Effect of melatonin administration and long day-length on endocrine cycles in the hedgehog Erinaceus europaeus

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The effects of exogenous melatonin (subcutaneous implants containing 0.031 0.006 mg/gm body mass melatonin) or long photoperiod (18L:6D) on wild-caught adult male hedgehogs were studied. Hedgehogs were implanted with melatonin-filled or empty capsules in May, August, or September, or maintained under long photoperiod from August. Blood samples collected at monthly intervals were assayed for testosterone, melatonin, and thyroxin. Melatonin-filled capsules elevated plasma melatonin concentrations for 4-6 months. Although melatonin administration in May depressed plasma testosterone levels, testicular reactivation was advanced by 1 month the following year, and the characteristic prehibernal gain in body mass was abolished. Melatonin administration in August had no effect on plasma testosterone concentrations but reduced body mass fluctuations before and during hibernation. Hedgehogs receiving melatonin in September recovered early from hibernal body mass loss and showed a 2 month advance in testicular reactivation the following year. Maintaining hedgehogs at 18L:6D photoperiod, however, elevated plasma melatonin concentrations. Testicular reactivation the following spring was delayed by 1 month, ended 3 months early, and testosterone concentrations were depressed. All treatments depressed plasma thyroxin levels. These results suggest that elevated melatonin levels during winter are important in the regulation of endogenous endocrine cycles in the hedgehog. Hedgehogs do not respond positively to melatonin at the end of the breeding season, but are again responsive to melatonin as early as September.

Original languageEnglish
Pages (from-to)67-78
Number of pages12
JournalJournal of Pineal Research
Volume8
Issue number1
DOIs
Publication statusPublished - 1990

Keywords

  • animals
  • body weight
  • body weight drug effects
  • hedgehogs
  • hedgehogs physiology
  • light
  • male
  • melatonin
  • melatonin blood
  • melatonin pharmacology
  • periodicity
  • seasons
  • testosterone
  • testosterone blood
  • thyroxine
  • thyroxine blood

Cite this

@article{2b438b2156ee411ba3d345351d7860b0,
title = "Effect of melatonin administration and long day-length on endocrine cycles in the hedgehog Erinaceus europaeus",
abstract = "The effects of exogenous melatonin (subcutaneous implants containing 0.031 0.006 mg/gm body mass melatonin) or long photoperiod (18L:6D) on wild-caught adult male hedgehogs were studied. Hedgehogs were implanted with melatonin-filled or empty capsules in May, August, or September, or maintained under long photoperiod from August. Blood samples collected at monthly intervals were assayed for testosterone, melatonin, and thyroxin. Melatonin-filled capsules elevated plasma melatonin concentrations for 4-6 months. Although melatonin administration in May depressed plasma testosterone levels, testicular reactivation was advanced by 1 month the following year, and the characteristic prehibernal gain in body mass was abolished. Melatonin administration in August had no effect on plasma testosterone concentrations but reduced body mass fluctuations before and during hibernation. Hedgehogs receiving melatonin in September recovered early from hibernal body mass loss and showed a 2 month advance in testicular reactivation the following year. Maintaining hedgehogs at 18L:6D photoperiod, however, elevated plasma melatonin concentrations. Testicular reactivation the following spring was delayed by 1 month, ended 3 months early, and testosterone concentrations were depressed. All treatments depressed plasma thyroxin levels. These results suggest that elevated melatonin levels during winter are important in the regulation of endogenous endocrine cycles in the hedgehog. Hedgehogs do not respond positively to melatonin at the end of the breeding season, but are again responsive to melatonin as early as September.",
keywords = "animals , body weight, body weight drug effects, hedgehogs, hedgehogs physiology, light, male, melatonin, melatonin blood, melatonin pharmacology, periodicity, seasons, testosterone, testosterone blood, thyroxine, thyroxine blood",
author = "Fowler, {Paul Alfred Francois} and Paul Racey",
year = "1990",
doi = "10.1111/j.1600-079X.1990.tb00808.x",
language = "English",
volume = "8",
pages = "67--78",
journal = "Journal of Pineal Research",
issn = "0742-3098",
publisher = "Wiley-Blackwell",
number = "1",

}

TY - JOUR

T1 - Effect of melatonin administration and long day-length on endocrine cycles in the hedgehog Erinaceus europaeus

AU - Fowler, Paul Alfred Francois

AU - Racey, Paul

PY - 1990

Y1 - 1990

N2 - The effects of exogenous melatonin (subcutaneous implants containing 0.031 0.006 mg/gm body mass melatonin) or long photoperiod (18L:6D) on wild-caught adult male hedgehogs were studied. Hedgehogs were implanted with melatonin-filled or empty capsules in May, August, or September, or maintained under long photoperiod from August. Blood samples collected at monthly intervals were assayed for testosterone, melatonin, and thyroxin. Melatonin-filled capsules elevated plasma melatonin concentrations for 4-6 months. Although melatonin administration in May depressed plasma testosterone levels, testicular reactivation was advanced by 1 month the following year, and the characteristic prehibernal gain in body mass was abolished. Melatonin administration in August had no effect on plasma testosterone concentrations but reduced body mass fluctuations before and during hibernation. Hedgehogs receiving melatonin in September recovered early from hibernal body mass loss and showed a 2 month advance in testicular reactivation the following year. Maintaining hedgehogs at 18L:6D photoperiod, however, elevated plasma melatonin concentrations. Testicular reactivation the following spring was delayed by 1 month, ended 3 months early, and testosterone concentrations were depressed. All treatments depressed plasma thyroxin levels. These results suggest that elevated melatonin levels during winter are important in the regulation of endogenous endocrine cycles in the hedgehog. Hedgehogs do not respond positively to melatonin at the end of the breeding season, but are again responsive to melatonin as early as September.

AB - The effects of exogenous melatonin (subcutaneous implants containing 0.031 0.006 mg/gm body mass melatonin) or long photoperiod (18L:6D) on wild-caught adult male hedgehogs were studied. Hedgehogs were implanted with melatonin-filled or empty capsules in May, August, or September, or maintained under long photoperiod from August. Blood samples collected at monthly intervals were assayed for testosterone, melatonin, and thyroxin. Melatonin-filled capsules elevated plasma melatonin concentrations for 4-6 months. Although melatonin administration in May depressed plasma testosterone levels, testicular reactivation was advanced by 1 month the following year, and the characteristic prehibernal gain in body mass was abolished. Melatonin administration in August had no effect on plasma testosterone concentrations but reduced body mass fluctuations before and during hibernation. Hedgehogs receiving melatonin in September recovered early from hibernal body mass loss and showed a 2 month advance in testicular reactivation the following year. Maintaining hedgehogs at 18L:6D photoperiod, however, elevated plasma melatonin concentrations. Testicular reactivation the following spring was delayed by 1 month, ended 3 months early, and testosterone concentrations were depressed. All treatments depressed plasma thyroxin levels. These results suggest that elevated melatonin levels during winter are important in the regulation of endogenous endocrine cycles in the hedgehog. Hedgehogs do not respond positively to melatonin at the end of the breeding season, but are again responsive to melatonin as early as September.

KW - animals

KW - body weight

KW - body weight drug effects

KW - hedgehogs

KW - hedgehogs physiology

KW - light

KW - male

KW - melatonin

KW - melatonin blood

KW - melatonin pharmacology

KW - periodicity

KW - seasons

KW - testosterone

KW - testosterone blood

KW - thyroxine

KW - thyroxine blood

U2 - 10.1111/j.1600-079X.1990.tb00808.x

DO - 10.1111/j.1600-079X.1990.tb00808.x

M3 - Article

VL - 8

SP - 67

EP - 78

JO - Journal of Pineal Research

JF - Journal of Pineal Research

SN - 0742-3098

IS - 1

ER -