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Biomedical subjects

R E Weitzman

Publications and source records attributed to R E Weitzman.

43 records · Page 3Linked to original sources
PubMed1978

Is antidiuretic hormone elevated in psychosis? A pilot study.

Plasma antidiuretic hormone (ADH) measured by radioimmunoassay was higher in acutely psychotic subjects than in acutely anxious nonpsychotic subjects or normal subjects. ADH was not elevated in acutely anxious nonpsychotic subjects. ADH was positively correlated with degree of psychosis. Normal osmolar and volume regulatory mechanisms did not seem responsible for the ADH elevations in the psychotic subjects. Because ADH is both produced in the hypothalamus and can be accurately measured in blood, this substance may prove particularly valuable in the study of psychiatric disorders.

Anxiety↗
PubMed1977

Episodic secretion of arginine vasopressin.

The plasma arginine vasopressin (pAVP) response to osmotic stimulation was studied in dogs and sheep by sampling at frequent intervals during steady-state dehydration and during water diuresis. Frequent sampling also was conducted after continuous infusion or bolus injection of 5 or 20 g/100 ml NaCl. A pulsatile pattern of pAVP was observed after such infusions or injections and in some animals after water deprivation. This pattern was not seen after water loading or in mildly dehydrated animals. The short term changes in pAVP during continuous infusion of 5 g/100 ml NaCl could not be correlated with variations in plasma tonicity. Rather, they appeared to reflect discontinuous hypothalamic posterior pituitary release of AVP. Thirst was evoked by a lower dose of 5 g/100 ml NaCl than was required for consistent stimulation of pAVP release, and the thirst response frequently was observed prior to the peak AVP response after bolus injection of 5 and 20 g/100 ml NaCl.

Animals↗
PubMed1977

Log linear relationship between plasma arginine vasopressin and plasma osmolality.

The integrated plasma arginine vasopressin concentration (IpAVP) was determined by pooling the results of single samples collected every 3 min for 0.5 h in dehydrated, randomly hydrated, and water-loaded sheep. A linear relationship was observed between the log of the integrated AVP concentration and plasma osmolality. This relationship was tested by the bolus injection of 20 g/100 ml NaCl to both water-loaded and randomly hydrated sheep. The rise in the log of IpAVP divided by the rise in plasma osmolality was similar in both groups (P greater than 0.5) and was superimposable upon the regression line derived from steady-state observations. The data would suggest that AVP is released as an exponential function of plasma osmolality rather than as a threshold phenomenon.

Animals↗
PubMed1977

beta-Endorphin secretion of arginine vasopressin in vivo.

The effect of beta-endorphin upon plasma arg8-vasopressin release was studied in vivo in rabbits and in vitro in rat neural lobes. Following intravenous administration of 200 mug/kg synthetic beta-endorphin plasma AVP rose significantly by five minutes after injection and remained elevated for twenty-five minutes compared to controls. In contrast beta-endorphin had no significant effect on AVP release from isolated rat neural lobes in vitro. beta-Endorphin stimulates AVP secretion in vivo, but this is not due to a direct action upon the neural lobe.

Animals↗