NO) in hypoxia-induced changes of vascular tone was investigated in first-order cannulated rat cremaster muscle resistance arteries. Spontaneous tone reduced arterial diameter from 179 ± 2 μm (fully dilated) to 98 ± 3 μm under normoxia ([Formula: see text] = 150 mmHg). Hypoxia ([Formula: see text] 5-10 mmHg) had no significant effect on ...

Three highly purified forms of rat liver microsomal cytochrome P-450 (P-450,, P-45Ob, P-450,) are shown to be distinct proteins based on comparisons of their amino acid compositions, automated sequence analyses of the first 19 amino acids, and carboxypeptidase analyses of the COOH-terminal sequences. These three forms of cytochrome P-450 were purified from liver microsomes of rats pretreated wi...

conclusions all plants could inhibit mushroom tyrosinase, but more investigations on human tyrosinase and clinical studies are needed. results the hydroalcoholic extract of p. alkekengi showed the most tyrosinase inhibitory effect with ic50 of 0.09 mg/ml vs. 0.38, 0.38 and 2.82 mg/ml of b. persicum, a. rosea and m. vulgare, respectively. m. vulgare exhibited uncompetitive inhibition and other p...