Abstract
We recently discovered novel cDNAs encoding the precursors of two small secretory proteins, neurosecretory protein GL (NPGL) and neurosecretory protein GM (NPGM), in the mediobasal hypothalamus (MBH) of chickens. In addition, we found colocalization of NPGL, NPGM, and histidine decarboxylase (HDC; histamine-producing enzyme) in same neurons of the medial mammillary nucleus of the hypothalamus. In this study, we elucidated the effect of several stresses, including food deprivation, environmental heat, inflammation, and social isolation, on the mRNA expression of NPGL, NPGM, and HDC in chicks using real-time PCR. Food deprivation for 24 h increased NPGM mRNA expression in the MBH. On the other hand, an environmental temperature of 37°C for 24 h did not affect their mRNA expression. Six hours after intraperitoneal injection of lipopolysaccharide, an inducer of inflammation, the mRNA expression of NPGM, but not that of NPGL and HDC increased. Social isolation for 3 h induced an increase in the mRNA expression of NPGL, NPGM, and HDC. These results indicate that NPGM, but not NPGL or HDC, may participate in several physiological responses to stress in chicks.
Highlights
Biological stress responses are induced through the hypothalamus, which is known as the central region of the autonomic nervous system and endocrine system
To investigate the effect of ambient temperature, we examined the mRNA expression of neurosecretory protein GL (NPGL), neurosecretory protein GM (NPGM), and histidine decarboxylase (HDC) under heat stress
The results of the stress experiments suggested that the changes in the mRNA expressions of NPGL, NPGM, and HDC depend on the type of stressor
Summary
Biological stress responses are induced through the hypothalamus, which is known as the central region of the autonomic nervous system and endocrine system. Exposure to stress induces the hypothalamus to secrete neuropeptides, corticotropin-releasing factor (CRF), and arginine vasotocin (AVT) in the paraventricular nuclei (PVN); and stimulates the pituitary gland to release adrenocorticotropic hormone (ACTH; Barth and Grossmann, 2000; Jenkins and Porter, 2004). ACTH, secreted by the pituitary gland, stimulates the adrenal cortex through the bloodstream causing the synthesis and secretion of adrenal cortex hormones. Corticosterone is another biological marker of stress in birds (Dmitriev et al, 2001; Feltenstein et al, 2003; Pereyra and Wingfield, 2003). As chickens are one of the most important food resources, research on stress responses affecting egg and meat production is important
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
