Disease relevance of Subfornical Organ

• The purpose of this study was to examine the contribution of the subfornical organ to the chronic hypertension produced by intravenous angiotensin II infusion in rats [1].
• Electrolytic lesions in the subfornical organ also reduce renin-dependent, two-kidney Goldblatt hypertension [2].
• The role of the subfornical organ (SFO) in drinking caused by cellular dehydration and angiotensin was examined in the dog [3].
• In contrast, significant increases in the BBB leakage of sodium fluorescein, a much smaller molecule, were observed 1 and 2 days after the induction of colitis, in and around the circumventricular organs; the organum vasculosum of the lamina terminalis, subfornical organ and median eminence of the hypothalamus [4].
• 3. Hypotension also releases renal renin and leads to the formation of angiotensin II; binding of this hormone to AT1 receptors on subfornical organ neurons promotes activation of a central angiotensinergic input that evokes a predominantly excitatory effect on vasopressin neurons [5].

Psychiatry related information on Subfornical Organ

• Water deprivation increases the expression of pituitary adenylate cyclase-activating polypeptide gene in the rat subfornical organ [6].
• Previous studies have shown that angiotensin II (ANG II) increases glucose utilization in the subfornical organ and stimulates drinking behavior [7].
• Systemic angiotensin II acts at the subfornical organ to suppress voluntary alcohol consumption [8].
• Self-stimulation of the subfornical organ and lateral hypothalamus: differential effects of atropine and methysergide [9].

High impact information on Subfornical Organ

• Subfornical organ: a dipsogenic site of action of angiotensin II [10].
• Circulating relaxin acts on subfornical organ neurons to stimulate water drinking in the rat [11].
• Relaxin administration resulted in increased Fos expression in the subfornical organ (SFO), organum vasculosum of the lamina terminalis (OVLT), median preoptic nucleus, and magnocellular neurons in the supraoptic and paraventricular nuclei [11].
• Angiotensin II receptors in paraventricular nucleus, subfornical organ, and pituitary gland of hypophysectomized, adrenalectomized, and vasopressin-deficient rats [12].
• LHRH neurons in the nucleus of the anterior commissure and the bed nucleus of the stria terminalis project over the anterior commissure to form a dense plexus of fibers in the subfornical organ [13].

Chemical compound and disease context of Subfornical Organ

• No change in glucose utilization after 2 days of water deprivation was apparent in the parvocellular paraventricular nucleus, periventricular nucleus of the hypothalamus, corpus callosum, organum vasculosum of the lamina terminalis (OVLT) or the subfornical organ (SFO) [14].
• The effect of water deprivation and salt loading on rat atrial natriuretic peptide (99-126) (rANP)-stimulated guanylate cyclase activity was investigated in the rat subfornical organ. rANP stimulated the formation of cGMP in rat subfornical organ crude homogenates in a dose- and time-dependent manner [15].
• Rats with transections of subfornical organ (SFO) efferent projections failed to drink to intravenous angiotensin-II (AII) but responded to intracellular dehydration and water deprivation and suppressed drinking when food deprived [16].
• An elevated responsiveness to rANP-induced cGMP production was observed in the subfornical organ after 4 days of water deprivation; on the contrary, after salt loading the response to the cGMP-generating effects of ANP were less pronounced than those in the corresponding control tissue [15].
• Effect of the arterial hypertension and captopril treatment on the angiotensin II content in the subfornical organ. A study in SHR rats [17].

Biological context of Subfornical Organ

• Decreased number and affinity of rat atrial natriuretic peptide (6-33) binding sites in the subfornical organ of spontaneously hypertensive rats [18].
• Water intake was significantly increased on the 3rd, 4th, and 5th days of angiotensin II infusion only in rats with lesions in the subfornical organ [1].
• Role of the subfornical organ in the relaxin-induced prolongation of gestation in the rat [19].
• Noradrenaline release in the rat subfornical organ area to blood pressure changes [20].
• The subfornical organ and relaxin-induced inhibition of reflex milk ejection in lactating rats [21].

Anatomical context of Subfornical Organ

• Lesions of the subfornical organ (SFO) severely attenuated drinking induced by injections of angiotensin II into the lateral ventricles, but a few days (4 to 14) later a recovery of the drinking response is observed [22].
• Pituitary hormone release may also be influenced by circulating angiotensin II through receptors outside the blood-brain barrier in the subfornical organ [12].
• When the relative concentrations of ANP binding sites were determined throughout the rat brain, the highest levels of ANP binding were localized to the circumventricular organs, including the area postrema and subfornical organ, and the olfactory apparatus [23].
• The subfornical organ (SFO) and the periventricular tissue of the anteroventral third ventricle (AV3V) have been shown to be important for the central action of circulating angiotensin [24].
• Krox-24 expression in the subfornical organ, median preoptic area, and paraventricular nucleus of SHR was also significantly increased compared with that in all control strains [25].

Associations of Subfornical Organ with chemical compounds

• ICV carbachol (Carb), on the other hand, did not elicit drinking before 4 days, despite the fact that these dipsogens (Carb and Ang II) may both affect receptors in the subfornical organ [26].
• The circumventricular organs, organum vasculosum lamina terminalis (OVLT) and subfornical organ (SFO), are potential sites that could detect increases in plasma lactate levels and activate the DMH [27].
• ANF was significantly decreased in seven brain areas in SHR at both ages investigated; the most pronounced decreases were found in the subfornical organ, in the perifornical and periventricular hypothalamic nuclei, and in the medial preoptic nucleus [28].
• In brain, ACE activity was markedly reduced 4 hours after lisinopril administration in the circumventricular organs, including the subfornical organ (16-22%) and organum vasculosum of the lamina terminalis (7%; p less than 0.05) [29].
• Control injections of losartan into areas adjacent to the subfornical organ had no effect on the responses to hypertonic saline [30].

Gene context of Subfornical Organ

• Expression of basic fibroblast growth factor and its receptor in the rat subfornical organ [31].
• Water deprivation upregulates ANG II AT1 binding and mRNA in rat subfornical organ and anterior pituitary [32].
• Dense amylin binding is present at the circumventricular organs, including the subfornical organ, the organum vasculosum lateralis terminalis (OVLT), and the area postrema [33].
• We now report that the subfornical organ, an important site of angiotensinogen synthesis, is an extra-hypothalamic site of TTF-1 expression [34].
• To characterize endothelin-specific receptors in astrocytes of both circumventricular organs, alterations in the intracellular calcium concentration due to endothelin-1/endothelin-3 stimulation were studied in primary culture of subfornical organ and organum vasculosum laminae terminalis cells obtained from early postnatal rat pups [35].

Analytical, diagnostic and therapeutic context of Subfornical Organ

• Double in situ hybridization histochemistry demonstrated the presence of TTF-1 mRNA in angiotensinogen-producing cells of the rat subfornical organ [34].
• Twenty-eight subfornical organ (SFO) neurons in ovariectomized (OVX) female rats that were treated with propylene glycol (PG) vehicle and 26 SFO neurons in OVX female rats that were treated with estrogen benzoate (EB) were antidromically activated by electrical stimulation of the hypothalamic paraventricular nucleus (PVN) under urethane anesthesia [36].
• To characterize the cell-specific distribution of angiotensin II receptors within the circumventricular organs, primary cell cultures derived from the subfornical organ or organum vasculosum laminae terminalis of five- to six-day-old rat pups were used to measure alterations in intracellular calcium at the single cell level [37].
• Increased Fos expression was also found in the subfornical organ after subcutaneous injection of either vasopressin or the desglycinamide analog [38].
• With the aid of light- and electron- microscopic immunocytochemistry, somatostatin- and luliberin (LRF)-positive fibers can be demonstrated in the rat subfornical organ (SFO) [39].

References