TY - JOUR
T1 - Plasma and brain angiotensin concentrations associated with water response behavior in the desert anuran, Scaphiopus couchii under natural conditions in the field
AU - Johnson, William E.
AU - Hillyard, Stanley D.
AU - Propper, Catherine R.
N1 - Funding Information:
We would like to thank Loretta Mayer, Randy Wade, and Lisa Rania for laboratory assistance and animal collection help. We would like to especially thank the staff at the Buenos Aires National Wildlife Refuge for our housing, collecting permits, and general assistance. This study was supported by NSF grant IBN 93-10352 to CRP and SDH.
PY - 2010/12
Y1 - 2010/12
N2 - Terrestrial amphibians obtain water by absorption across a specialized region of the ventral skin and exhibit a behavior, the water absorption response (WR) to place that region in contact with moist surfaces. Spadefoot toads (Scaphiopus couchii) spend dry months of the year in burrows, then emerge during brief periods of summer rainfall and seek water sources for rehydration and reproduction. We tested the hypothesis that these toads have changes in plasma and/or central angiotensin concentrations that are associated with seasonal emergence and WR behavior. Immunoreactive concentrations of combined angiotensin II and III (ir-ANG) were measured in plasma samples and microdissected regions of brain tissue taken from toads moving across the road or toads showing WR behavior in shallow puddles on the road. Plasma ir-ANG concentrations were not significantly different between these groups, but were significantly higher in the periventricular region of the hypothalamus in toads showing WR behavior. Concentrations in other brain regions, while highly variable among individuals, were not different between groups. Within the context of the natural history of a specialized desert toad, these results support the hypothesis that ir-ANG is associated with WR behavior in spadefoot toads in a manner analogous to oral drinking exhibited by other vertebrate clades.
AB - Terrestrial amphibians obtain water by absorption across a specialized region of the ventral skin and exhibit a behavior, the water absorption response (WR) to place that region in contact with moist surfaces. Spadefoot toads (Scaphiopus couchii) spend dry months of the year in burrows, then emerge during brief periods of summer rainfall and seek water sources for rehydration and reproduction. We tested the hypothesis that these toads have changes in plasma and/or central angiotensin concentrations that are associated with seasonal emergence and WR behavior. Immunoreactive concentrations of combined angiotensin II and III (ir-ANG) were measured in plasma samples and microdissected regions of brain tissue taken from toads moving across the road or toads showing WR behavior in shallow puddles on the road. Plasma ir-ANG concentrations were not significantly different between these groups, but were significantly higher in the periventricular region of the hypothalamus in toads showing WR behavior. Concentrations in other brain regions, while highly variable among individuals, were not different between groups. Within the context of the natural history of a specialized desert toad, these results support the hypothesis that ir-ANG is associated with WR behavior in spadefoot toads in a manner analogous to oral drinking exhibited by other vertebrate clades.
KW - Amphibian
KW - Angiotensin
KW - Anura
KW - Hypothalamus
KW - Thirst
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U2 - 10.1016/j.cbpa.2010.08.009
DO - 10.1016/j.cbpa.2010.08.009
M3 - Article
C2 - 20708705
AN - SCOPUS:77957264187
SN - 1095-6433
VL - 157
SP - 377
EP - 381
JO - Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology
JF - Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology
IS - 4
ER -