Ethanol and Stress Activate Catecholamine Synthesis in the Adrenal

Abstract

Ethanol consumption and mental stress activate the sympathetic nervous system, which can adversely affect bone. We compared six groups of 10 young adult rats, three with and three without 2 h daily restraint stress. Two groups consumed food and water ad libitum, two received food and 6% (w/v) ethanol as drinking water, and two received the amount of food consumed by ethanol rats the previous day plus water ad libitum (pairfed). After 6 weeks, rats were killed. Plasma, femurs, lumbar vertebrae, and adrenals were harvested. Femoral dimensions were measured and biomechanical properties were tested by three-point bending. Plasma osteocalcin, vertebral osteocalcin mRNA levels, and adrenomedullary tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DBH), and phenylethanolamine N-methyl transferase (PNMT) mRNA levels were quantified. Daily restraint decreased weight gain and femoral length compared to dietary controls, and appeared to partially preserve bone strength, especially in calorie-restricted pairfed rats. Femoral strength was significantly affected by treatment in that bones of pairfed controls were weakest, ethanol drinkers were intermediate, and ad libitum restrained were strongest. Femoral yield load, displacement, and work at yield load were negatively correlated with TH and DBH mRNA levels, but not PNMT, suggesting a negative influence of norepinephrine. Plasma osteocalcin and dry weight of lumbar 3-5 vertebrae were unaffected; however, osteocalcin mRNA in second lumbar vertebrae was positively correlated with TH, DBH, and PNMT levels. Ethanol consumption at this level had little effect on femur morphology or strength. In contrast, the data suggested possible stimulation rather than inhibition of vertebral bone formation.

The Neurobiological Links between Stress and Traumatic Brain Injury: A Review of Research to Date

“…During RS, NE levels decrease in the hippocampus and cortex, which are associated with behavioral changes [ 200 ]. Several studies have reported increased NE in peripheral blood after stress [ 201 , 202 , 203 ]. Overall, NE shows the opposite expression in peripheral blood and the CNS, which may be related to its different origins.…”

Altered Ethanol Consumption in Osteocalcin Null Mutant Mice

“…They speculated that either the OC secretory pathway is inhibited by EtOH or that OC was degraded intracellularly due to the direct effect of EtOH on osteoblasts (Wezeman, Emanuele et al 1999). We determined that moderate EtOH (6%) consumption with or without the imposition of 6 weeks daily restraint in wire mesh cages had little effect on young adult rat femur morphology or strength or on plasma OC, but that calorie-restricted rats pairfed to the EtOH consuming group were negatively affected by restraint (Patterson-Buckendahl, Pohorecky et al 2008).…”