L-cystine-di-beta-naphthylamidase activity in plasma of the snake Bothrops jararaca after chronic challenges of water balance.
Plasma protein, osmolality and L-cystine-di-beta-naphthylamidase activity were measured in Bothrops jararaca snakes submitted to normal hydration, water deprivation, water loading, salt loading or argvasotocin injections. Protein and osmolality were similar for male and female snakes in all treatments. Protein content was similar in all treatments, indicating the ability of the animals to maintain fluid balance between the vascular and extravascular compartment under osmotic challenges. Osmolality was increased in water-deprived and salt-loaded and was decreased in water-loaded animals compared with normally hydrated or argvasotocin-injected snakes. Enzymatic activity differed between males and females and was higher in salt-loaded females and in arg-vasotocin-injected females and males than in water-loaded snakes. A positive linear regression between osmolality and L-cystine-di-beta-naphthylamidase was obtained for female snakes (correlation coefficient = 0.6162, P < 0.01). The data show a role of arg-vasotocin in the consistent relationship between water balance and this sex-related aminopeptidase activity.
Silveira
P F
PF
Department of Physiology, Universidade de São Paulo, Brazil.
Mimura
O M
OM
D000626:Aminopeptidases / Q000097:blood*; D000818:Animals; D001835:Body Weight / Q000502:physiology; D017837:Bothrops / Q000378:metabolism*; D003553:Cystine / Q000378:metabolism*; D003681:Dehydration / Q000378:metabolism; D005260:Female; D008297:Male; D012727:Sex Characteristics; D012965:Sodium Chloride / Q000494:pharmacology; D015996:Survival Rate; D014668:Vasotocin / Q000378:metabolism; D014868:Water Deprivation / Q000502:physiology; D014882:Water-Electrolyte Balance / Q000502:physiology; D014883:Water-Electrolyte Imbalance / Q000097:blood*
D012965:Sodium Chloride; D003553:Cystine; D000626:Aminopeptidases; D014668:Vasotocin