Carbaryl exposure and recovery modify the interrenal and thyroidal activities and the mitochondria-rich cell function in the climbing perch Anabas testudineus Bloch.

We examined the effects of carbaryl (1-naphthyl methylcarbamate; sevin), a carbamate pesticide, on interrenal and thyroid activities and mitochondrial rich (MR) cell function in climbing perch to understand the physiological basis of toxicity acclimation in this fish to the chemical stressor. Carbaryl exposure (5-20 mg L(-1)) for 48 h increased cortisol and glucose, but decreased the T(3) level without affecting T(4) concentration in the plasma. These responses of the carbaryl-exposed fish were nullified and a rise in plasma T(4) occurred in these fish when they were kept for 96 h recovery in clean water.

Cortisol promotes and integrates the osmotic competence of the organs in North African catfish (Clarias gariepinus Burchell): Evidence from in vivo and in situ approaches.

The short-term in situ and long-term in vivo effects of cortisol were examined in North African catfish (Clarias gariepinus) to identify how this major corticosteroid integrates the osmotic competence of fish organs. In the in situ approach, the hydromineral effects of cortisol perfusion (75-300 ng ml(-1)) for 20 min were tested and the indices of hydromineral and metabolic regulations were measured in our in vivo experimental fish after three alternate intraperitoneal cortisol injections (40 and 200 ng g(-1) body mass) for 5 days. Na(+), K(+)-ATPase activity, a measure of cellular osmotic competence, responded to in situ and in vivo cortisol treatments.