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V1a Receptor mRNA (v1a + receptor_mrna)
Selected AbstractsAgeing and the Diurnal Expression of the mRNAs for Vasopressin and for the V1a and V1b Vasopressin Receptors in the Suprachiasmatic Nucleus of Male RatsJOURNAL OF NEUROENDOCRINOLOGY, Issue 6 2004T. Kalamatianos Abstract Changes in the function of neuropeptide synthesizing cells within the suprachiasmatic nucleus (SCN), the site of the predominant circadian pacemaker, may underlie the disturbance of rhythms observed during ageing. Arginine vasopressin (AVP) is synthesized by nearly one-third of SCN neurones in the rat. This peptide has predominantly excitatory actions within the SCN mediated by V1 -type receptors; the extent to which the V1a and/or V1b receptor subtypes are involved in SCN functions remains to be determined. The present study used isotopic in situ hybridization histochemistry to examine the effects of ageing on expression of mRNAs for AVP and V1a in the SCN and for V1b in the SCN and supraoptic nucleus (SON) of male rats kept under a 12 : 12 h light/dark cycle. Analysis of film autoradiographs from young adult (2,3-month-old; n = 40) or aged (19,20-month-old; n = 40) animals, at eight time points across the light/dark cycle, revealed an equivalent pattern and amplitude for the diurnal rhythm of AVP mRNA in the SCN of the young adult and aged groups. Both groups also displayed a significant diurnal rhythm in the expression of V1a receptor mRNA; however, the amplitude of this rhythm was reduced in the aged group, due to increased levels during the light phase and early part of night. Although the expression of V1b mRNA did not display a significant diurnal rhythm within the SCN or SON, persistently elevated levels for V1b mRNA were observed in the aged group at both sites. [source] The role of arginine vasopressin in human labour: functional studies, fetal production and localisation of V1a receptor mRNABJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 1 2002S. Thornton Objective To investigate labour-associated changes in: 1. the myometrial contractile response to arginine vasopressin compared with oxytocin in vitro 2. fetal production of arginine vasopressin and 3. myometrial vasopressin V1a receptor mRNA. Design The contractile response to vasopressin (compared with oxytocin) was investigated in paired myometrial strips in vitro. Blood was taken from the umbilical artery and vein at delivery and arginine vasopressin measured by radio-immunoassay. V1a receptor mRNA was determined by in situ hybridisation. Results Myometrium was more sensitive to arginine vasopressin than oxytocin (P <0.05 for frequency, amplitude and activity integral in paired strips) after, but not before labour. There was a marked umbilical arteriovenous difference in arginine vasopressin concentration at delivery suggesting fetal production which was not influenced by labour. Myometrial vasopressin V1a receptor mRNA was not increased after the onset of labour. Conclusions The human uterus is extremely sensitive to arginine vasopressin in vitro. Arginine vasopressin is produced by the fetus but fetal formation is not increased during labour. [source] | ||||||||||