Effects of ethanol on plasma ghrelin levels in the rat during early and late adolescence

Alcohol. 2020 Jun;85:111-118. doi: 10.1016/j.alcohol.2019.12.006. Epub 2020 Jan 7.

Abstract

Ghrelin is an appetite-regulating peptide that is primarily secreted by endocrine cells in the stomach and is implicated in regulation of alcohol consumption and alcohol-reinforced behaviors. In the present study, adolescent Sprague-Dawley rats received intermittent ethanol (AIE) exposure by intragastric intubation (5 g/kg) or vapor inhalation, manipulations conducted between postnatal days (PD) 28-43. On the first and last day of AIE exposure, the level of intoxication was examined 1 h after ethanol gavage or upon removal from the vapor chamber. This was immediately followed by a blood draw for determination of the blood ethanol concentration (BEC) and plasma levels of acylated ghrelin (acyl-ghrelin; active). On PD29, plasma levels of acyl-ghrelin were significantly elevated in male (but not female) rats in response to acute ethanol exposure by both gastric gavage and vapor inhalation. Importantly, assessment of plasma acyl-ghrelin in response to repeated ethanol exposure revealed a complex interaction of both sex and method of AIE exposure. On PD43, vapor inhalation increased plasma acyl-ghrelin in both males and females compared to their air-control counterparts, whereas there was no change in plasma levels of acyl-ghrelin in either male or female rats in response to exposure by intragastric gavage. Assessment of plasma acyl-ghrelin following a 30-day ethanol-free period revealed AIE exposure did not produce a change in basal levels. In addition, an acute ethanol challenge in adult rats of 5 g/kg via gastric gavage had no effect on plasma ghrelin levels when assessed 1 h after initiation of exposure. Collectively, these observations suggest that acyl-ghrelin, a primary gut-brain signaling hormone, is elevated by ethanol during early adolescence independent of administration route, and in gender-dependent fashion.

Keywords: Adolescence; Alcohol; Ethanol vapor; Ghrelin; Intragastric ethanol; intermittent ethanol.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Administration, Inhalation
  • Animals
  • Ethanol / administration & dosage
  • Ethanol / blood
  • Ethanol / pharmacology*
  • Female
  • Ghrelin / analogs & derivatives*
  • Ghrelin / blood
  • Intubation, Gastrointestinal
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Sex Characteristics

Substances

  • Ghrelin
  • acyl-ghrelin
  • Ethanol