Arginine vasotocin: locus of action along the nephron of the ornate dragon lizard, Ctenophorus ornatus.
The first measurements of AVT-sensitive adenylate cyclase activity in specific segments of the nephron of the Australian arid-zone agamid lizard, Ctenophorus (=Amphibolurus) ornatus, are reported. All sections of the collecting-duct system of this lizard were found to be sensitive to AVT at a concentration of 1 x 10(-6) M. In addition, receptors to AVT were located in the thin-intermediate segment linking proximal and distal convoluted tubules. No significant response to AVT was detected in the glomeruli, in either proximal or distal convoluted tubules, or in the ureter. The physiological significance of these particular segments is discussed in terms of the action of AVT in stimulating water and salt reabsorption in the lizard kidney.
Bradshaw
F J
FJ
Department of Zoology and Centre for Native Animal Research, University of Western Australia, Perth, Western Australia, 6907, Australia.
Bradshaw
S D
SD
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000096:biosynthesis; D005260:Female; D005615:Freezing; D008116:Lizards / Q000502:physiology*; D008297:Male; D009399:Nephrons / Q000033:anatomy & histology / Q000187:drug effects* / Q000378:metabolism; D009997:Osmotic Pressure; D012680:Sensitivity and Specificity; D012969:Sodium Fluoride / Q000494:pharmacology; D014668:Vasotocin / Q000494:pharmacology*
D005576:Colforsin; D012969:Sodium Fluoride; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D014668:Vasotocin