The neurotransmitter(s) underlying nitric oxide synthase (NOS)-independent neural inhibition in the internal anal sphincter (IAS) is still uncertain. The present study investigated the role of purinergic transmission. Contractile and electrical responses to electrical field stimulation of nerves (0.1-5 Hz for 10-60 s) were recorded in strips of mouse IAS. A single stimulus generated a 28-mV fas...

Whole-cell patch clamp recordings were performed on hypoglossal motoneurons (HMs) in a brain stem slice preparation from the neonatal rat. The medium afterhyperpolarization (mAHP) was the only afterpotential always present after single or multiple spikes, making it suitable for studying its role in firing behavior. At resting membrane potential (-68.8 +/- 0.7 mV), mAHP (23 +/- 2 ms rise-time an...

To investigate the mediators of bradykinin-induced vasorelaxation in human coronary microarteries (HCMAs), HCMAs (diameter approximately 300 microm) obtained from 42 heart valve donors (20 men and 22 women; age range, 3 to 65 years; mean age, 46 years) were mounted in Mulvany myographs. In the presence of the cyclooxygenase inhibitor indomethacin, bradykinin relaxed preconstricted HCMAs in a co...

27 Parasympathetic cardiac motoneurons (PCMNs) in the nucleus ambiguus (NA) 28 play a key role in regulating cardiac functions. In this study, we examine the effects of 29 maternal diabetes on excitability, action potential (AP) properties, and small 30 conductance Ca 2+-activated K + (SK) currents of PCMNs. Neonatal mice from diabetic 31 (OVE26 female, NMDM) and normal (FVB female, control) mo...

The possible roles of endothelial intracellular Ca(2+) concentration ([Ca(2+)](i)), nitric oxide (NO), arachidonic acid (AA) metabolites, and Ca(2+)-activated K(+) (K(Ca)) channels in adrenergically induced vasomotion were examined in pressurized rat mesenteric arteries. Removal of the endothelium or buffering [Ca(2+)](i) selectively in endothelial cells with BAPTA eliminated vasomotion in resp...

Indirect evidence suggests that ATP is a neurotransmitter involved in inhibitory pathways in the neuromuscular junction in the gastrointestinal tract. The aim of this study was to characterize purinergic inhibitory neuromuscular transmission in the human colon. Tissue was obtained from colon resections for neoplasm. Muscle bath, microelectrode experiments, and immunohistochemical techniques wer...

1. The nonpsychoactive cannabinoid abnormal-cannabidiol (trans-4-[3-methyl-6-(1-methylethenyl)-2-cyclohexen-1-yl]-5-pentyl-1,3-benzenediol) (abn-cbd) produced concentration-dependent relaxation of methoxamine-precontracted rat small mesenteric artery. Endothelial removal reduced abn-cbd potency six-fold without affecting the maximum relaxation. 2. In endothelium-intact vessels, abn-cbd was less...

We investigated the spontaneous activity and properties of freshly isolated ventral tegmental area (VTA) principal neurons by whole cell recording and single-cell RT-PCR. The VTA principal neurons, which were tyrosine hydroxylase-positive and glutamic acid decarboxylase (GAD67)-negative, exhibited low firing frequency and a long action potential (AP) duration. The VTA principal neurons exhibite...

Parasympathetic cardiac motoneurons (PCMNs) in the nucleus ambiguus (NA) play a key role in regulating cardiac functions. In this study, we examined the effects of maternal diabetes on excitability, action potential (AP) properties, and small conductance Ca(2+)-activated K(+) (SK) currents of PCMNs. Neonatal mice from diabetic (OVE26 female, NMDM) and normal (FVB female, control) mothers that h...