Galanin-like immunoreactivity in the brain and pituitary of the "four-eyed" fish, Anableps anableps.

The distribution of galanin (GAL)-like immunoreactivity was investigated in the brain and pituitary of the "four-eyed" fish, Anableps anableps. GAL-immunoreactive (GAL-ir) perikarya were located in the area ventralis telencephali pars supracommissuralis, nucleus preopticus periventricularis, nucleus preopticus pars parvocellularis, nucleus preopticus pars magnocellularis, nucleus lateralis tuberis ventralis, nucleus lateralis tuberis lateralis, and nucleus lateralis tuberis posterior. A few scattered, GAL-ir neurons were also observed in or adjacent to the nucleus recessus lateralis, nucleus recessus posterioris and lobus facialis (VII). GAL-ir fiber networks were widespread in the brain, with a comparatively higher density in the ventral telencephalic, preoptic and infundibular regions. The neurohypophysis showed GAL-ir innervation and there were GAL-ir cells in the adenohypophysis. The presence of GAL-ir cells in the hypothalamus and in the pituitary is an important asset for the supposed role of GAL-like peptide in neuroendocrine regulation of brain and pituitary functions.

NADPH-diaphorase expression in the hypothalamo-hypophysial system of different catfish.

The distribution of NADPH-d activity was studied in the hypothalamus and in the pituitary gland of 15 species of catfish. Seven hypothalamic nuclei, four fiber bundles, as well as cells located in the adenohypophysis were labeled by NADPH-d histochemistry. Reactive somata were found in the nucleus praeopticus periventricularis, the paraventricular division of the nucleus praeopticus, the supraoptic division of the nucleus praeopticus, the nucleus lateralis tuberis, the paraventricular organ, the nucleus recessus lateralis, the nucleus recessus posterioris, and in the adenohypophysis. In some species, an inconsistent number of these structures lacked NADPH-d activity. These results are compatible with the notion that NADPH-d activity expressing cells in the hypothalamus and in the pituitary are involved in the control of hormone regulation.

Effect of cadmium chloride on the pituitary, thyroid and gonads in the catfish, Clarias batrachus (Linn.).

The effect of cadmium chloride on the pituitary ACTH cells, gonadotropin- and thyrotropin-secreting cells, thyroid gland and gonads of the catfish, Clarias batrachus was investigated. Exposure to cadmium chloride caused a significant increase in the ACTH cell nuclear indices at day 7, 14 and 28, whereas the thyrotropin- and gonadotropin-secreting cells showed inactivation and accumulation of secretary products. The epithelial height of the thyroid follicles was also significantly reduced (P < 0.001) as compared to that of the untreated control fish. In experimental female fish, the gonosomatic index had undergone a significant reduction at all intervals studied (day 7, 14 and 28). However, in the male catfish a significant reduction in the gonosomatic index was observed only after exposure for 28 days. Ovarian maturation seems to have become arrested at perinucleolar stage and spermatogenesis at spermatocyte stage. The possible involvement of the hypothalamo-hypophyseal system in gonadal regression was discussed.