Concentrations of indoleamine metabolic intermediates in the ventricular cerebrospinal fluid of advanced Parkinson's patients with severe postural instability and gait disorders.

Postural instability and gait disorders (PIGD) are the primary causes of disability in many but not all advanced Parkinson's disease (PD) patients. We have measured the concentrations of serotonin, 5-hydroxytryptophan (5-HTP), 5-hydroxy-3-indoleacetic acid (5-HIAA), and homovanillic acid (HVA) in samples of ventricular cerebrospinal fluid from ten PD patients with severe disability from PIGD and from ten PD patients with tremor and levodopa induced dyskinesia as their predominant motor dysfunction. The two groups were prospectively matched for duration of disease and age.

Regulatory mechanisms in endoluminal release of serotonin and substance P from feline jejunum.

The mechanisms controlling vagally induced 5-HT and SP release into the jejunal lumen were studied in the cat. In control animals, electrical vagal nerve stimulation doubled the rate of endoluminal secretion of 5-HT and SP. Propranolol pretreatment did not alter luminal secretion of these hormones.