Salinity adaptation in fish: effect of thyroxine on mitochondrial status.
Upon transfer of the fresh-water fish, Sarotherodon mossambicus, to 50% sea water, extensive changes take place in the functions of the gill mitochondria. The changes are (i) loss of ADP/O and RCI; (ii) loss of the ability to contract upon addition of ATP-Mg2+; (iii) lowered energy-dependent 45Ca uptake; (iv) increased amino acid incorporation capacity; (v) increased adenine nucleotide content; and (vi) a higher endogenous Ca2+ content. Administration of thyroxine to the fish reversed these changes, and the effect of thyroxine was also not transient. It is suggested that thyroxine promotes mitochondriogenesis, thereby effecting a restoration of the stress-affected mitochondrial functions.
D000222:Adaptation, Physiological / Q000187:drug effects; D000818:Animals; D005399:Fishes / Q000502:physiology*; D005880:Gills / Q000502:physiology; D008928:Mitochondria / Q000502:physiology*; D011863:Radioimmunoassay; D012623:Seawater; D012965:Sodium Chloride; D013312:Stress, Physiological / Q000503:physiopathology; D013890:Thiourea / Q000494:pharmacology; D013974:Thyroxine / Q000097:blood / Q000502:physiology*
D012965:Sodium Chloride; D013890:Thiourea; D013974:Thyroxine