Correlation between spontaneous feeding behavior and neuropeptide Y profile in the third ventricular cerebrospinal fluid of goats

Feeding behavior is regulated by neural signals in the hypothalamus, but secretory activities of these signals in vivo and their relationship with spontaneous feeding remain to be solved. In the present study, we investigated the correlation between neuropeptide Y (NPY) and somatostatin (SRIF) profiles in cerebrospinal fluid (CSF) and spontaneous feeding behavior in goats. CSF samples were collected every 15 min for 8 h from the third ventricle and feeding behavior was observed throughout the experimental period. The spontaneous feeding behavior, the mean duration of which was 58 min, occurred with an interval of 146 min. NPY in the CSF fluctuated in an episodic fashion with a 145 min interval. Each NPY episode was followed by spontaneous feeding with a time lag of 24 min. SRIF levels in CSF changed more frequently in a pulsatile manner and were related to neither NPY profiles nor feeding behavior. These results suggest that NPY, but not SRIF, is a physiological signal to drive feeding in goats.     

Unveiling a voluntary farmland registration program to secure open space for risk reduction and post-disaster restoration from earthquakes: lessons learned from practices in Chukyo and Kinki,Japan

Paddy and Water Environment - Because of rapid urbanization, urban agriculture’s capacity to reduce the risks associated with natural disasters has been receiving broad attention. Asian...     

Production of a transgenic pig expressing human albumin and enhanced green fluorescent protein

We introduced a fusion gene of human albumin and enhanced green fluorescent protein (EGFP) into porcine oocytes using the sperm vector method, and produced a piglet that showed clear expression of GFP in the hooves and skin. PCR and Southern blotting analysis of genomic DNA extracted from the piglet's tissues, including the liver, showed that the tissues carried the transgene. RT-PCR analysis demonstrated that both the human albumin and EGFP genes were expressed in the tissues. The fact that human albumin gene was integrated and expressed in the liver of the transgenic pig opened a way for us to achieve our goal, which was the use of transgenic pigs for the bioartificial liver support system.     

Molecular cloning of cDNA for equine follistatin and its gene expression in the reproductive tissues of the mare.

A cDNA clone encoding equine follistatin was isolated from an equine ovarian cDNA library. Out of 1.2 x 10(5) independent clones screened, one positive clone was isolated and its cDNA sequence determined. The isolated clone, named EQ-FS-1, contained a complete open reading frame encoding 344 amino acid residues. The similarity of its deduced amino acid sequence to these of other mammalian species was greater than 95%. Although its expression level varied among the tissues examined, follistatin mRNA was detected in the equine uteroplacental tissues, follicles and corpora lutea by Northern blot analysis. In situ hybridization revealed that the expression of follistatin mRNA in the equine follicle was restricted exclusively to granulosa cells. When the expression pattern of follistatin mRNA in the equine uteroplacental tissues from mid- to late-pregnancy was examined, it was shown that its expression level tended to decrease after mid-pregnancy. These results suggest that follistatin acts in the reproductive tissues of the mare in maintaining pregnancy.     

Relationship between growth hormone (GH) pulses in the peripheral circulation and GH-releasing hormone and somatostatin profiles in the cerebrospinal fluid of goats

Growth hormone (GH) is secreted in a pulsatile manner, but the underlying mechanisms of GH pulse generation remain to be resolved. In the present study, we investigated the relationship between GH pulses in the peripheral circulation and GH-releasing hormone (GHRH) and somatostatin (SRIF) profiles in the cerebrospinal fluid (CSF) of male goats. The effects of an intracerebroventricular (icv) injection of neuropeptide Y (NPY), galanin and ghrelin were also analyzed. Blood and CSF samples were collected every 15 min for 8 hr from the jugular vein and third ventricle, respectively. GH pulsatility in the goat was found to consist of distinct large pulses of 5 hr periodicity and small pulses of 1 hr periodicity. GHRH and SRIF in the CSF fluctuated in a pulsatile manner with 1 hr periodicity, and most of the descending phase of SRIF pulses were associated with the initiation of GH pulses. Icv injections of NPY, galanin and ghrelin stimulated GHRH release without affecting SRIF release. In addition, NPY suppressed, and galanin and ghrelin induced large GH pulses, although ghrelin was much more effective than galanin. These results suggest that an hourly fall in SRIF is involved in generating intrinsic circhoral rhythm of GH pulsatility. The mechanisms underlying the generation of large GH pulses of 5 hr periodicity remain unknown, while direct action of NPY and/or ghrelin on the pituitary might be involved.