RESUMO
The correlation of primary stress indicator; melanophore index (MI) with set of genomic stress indicators is important for a better understanding of the cellular stress pathway induced by xenobiotics in aquatic species. This study presents a correlation between melanophore index (MI) and genomic stress indicators in Oreochromis mossambicus treated with lead nitrate, phenol and hexachlorocyclohexane (HCH). O. mossambicus was exposed to sub-lethal concentrations of the different LC50 values (96 h) of the tested chemicals at varying exposure periods and the response via genomic stress indicators and scale melanophores were assessed in accordance with standard protocols. Melanophore index decreased significantly (p<0.01) in a time dependent pattern to the tested chemicals. Gene expression showed significant time dependent increase in the expression of heat shock proteins (HSP70 and HSP60). Vitellogenin (Vtg) expression insignificantly altered. Significant increase in the expression of melanin concentrating hormone (MCH) was observed in response to hexachlorocyclohexane (HCH) in the treated fish. The findings demonstrated an inverse relationship between melanophore index and the set of genomic stress indicators.
Assuntos
Hexaclorocicloexano/toxicidade , Chumbo/toxicidade , Melanóforos/efeitos dos fármacos , Nitratos/toxicidade , Fenol/toxicidade , Tilápia/genética , Poluentes Químicos da Água/toxicidade , Animais , Chaperonina 60/genética , Ecossistema , Meio Ambiente , Proteínas de Peixes/genética , Expressão Gênica/efeitos dos fármacos , Genômica , Proteínas de Choque Térmico HSP70/genética , Hormônios Hipotalâmicos/genética , Dose Letal Mediana , Melaninas/genética , Hormônios Hipofisários/genética , Estresse Fisiológico , Vitelogeninas/genéticaRESUMO
Oxytocin (OT) plays an important role in social bonding, ultrasonic vocalizations and other sexual behaviors in mammalian species. Although its presence within neuroendocrine regions in the forebrain is well established, its association with sensory nuclei remains unclear. We report here the presence of oxytocin immunoreactive neurons within several nuclei in the auditory brain stem of the mustached bat, Pteronotus parnellii. Immunocytochemical procedures revealed OT-immunoreactive perikarya and/or fiber terminals in restricted areas of the inferior colliculus (IC), superior olivary complex (SOC), including the medial and ventral nuclei of the trapezoid body, and in the cochlear nucleus. Perikarya were labeled predominantly in the IC and SOC and both perikarya and fiber terminals were labeled extensively in the cochlear nucleus.