The aim of this study was to investigate the influence of nitric oxide (NO) donors (S-nitroso-L-acetyl penicillamine, spermine-NO complex and sodium nitroprusside) and NO synthase inhibitors (N(omega)-nitro-L-arginine methyl ester, N(omega)-nitro-l-arginine, and (+/-)-2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine) on progesterone production by dispersed bovine luteal cells cultured for 24 h. All...

Neuronal nitric oxide synthase (NOS I) has been shown to generate nitric oxide (NO*) and superoxide (O(2)* during enzymatic cycling, and the ratio of each free radical is dependent upon the concentration of L-arginine. Using spin trapping and electron paramagnetic resonance spectroscopy, we detected alpha-hydroxyethyl radical (CH(3)*CHOH), produced during the NOS I metabolism of ethanol (EtOH)....

Superoxide (O-2) and nitric oxide (NO) act to kill invading microbes in phagocytes. In macrophages NO is synthesized by inducible nitric oxide synthase (iNOS, NOS 2) from L-arginine (L-Arg) and oxygen; however, O-2 was thought to be produced mainly by NADPH oxidase. Electron paramagnetic resonance (EPR) spin trapping experiments performed in murine macrophages demonstrate a novel pathway of O-2...

Vascular tissues express heme oxygenase, which metabolizes heme to form carbon monoxide (CO). CO promotes relaxation of vascular smooth muscle but also inhibits nitric oxide (NO) formation. This study examines the hypothesis that CO promotes endothelium- and NO synthase-dependent vasoconstriction of isolated arterioles. Studies were conducted on pressurized first-order gracilis muscle arteriole...

Two 29-residue peptides were prepared, one of which (ChPepz) was designed by surface-simulation synthesis to mimic the active site of alpha-chymotrypsin, and the other (TrPepz), which contained four substitutions relative to ChPepz, was fashioned after the active site of trypsin. Each peptide was cyclized by a disulfide bond. The ChPepz monomer effected hydrolysis of the ester group in N-benzoy...

A limited reduction of the disulfide bonds of bovine enterokinase (enteropeptidase, EC 3.4.21.9) was accomplished with 50 mM dithioerythritol, at pH 9.0, and at 4 degrees C. The conditions separated the heavy and light subunits quantitatively with improved reliability when compared to the conditions used previously (Savithri, H. S., and Light, A. (1980) Biochim. Biophys. Res. Commun, 94, 360-36...

Objective: Agmatine is an endogenous cationic amin and have been reported several neurotherapeutic effects through α2-adrenoceptors, imidazoline binding sites, inhibition of NMDA receptors nitric oxide (NO) synthase. NO was to act as a neuromodulator neurotransmitter in central nervous system has proconvulsant/anticonvulsant activities convulsion models. We aimed compare the anticonvulsant agma...

N-methyl-d-aspartate (NMDA) and non-NMDA excitatory amino acid (EAA) receptor subtypes are involved in the integration of visceral afferent inputs within the nucleus of the solitary tract (NTS). Microinjection studies indicate interactions between nitric oxide (NO) and EAA receptors within the NTS. To examine these interactions at the single cell level, this study characterized the effects of t...

Objective(s): Nucleus Raphe Magnus (NRM) that is involved in the regulation of body temperature contains nitric oxide (NO) synthase. Considering the effect of NO on skin blood flow control, in this study, we assessed its thermoregulatory role within the raphe magnus. Materials and Methods: To this end, tail blood flow of male Wistar rats was measured by laser doppler following the induction of ...

1. N-Benzoyl-L-serine methyl ester was synthesized and evaluated as a substrate for bromelain (EC 3.4.22.4) and for papain (EC 3.4.22.2). 2. For the bromelain-catalysed hydrolysis at pH 7.0, plots of [SO]/vi (initial substrate concn./initial velocity) versus [SO] are markedly curved, concave downwards. 3. Analysis by lattice nomography of a modifier kinetic mechanism in which the modifier is su...