Excitation of dorsal motor vagal neurons evokes non-nicotinic receptor-mediated gastric relaxation.

Vagal stimulation results in both gastric motor excitatory and non-adrenergic non-cholinergic (NANC) inhibitory responses. The NANC pathway involves preganglionic cholinergic neurons, which act through nicotinic receptors to ultimately evoke gastric smooth muscle relaxation via release of nitric oxide (NO) and other neurotransmitters. Within the dorsal motor nucleus of the vagus (DMN), some preganglionic neurons also contain NO synthase.

Molecular recognition between oligopeptides and nucleic acids: DNA binding selectivity of a series of 1,2,4-triazole-containing lexitropsins.

The synthesis of a series of 1,2,4-triazole-containing oligopeptide lexitropsins related to the natural antitumor antibiotic distamycin is described. The binding properties of these new agents to both native DNAs and synthetic polydeoxyribonucleotides were determined by UV absorption and circular dichroism studies. The DNA binding and sequence selectivity of these agents have been determined by complementary strand MPE footprinting on two restriction fragments of pBR322 DNA.

Novel linked antiviral and antitumor agents related to netropsin and distamycin: synthesis and biological evaluation.

A group of oligopeptides have been synthesized which are structurally related to the natural antiviral antitumor antibiotics netropsin and distamycin bearing two such moieties linked by polymethylene bridges. Cytostatic activity against both human and murine tumor cell lines and their in vitro activity against a range of viruses are reported. Enhanced antiviral activity was obtained against vaccinia virus.

Variation of DNA sequence specificity of DNA-oligopeptide binding ligands related to netropsin: imidazole-containing lexitropsins.

CD binding studies of nonintercalative oligopeptides related to netropsin, named lexitropsins, have been carried out with synthetic duplex DNAs and natural DNA. While netropsin possesses a high dA.dT sequence specificity, these ligands show a progressive lowering of the ability to bind to dA.

Molecular recognition between oligopeptides and nucleic acids. Specificity of binding of a monocationic bis-furan lexitropsin to DNA deduced from footprinting and 1H NMR studies.

MPE-Fe(EDTA) footprinting of a novel monocationic bis-furan lexitropsin 6 on a HindIII/EcoRI restriction fragment of pBR322 DNA revealed a series of four-base binding sites (all 5'----3') of (primary) TGTA, TGAA, AAAT, ACAA, TTAT, and (secondary) CTAA, TCGT, TGTA, GTCA, and GGTT. Thus 6 can accept a GC pair at positions 1, 2 or 3 of the binding site with a strict 3' (4 position) AT requirement. Marked enhancement of cleavage, particularly at GC rich sequences, is observed at regions flanking or even up to 18 base pairs remote from a given binding site.