3-Hydroxybutyrate co-infused with noradrenaline decreases resulting plasma levels of noradrenaline in Wistar rats

• Published in: Journal of experimental biology Vol. 200; no. Pt 20; pp. 2641 - 2646
• Main Authors: Cañas, N, Sanchis, D, Gómez, G, Casanovas, J M, Artigas, F, Fernández-López, J A, Remesar, X, Alemany, X
• Format: Journal Article
• Language: English
• Published: England 01.10.1997
• Subjects: 3-Hydroxybutyric Acid; Animals; Body Temperature; Hydroxybutyrates - administration & dosage; Infusions, Intravenous; Male; Norepinephrine - administration & dosage; Norepinephrine - blood; Rats; Rats, Wistar
• ISSN: 0022-0949; 1477-9145
• DOI: 10.1242/jeb.200.20.2641

Pentobarbital-anaesthetized male Wistar rats were infused with 6microgkg-1min-1 of noradrenaline. The infusion was supplemented with 8.5 mgkg-1min-1 of D-3-hydroxybutyrate (3-OHB) for 15 min in order to determine its effect on the adrenergic response of the rat. Plasma levels of noradrenaline rose to a plateau of approximately 50 nmoll-1 with infusion. In the group infused with noradrenaline alone, noradrenaline levels were maintained for 1h. Supplementation with 3-OHB induced a decrease in plasma noradrenaline level that was inversely correlated with 3-OHB level. Aortic and interscapular brown adipose tissue temperatures increased with noradrenaline infusion, but the rise was arrested by 3-OHB; replacing 3-OHB with glucose had no effect. Infusion of saline, glucose or 3-OHB in the absence of noradrenaline did not induce a rise in temperature in either tissue. Blood 3-OHB concentration increased to 1.2 mmoll-1 during 3-OHB infusion, decreasing rapidly at the end of infusion. Blood glucose levels increased with noradrenaline infusion; the presence of high 3-OHB levels decreased glucose concentration. The effects observed were transient and dependent on 3-OHB concentration; these effects may help explain most of the other effects of noradrenaline described here. The role of 3-OHB as a regulator of adrenergic responses seems to be part of a complex fail-safe mechanism which prevents wasting.