Salt gland blood flow in the hatchling green turtle, Chelonia mydas

J Comp Physiol B. 2000 Dec;170(8):573-80. doi: 10.1007/s003600000136.

Abstract

Microsphere and morphometric techniques were used to investigate any circulatory changes that accompany secretion by the salt glands of hatchling Chelonia mydas. Salt glands were activated by a salt load of 27.0 mmol NaCl x kg body mass (BM)(-1), resulting in a mean sodium secretion rate of 4.14 +/- 0.11 mmol Na x kg BM(-1) x h(-1) for a single gland. Microsphere entrapment was approximately 160-180 times greater in the active salt gland than the inactive gland, inferring a similar change in blood flow through salt gland capillaries. The concentration of microspheres trapped in the salt gland was significantly correlated with the rate of tear production (ml x kg BM(-1) x h(-1)) and the total rate of sodium secretion (mmol Na x kg BM(-1) x h(-1)) but not with tear sodium concentration (mmol Na x l(-1)). Adrenaline (500 microg x kg BM(-1)) inhibited tear production within 2 min and reduced microsphere entrapment by approximately 95% compared with active glands. The volume of filled blood vessels increased from 0.03 +/- 0.01% of secretory lobe volume in inactive salt gland sections to 0.70 +/- 0.11% in active gland sections. The results demonstrate that capillary blood flow in the salt gland of C. mydas can regulate the activity of the gland as a whole.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Capillaries / physiology
  • Epinephrine / pharmacology
  • Microspheres
  • Regional Blood Flow
  • Salt Gland / blood supply*
  • Salt Gland / cytology
  • Salt Gland / drug effects
  • Salt Gland / metabolism*
  • Sodium / metabolism*
  • Sodium Chloride / administration & dosage
  • Tears / metabolism
  • Turtles / anatomy & histology
  • Turtles / physiology*

Substances

  • Sodium Chloride
  • Sodium
  • Epinephrine