Doctoral Dissertations

Date of Award

6-1981

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Psychology

Major Professor

James E. Lawler

Abstract

Behavioral influences on excretion of Na+ and H2O and on mean arterial blood pressure (MBP) were studied during saline diuresis in three unanesthetized adult female monkeys. Infusions of isotonic saline (70 ml/kg and 0.5 ml/min, iv) caused excretion of 195 ± 3 µl H2O/kg/min and 31.8 ± 3.0 µeg Na+ /kg/min. Inulin clearance (CIn) was 4.3 ± 0.1 ml/kg/min. Naloxone hydrochloride, an opiate receptor antagonist, had no effect on Na+ and H2O excretion or MBP. Electric shock (5 ma, 200 msec, 12/min for 30 min) delivered to the tail reduced excretion of Na+ and H2O to 84 ± 6% and 78 ± 6% of baseline values, but values returned to baseline before the end of the 30 min shock exposure. CIn decreased initially, then rose above baseline values. MBP increased 3.4% ± 2.5% during shock exposure. The role of opiate receptors in adaptation to electric shock was studied by administering naloxone (10 mg/kg, iv) immediately before electric shock was delivered. After naloxone, electric shock reduced Na+ and H2O excretion to 42 ± 10% and 44 ± 10% of baseline values, and delayed return to baseline values. CIn was decreased throughout the 30 minutes. MBP increases were slightly greater than increases in response to shock alone. Continuous broadband noise at 96 dB decreased Na+ and H2O excretion by 20%, but 108 dB noise had inconsistent effects. After naloxone, however, 108 dB noise decreased excretion of Na+ and H2O to 70 ± 17% and 62 ± 15% of baseline values. MBP decreased slightly in response to both levels of noise, but increased by 4% in response to noise after naloxone. Results of these experiments suggest that unconditional renal and blood pressure responses to noxious sensory stimuli are moderated by endogenous opiates.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS