The hypothalamo-hypophyseal system of the white seabream Diplodus sargus: immunocytochemical identification of arginine-vasotocin, isotocin, melanin-concentrating hormone and corticotropin-releasing factor.
The distribution of the neurosecretory hormones vasotocin, isotocin and melanin-concentrating hormone and the hypophysiotropic hormone corticotropin-releasing factor was studied in the hypothalamo-hypophyseal system of the white seabream (Diplodus sargus) using immunocytochemical techniques. Magnocellular and parvocellular perikarya immunoreactive for arginine-vasotocin and isotocin were present in the nucleus preopticus. Perikarya immunoreactive for arginine-vasotocin extended more caudally with respect to isotocin-immunoreactive perikarya. Parvocellular perikarya were located at rostroventral levels and magnocellular perikarya in the dorsocaudal portion of the nucleus. Arginine-vasotocin and isotocin did not coexist in the same neuron. Fibres immunoreactive for arginine-vasotocin and isotocin innervated all areas of neurohypophysis and terminate close to corticotropic and melanotropic cells. Perikarya immunoreactive for melanin-concentrating hormone and corticotropin-releasing factor were observed in the nucleus lateralis tuberis, with a few neurons in the nucleus periventricularis posterior. In addition, melanin-concentrating hormone immunoreactive perikarya were detected in the nucleus recessus lateralis. The preoptic nucleus did not show immunoreactivity for these antisera. Fibres showing melanin-concentrating hormone and corticotropin-releasing factor immunoreactivity ended close to the melanotropic and somatolactotrophic cells of the pars intermedia, and close to the corticotrophic cells of the rostral pars distalis.
Duarte
G
G
Departamento de Biología Animal, Facultad de Ciencias del Mar, Universidad de Cádiz, Spain.
Segura-Noguera
M M
MM
Martín del Río
M P
MP
Mancera
J M
JM
D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000032:analysis*; D007030:Hypothalamo-Hypophyseal System / Q000737:chemistry* / Q000166:cytology; D009474:Neurons / Q000737:chemistry / Q000166:cytology; D010121:Oxytocin / Q000031:analogs & derivatives / Q000032:analysis*; D010473:Perciformes; D010909:Pituitary Hormones, Posterior / Q000032:analysis; D014668:Vasotocin / Q000032:analysis*
D010909:Pituitary Hormones, Posterior; D010121:Oxytocin; D003346:Corticotropin-Releasing Hormone; D014668:Vasotocin