In humans, the glucagon response to moderate-to-marked insulin-induced hypoglycemia (IIH) is largely mediated by the autonomic nervous system. Because this glucagon response is impaired early in type 1 diabetes, we sought to determine if these patients, like animal models of autoimmune diabetes, have an early and severe loss of islet sympathetic nerves. We also tested whether this nerve loss is...

The sympathetic nervous system plays an important role in some forms of human hypertension as well as the Dahl salt-sensitive rat model of hypertension; however, the sympathetic targets involved remain unclear. To address this, we examined the role of the renal and splanchnic sympathetic nerves in Dahl hypertension by performing sham surgery (n=10) or targeted sympathetic ablation of the renal ...

In further illustration of Langley's generalisation that the effect of adrenalin upon plain muscle is the same as the effect of exciting the sympathetic nerves supplying that particular tissue, it is found that the urethra of the cat is constricted alike by excitation of the hypogastric nerves and by the injection of adrenalin. The sacral visceral nerves, on the other hand, relax the urethra of...

Autonomic nerves distribute by a variety of methods. They are recognized as components of all spinal and some cranial nerves, but they also have a strong tendency to exhibit a hitch-hiker relationship to arteries and to other nerves. The perivascular plexuses of the head and neck, and of the thorax and abdomen, are especially typical of peripheral sympathetic distribution. In the parasympatheti...

as the sympathetic neurohormone has evolved fronm much impressive circumistantial evidence; however, it has not been demonstrated that the biosynthesis of norepinephrine takes place in the sympathetic nerves and ganglia. This paper shows, through the use of labeled precursors, that the sympathetic nerves and ganglia synthesize norepinephrine in a systematic sequence from tyrosine and that this ...

Stretching the atria in anesthetized dogs produces reflex changes in heart rate, and in cardiac and renal sympathetic nerve activity. Anemic decerebration, cord transection at C4-C5, and severance of vagal or sympathetic cardiac nerves was done to identify the pathways and centers essential for these reflexes. Stretching the right atrium produced an aceleration of the heart and a definite incre...

WHAT KIND OF WORLD is it where some postganglionic sympathetic nerves secrete acetylcholine and where norepinephrine in conjunction with neuropeptide Y facilitates a key vasodilator response? It is the upside-down world of the human skin that possesses perhaps the most complex regional circulation in nature. Skin responds to environmental stimuli in ways that might be described as beautiful and...

Neuropathies involving the brachial plexus, phrenic, recurrent laryngeal, and saphenous nerves, as well as the sympathetic chain are complications of cardiac surgery. The reported frequency of nerve injuries varies from 1.5% to 24% for the brachial plexus and 10% to 60",,6 for the phrenic nerve (1-5). Neuropathies of the recurrent laryngeal, lower limb (saphenous) nerves, and the sympathetic ch...

The neural control of arteries and veins involves interactions between several vasoactive neurotransmitters released from the postganglionic sympathetic nerves and spinal sensory nerves. Sympathetic nerves are primarily vasoconstrictor in their action while the sensory nerves are vasodilatory; a result of the neurotransmitters released by these nerves. Thus, the nervous regulation of the vascul...

Previous studies from our laboratory have shown that the cardiac sympathetic afferent reflex is enhanced in dogs with experimental heart failure. The aim of the present study was to determine if the central gain of the cardiac sympathetic afferent reflex was also enhanced in dogs with heart failure. Fifteen dogs with pacing-induced heart failure were used in this study. Seventeen sham-operated ...