Vasopressin mRNA in the cerebellum and circumventricular organs: a quantitative in situ hybridization study

Excitatory action of the bird antidiuretic hormone vasotocin on neurons in the subfornical organ

“…This possibility is supported by the identification of immunoreactive AVP containing fibres in the SFO of rats (Laczi et al 1983;Weindl and Sofroniew 1985) and pigeons (Weindl and Sofroniew 1982). Furthermore, a recent in situ hybridization study (Lepetit et al 1993) measuring mRNA for AVP in the rat SFO and the observation that the AVP content of the SFO increased after blockade of the peptide transport by colchicine (SummyLong et al 1984) suggest that at least some of the production sites of AVP are in cell bodies localized within the SFO. In addition, a reciprocal innervation of the SFO with ADH synthesizing hypothalamic nuclei in rats and ducks (Lind et al 1982;Miiller et al 1994) offers the possibility that AVP from magnocellular hypothalamic neurons might be released in the SFO.…”

“…The involvement of ADH in SFO mediated responses is further suggested by the presence ofmRNA for ADH in the rat SFO as recently revealed by in situ hybridization studies (Lepetit et al 1993). In addition, vasopressinergic and vasotocinergic fibers have been described in rats and pigeons Sofroniew 1982, 1985) and the content of ADH in the SFO increases after colchicine treatment (Summy-Long et al 1984).…”

Generation of the Melatonin Endocrine Message in Mammals: A Review of the Complex Regulation of Melatonin Synthesis by Norepinephrine, Peptides, and Other Pineal Transmitters

“…The pineal gland of the Syrian hamster, but not the rat, displays a few cells containing secretoneurin (SN) (Simonneaux et al, 1997a). The presence of VP in pineal cells is a matter of discussion since the mRNA coding for VP has been detected in the pineal gland of rat (Lepetit et al, 1993), sheep (Matthews et al, 1993), and cow (Olcese et al, 1993), but no VP-IR cells have yet been observed. This suggests that VP is synthesized in low amounts in pineal cells, the mRNA is present but not translated, or the mRNA is present in VPergic neural fibers but not in pineal cells.…”

“…Recently, using more sensitive molecular biology tools (RT-PCR and ISH), it has also been proposed that VP is synthesized in pineal cells. Vpm-RNA has been observed in the pineal gland of the rat (Lepetit et al, 1993), cow (Olcese et al, 1993;Badiu et al, 1999), and sheep (Matthews et al, 1993). Several hypotheses can explain that, in contrast, VP-IR cells are absent in the pineal gland: the quantity of synthesized VP is too low to be detected by immunocytochemistry; the VpmRNA is not translated into a peptide, and the detected mRNA is not present in cells but in the nerve endings, as observed in the pituitary (Mohr and Richter, 1993).…”

Vasopressin Acts in the Subfornical Organ to Decrease Blood Pressure

“…In addition, destruction of SFO inhibits VP responses to plasma hypertonicity [16] , Extracellular single unit recordings from antidromically identified putative VP neurons demonstrated that electrical stimulation of SFO increased the excitability of the majority of these VP neurons [17], Evidence suggesting that VP may be involved in the control of BP at the level of the SFO is derived from a variety of sources. Tritiated arginine VP-binding sites have been demonstrated within SFO tissue slices [4], Dis sociated SFO neurons tested with arginine VP have shown significant increases in internal Ca2+ concentra tions suggesting the existence of functional V| receptors [4], VP mRNA [ 18] and, more specifically, the Vla mRNA [19] signal have been localized within the SFO using in situ hybridization histochemistry. Preliminary in vitro electrophysiological studies suggest that VP application to SFO neurons in rat brain slices influences the activity of the majority of SFO neurons tested [20], Vasopressin Acts in the Subfornical Organ to Decrease Blood Pressure Therefore, the above studies suggest SFO involvement in BP regulation and the control of VP secretion from cen tral autonomic nuclei.…”