Interrenal stress responsiveness of marbled sole, Pleuronectes yokohamae, inhabiting Tokyo Bay.
The interrenal stress responsiveness of marbled sole (Pleuronectes yokohamae) captured in the interior (Tokyo) and at the mouth (the Uraga Strait; Uraga) of Tokyo Bay, in the coastal region of Onjuku (the eastern coastal region of Chiba prefecture; Pacific) and in Ishinomaki Bay (Ishinomaki) in Japan was investigated. That is, the effects of air-exposure on plasma cortisol and glucose levels in the fish from the four different regions, and the effect of in vitro ACTH treatment on cortisol release from the head kidney tissue of the fish held under resting conditions were examined. In this study, it was found that (i) there were no significant differences in plasma cortisol and glucose levels among the fish from the four different regions under resting conditions, (ii) each air-exposed fish increased plasma cortisol and glucose levels, (iii) the cortisol response in marbled sole inhabiting Tokyo Bay, in particular the interior, was lower, delayed and prolonged, and (iv) cortisol release from the head kidney to in vitro ACTH treatment was lower in the fish from Tokyo compared with the fish from the reference (not so polluted) sites, Pacific and Ishinomaki. These results suggest that marbled sole inhabiting Tokyo Bay, in particular the interior, have been altered in their responsiveness of cortisol-producing interrenal cells to the stressor in the hypothalamus-pituitary-interrenal (HPI) axis.
Kakuta
Izuru
I
Department of Biotechnology, Senshu University of Ishinomaki, Ishinomaki 986-8580, Japan. kakuta@isenshu-u.ac.jp
D000222:Adaptation, Physiological; D000388:Air; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D005432:Flounder / Q000502:physiology*; D006854:Hydrocortisone / Q000097:blood; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000502:physiology*; D007668:Kidney / Q000737:chemistry; D010913:Pituitary-Adrenal System / Q000187:drug effects / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000009:adverse effects*
D001786:Blood Glucose; D014874:Water Pollutants, Chemical; D006854:Hydrocortisone