S. D. McCormick J. M. Mancera 1999 <p>The capacity of cortisol, ovine growth hormone (oGH), recombinant bovine insulin-like growth factor I (rbIGF-I) and 3,3′,5-triiodo-l-thyronine (T₃) to increase hypoosmoregulatory capacity in the euryhaline teleost Fundulus heteroclitus was examined. Fish acclimated to brackish water (BW, 10&nbsp;ppt salinity) were injected with a single dose of hormone suspended in oil and transferred to seawater (SW, 35&nbsp;ppt salinity) 10 days post-injection. Fish were sampled 24&nbsp;h after transfer and plasma osmolality and gill Na⁺, K⁺-ATPase activity were examined. Transfer from BW to SW induced significantly increased plasma osmolality but not gill Na⁺, K⁺-ATPase activity. Cortisol (50&nbsp;μg&nbsp;g⁻¹&nbsp;body weight) improved the ability to maintain plasma osmolality and to increase gill Na⁺, K⁺-ATPase activity. oGH (5&nbsp;μg&nbsp;g⁻¹&nbsp;body weight) also increased hypoosmoregulatory ability and gill Na⁺, K⁺-ATPase activity. A cooperation between oGH and cortisol was observed in increasing hypoosmoregulatory ability but not in increasing gill Na⁺, K⁺-ATPase activity. rbIGF-I (0.5&nbsp;μg&nbsp;g⁻¹&nbsp;body weight) alone was without effect in increasing salinity tolerance or gill Na⁺, K⁺-ATPase activity. rbIGF-I and oGH showed a positive interaction in increasing salinity tolerance, but not gill Na⁺, K⁺-ATPase activity. Treatment with T₃&nbsp;(5&nbsp;μg&nbsp;g⁻¹&nbsp;body weight) alone did not increase salinity tolerance or gill Na⁺, K⁺-ATPase activity, and there was no consistent significant interaction between cortisol and T₃&nbsp;or between GH and T₃. The results confirm the classical role of cortisol as a seawater-adapting hormone and indicate an interaction between cortisol and the GH/IGF-I axis during seawater acclimation of Fundulus heteroclitus.<br data-mce-bogus="1"></p> application/pdf 10.1023/A:1007737924339 en Springer Link Influence of cortisol, growth hormone, insulin-like growth factor I and 3,3′,5-triiodo-l-thyronine on hypoosmoregulatory ability in the euryhaline teleost Fundulus heteroclitus article