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Journal Article 2006; 27(1-2): 157-161 PubMed PMID: 16648812 Citation  Keywords:  Animals, Cattle, Craniocerebral Trauma:metabolism, Female, Hemorrhage:metabolism, Hypothalamus:metabolism, Immunohistochemistry, Male, Radioimmunoassay, Rest:physiology, Sex Characteristics, Stress, Psychological:metabolism, Vasopressins:blood,.   

OBJECTIVES: This study investigates antidiuretic hormone (ADH) plasma concentration in bulls and heifers at rest, after transportation stress, trauma and massive hyper-acute hemorrhage at slaughter, with special attention to differences between sexes. We also quantified ADH concentration in the ADH-producing hypothalamic area.

SETTING AND DESIGN: The study was carried out on animals at the abattoir, exploiting the routinely procedure of slaughtering to obtain the experimental stressful conditions. The control group was represented by a group of animals matched for breed, age and gender.

RESULTS: ADH plasma values suggest that transportation stress has little or no effect in heifers in contrast to bulls. In both sexes ADH release increases after open head trauma due to stunning prior to slaughter. Hemorrhagic hyper-acute stress caused by bleeding induces a rapid hundredfold rise of ADH plasma concentration that becomes diergic (physiologically different between sexes), with males showing far higher values. Females show a higher ADH concentration in the hypothalamus.

MAIN FINDING: This study points out a difference in ADH output between bulls and heifers under conditions of severe hemorrhagic stress, as produced by severing of the neck vessels at slaughtering.

CONCLUSION: Extreme stress unmasks endocrine differences in bovine ADH release that may be relevant only during specific circumstances, such as fighting....

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Comparative Study 2003; 24(1-2): 9-14 PubMed PMID: 12743525 Citation  Keywords:  Animals, Brain Chemistry:drug effects, Female, Lipopolysaccharides:pharmacology, Neuropeptides:analysis, Putamen:chemistry, Rats, Rats, Wistar, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization:methods, Supraoptic Nucleus:chemistry, Vasopres.   

: The measure of neuropeptides is an important tool in biology to better define endocrine and neuroendocrine function. Traditionally most methods have relied on the development of specific antibodies. Newer molecular methodologies have used measures of gene expression of neuropeptide precursors, such as Northern blot, PCR or in situ hybridization analysis. Matrix-assisted laser desorption/ionization (MALDI) mass analysis is a novel powerful technique for investigation of neuropeptides. Multiple peptides and peptide forms can be detected simultaneously and with great sensitivity in tissue extracts or partially purified samples. We have now adapted a MALDI methodology for the direct measurement of neuropeptides on fresh tissue sections of rat brains. We have validated the method by examining peptidergic mass profiles of the supraoptic nucleus (SON) and caudate putamen hypothalamic regions. Interestingly, mass profiles showed that vasopressin, which is specifically present in the SON, is modulated when animals are treated with lipopolysaccharides. MALDI-MS on brain slides is a novel complementary technique for neurobiologists and endocrinologists in order to investigate the dynamic and regional distribution of neuropeptides during physiological events....

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Journal Article 2002; 23(1): 33-44 PubMed PMID: 11880860 Citation  Keywords:  Adult, Aged, Arginine Vasopressin:antagonists & inhibitors, Aspartic Acid Endopeptidases:metabolism, Female, Glucocorticoids:therapeutic use, Humans, Hypothalamus:metabolism, Male, Middle Aged, Nerve Tissue Proteins:metabolism, Neuroendocrine Secretory Pr.   

OBJECTIVES: We reported earlier that vasopressin (AVP) peptide expression is significantly decreased in the postmortem hypothalamus of glucocorticoid (GC) treated patients, while such a decrease was not observed in AVP prohormone (proAVP) expression. This indicated a GC-induced suppression of AVP synthesis at the posttranslational level. Here, we investigated in detail whether this decreased levels of AVP expression in GC treated patients might be due to the down regulation of the prohormone convertases PC-1 and PC-2, and the molecular chaperone 7B2, as was reported previously in some AVP-related disorders.

MATERIALS & METHODS: An immunocytochemical study was performed on post-mortem hypothalami of GC exposed patients and controls, in which quantification of proAVP, AVP, neurophysin (NP) and oxytocin (OXT) expression were done along with the quantification of PC1, PC2 and 7B2 expression in the paraventricular nucleus, by using a computerized image analysis system.

RESULTS: Expression of processed AVP in GC exposed patients was significantly decreased (p=0.021), while the amount of proAVP expression was unchanged. Despite the strong correlation between AVP and NP (the other cleavage product of proAVP) expression in the GC group (r=0.917, p=0.004), the mean NP immunoreactivity did not show a significant decrease in this group. Also the OXT expression was similar in both groups. Although in most of the GC treated patients, the expression intensities of PC1 and PC2 were decreased parallel to the decrease in AVP, the mean expression levels of neither of PC1 and PC2, nor of 7B2 were statistically different between the groups (p=0.20-0.80).

CONCLUSION: We conclude that the suppression of AVP expression by GCs is not mediated solely by the down regulation of PC1, PC2 or 7B2. Other mechanisms, which may contribute to the GC-induced posttranslational suppression of AVP, are discussed....

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Journal Article 2001; 22(3): 169-174 PubMed PMID: 11449194 Citation  Keywords:  Animals, Humans, Hypothalamus:drug effects, In Vitro Techniques, Melatonin:pharmacology, Oxytocin:biosynthesis, Photoperiod, Pineal Gland:physiology, Pituitary Gland, Posterior:drug effects, Vasopressins:biosynthesis,.   

: The present paper reviews the findings accumulated on the role of pineal gland and its hormone - melatonin - in regulation of the hypothalamo-neurohypophysial system activity. Effects of modified photoperiod, pinealectomy or treatment with melatonin on the vasopressin and oxytocin biosynthesis and/or secretion have been described. Taken together, the in vivo and in vitro data suggest that the effect of melatonin on the vasopressin and oxytocin secretion depends on this pineal hormone concentration and experimental conditions....

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