letters to nature Page 1 letters to nature centred on the TV screen during the course of
studying each cell. We defined the size of each cell's receptive field centre by independently …

1. Experiments were carried out to quantify the stimulation‐evoked overflow of catecholamines
and purines (ATP, ADP, AMP and adenosine) from an in vitro sympathetic nerve‐smooth …

The purpose of the present study was to assess the possible sites which contribute to the
nerve stimulation- and alpha-agonist-induced overflow of endogenous adenine nucleosides …

Recent reports have suggested that sympathetic nerves may store separately and release
independently the cotransmitters ATP and norepinephrine (NE). It is conceivable therefore …

The effects of a number of purinoceptor agents on the release of endogenous noradrenaline
from the electrically stimulated rat caudal artery were determined. Noradrenaline was …

Dihydrofolate reductase has been purified from a methotrexate-resistant strain of Lactobacillus
casei NCB 6375. By careful attention to growth conditions, up to 2.5 g of enzyme is …

The effects of a number of purinoceptor agonists and antagonists on norepinephrine (NE)
overflow were examined in the electrically field-stimulated rat vas deferens. The P1 receptor …

The notion that one neuron synthesizes, stores, and releases only one transmitter has been
seriously questioned recently.'The possible existence of cotransmitters in postganglionic …

Noradrenaline-induced release of endogenous adenine nucleotides (ATP, ADP, AMP) and
adenosine from both rat caudal artery and thoracic aorta was characterized, using high-…

Electrical field stimulation of the rat caudal artery (0.5-ms pulses at 8 Hz for 3 min) results in
the release of norepinephrine (quantified by HPLC-electrochemical detection) and adenyl …