Immunocytochemical distribution of corticotropin-releasing factor in the brain and hypophysis of larval Bufo arenarum; effect of KClO4 during early development

Immunoidentification of CRF-like material in the intermaxillary glands during Bufo arenarum development

“…The presence of mammalian CRF-like immunoreactivity has been identified in hypothalamus of both urodeles and anurans (Olivereau et al, 1984;Fasolo, 1984;Tonon et al, 1986;Gonzalez & Lederis, 1988). In larvae of Rana catesbeiana (Carr & Norris, 1990) and B. arenarum (Miranda & Dezi, 1997) it was observed that CRF-like material in the median eminence increased during prometamorphosis, and became most dense at metamorphic climax, indicating that the CRF-like neuronal system develops just before the elevation of corticoid and thyroids hormones.…”

“…Corticotropin-releasing factor (CRF) is a 41-amino acid peptide initially isolated from the ovine hypothalamus (Spiess et al, 1981) as a result of its ability to stimulate the secretion of corticotropin (ACTH) by anterior pituitary cells (Vale et al, 1981). The presence of mammalian CRF-like immunoreactivity has been observed in hypothalamus of both urodeles and anurans (Olivereau et al, 1984;Fasolo, 1984;Tonon et al, 1986;Gonzalez & Lederis, 1988;Carr & Norris, 1990;Miranda & Dezi, 1997). In the last few years, it has been demonstrated that CRF (Denver, 1988;1993;Denver & Licht, 1989;Jacobs & Kühn, 1989;Malagón et al, 1991;Gancedo et al, 1992;Miranda et al, 1999) and CRF-like peptide sauvagine (SV) (Denver 1993; accelerate amphibian metamorphosis stimulating thyroid axis.…”

Expression profiles of metamorphosis-related genes during natural transformations in tadpoles of wild Wood Frogs (Lithobates sylvaticus)

“…In NF52-NF54 X. laevis tadpoles, exogenous T3 was shown to up-regulate crf gene expression levels (Denver 1997). Studies using immunocytochemistry for the CRF peptide indicate that CRF production tends to increase, peaking at metamorphic climax in several anuran species (Miranda and Dezi 1997;Matsuda et al 2010), although this is highly dependent on the brain region examined. Boorse and Denver (2003) found that water volume reduction did not alter CRF peptide contents in the forebrain-midbrain regions during metamorphosis of Western Spadefoot Toads Fig.…”