GnRH-LH secreting cells axis in the pituitary of the teleost Clarias batrachus responds to neuropeptide Y treatment: an immunocytochemical study

Reproduction phase‐related variations in neuropeptide Y immunoreactivity in the olfactory system, forebrain, and pituitary of the female catfish, Clarias batrachus (Linn.)

“…DOI 10.1002/cne sera against human LH-␤ fraction labeled gonadotropic cells in the pituitary of seabass (Moons et al, 1989), Atlantic croaker, spotted seatrout, and red sea drum (Yan and Thomas, 1991). The antisera also labeled a population of cells in the PPD of C. batrachus in the present study as well as in our earlier studies (Gaikwad et al, 2003;Mazumdar et al, 2006). Furthermore, Siegmund et al (1987) observed that the immunodeterminants of the ␤-subunit of gonadotropic hormone might be highly conserved through the phylogeny.…”

“…In our earlier studies on the same fish, we employed similar antisera against NPY (N 9528; Sigma) and human LH-␤ (NHPP, NIH) to localize the NPY and LH immunoreactivity in the brain and pituitary, respectively (Gaikwad et al, 2003(Gaikwad et al, , 2004Mazumdar et al, 2006). Specificity of these antisera was confirmed in this study also.…”

“…Reddish-brown precipitate indicated the presence of antigen in the section. Similarly, the rabbit antisera against human LH-␤ (lot AFP55951880; generous gift of Dr. Parlow, NHPP, NIH) was employed to localize the LHimmunoreactive cells in the pituitary of C. batrachus as described earlier (Gaikwad et al, 2003;Mazumdar et al, 2006). The immunogen for developing the rabbit antiserum was human pituitary LH-␤, which was highly purified by selective immunoaffinity purification (SIAFP) in the laboratory of Dr. Parlow, NHPP, UCLA Medical Center, which denuded the human LH-␤ of all contamination with other pituitary hormones.…”

“…The annual sexual cycle of the catfish C. batrachus is tightly linked to the seasons and is divisible into five distinct phases: 1) resting phase (December-January), 2) preparatory phase (February-April), 3) prespawning phase (MayJune), 4) spawning phase (July-August), and 5) postspawning phase (September-November). In view of the available background information on the distribution of GnRH (Subhedar and Rama Krishna, 1988) and the neuroanatomical organization of NPY-containing system and its involvement in the regulation of GnRH and GnRH-LH cell axis (Gaikwad et al, 2003(Gaikwad et al, , 2005 in C. batrachus, this fish served a suitable model for the present study. We investigated the reproductive phase-related changes in NPY immunoreactivity in the olfactory system, forebrain, and pituitary of C. batrachus.…”

Neuropeptide Y in the forebrain of the adult male cichlid fish Oreochromis mossambicus: Distribution, effects of castration and testosterone replacement

“…The areas (in square micrometers) occupied by the NPY-ir fibers per unit field measuring 21,389 m 2 were estimated from the transverse sections passing through the olfactory bulb (OB), telencephalon, preoptic area, hypothalamus, and inferior lobes of initial control, sham-castrated, castrated and testosterone-replaced fish. The method has already been standardized in our laboratory (Gaikwad et al, 2003). The images of NPY-ir fibers were digitized, the background was considered as the threshold, and the areas occupied by the immunoreactive fibers were measured based on individual pixel intensity as described by Tai et al (1997).…”