Influence of age and splanchnic nerve on the action of melatonin in the adrenomedullary catecholamine content and blood glucose level in the avian group.
A single intraperitoneal (IP) melatonin injection (0.5 mg/100 g body wt.) caused an increase in norepinephrine (NE) fluorescence and elevation of NE content in newly-hatched pigeons (Columba livia), but a reduction of NE fluorescence and depletion of NE content in the adrenal medulla of newly-hatched crows (Corvus splendens) after 0.5 h of treatment. In contrast, in adults melatonin caused increase in NE fluorescence and elevation of NE content only in the parakeet (Psittacula krameri). Half an hour of IP melatonin treatment (0.5 mg/100 g body wt.) induced release of epinephrine (E) from the adrenal medulla of newly-hatched pigeon and parakeet. In contrast, in the adults melatonin caused more than a two-fold increase in E in the pigeon, and a significant increase in the crow. Single IP melatonin injection (0.5 mg/100 g body wt.) caused hypoglycemia in the newly-hatched parakeet and adult pigeon, and hyperglycemia in newly-hatched pigeon after 0.5 h of treatment. Melatonin failed to regulate glucose homoeostasis in newly-hatched and adult crow. Splanchnic denervation of the left adrenal gland was performed in the adult pigeon. The right adrenal served as the innervated gland. Melatonin-induced modulation of catecholamines following a single IP injection (0.5 mg/100 g body wt.) revealed significant increases in NE fluorescence and NE content at 4 and 12 h after treatment in the denervated gland only, which gradually approached normal levels 9 days after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Mahata
S K
SK
Department of Zoology, University of Calcutta, India.
Mandal
A
A
Ghosh
A
A
D000313:Adrenal Medulla / Q000032:analysis* / Q000378:metabolism; D000375:Aging / Q000502:physiology*; D000818:Animals; D001717:Birds / Q000502:physiology*; D001786:Blood Glucose / Q000032:analysis* / Q000378:metabolism; D002395:Catecholamines / Q000032:analysis* / Q000378:metabolism; D010856:Columbidae; D005260:Female; D006706:Homeostasis / Q000187:drug effects; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D008856:Microscopy, Fluorescence; D010240:Parakeets; D013050:Spectrometry, Fluorescence; D013153:Splanchnic Nerves / Q000502:physiology*
D001786:Blood Glucose; D002395:Catecholamines; D008550:Melatonin