Cholinergic and adrenergic innervation of lingual salt glands of the estuarine crocodile, Crocodylus porosus
Craig E. Franklin A B , Greg Taylor A and Rebecca L. Cramp AA School of Integrative Biology, The University of Queensland, Brisbane, Qld 4072, Australia.
B Corresponding author. Email: c.franklin@uq.edu.au
Australian Journal of Zoology 53(6) 345-351 https://doi.org/10.1071/ZO05001
Submitted: 10 January 2005 Accepted: 19 October 2005 Published: 6 January 2006
Abstract
Many marine reptiles and birds possess extrarenal salt glands that facilitate the excretion of excess sodium and chloride ions accumulated as a consequence of living in saline environments. Control of the secretory activity of avian salt glands is under neural control, but little information is available on the control of reptilian salt glands. Innervation of the lingual salt glands of the salt water crocodile, Crocodylus porosus, was examined in salt water-acclimated animals using histological methods. Extensive networks of both cholinergic and adrenergic nerve fibres were identified close to salt-secreting lobules and vasculature. The identification of both catecholamine-containing and cholinergic neurons in the salt gland epithelium and close to major blood vessels in the tissue suggests the action of the neurotransmitters on the salt-secreting epithelium itself and the rich vascular network of the lingual salt glands.
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