Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P08908 (5-HT1A)
 5,574 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. The suprachiasmatic nucleus (SCN) of the hypothalamus is the primary pacemaker for circadian rhythms in mammals. The 24 h pacemaker is endogenous to the SCN and persists for multiple cycles in the suprachiasmatic brain slice. 2. While serotonin is not endogenous to the SCN, a major midbrain hypothalamic afferent pathway is serotonergic. Within this tract the dorsal raphe nucleus sends direct projections to the ventrolateral portions of the SCN. We investigated a possible regulatory role for serotonin in the mammalian circadian system by examining its effect, when applied at projection sites, on the circadian rhythm of neuronal activity in rat SCN in vitro. 3. Eight-week-old male rats from our inbred colony, housed on a 12 h light: 12 h dark schedule, were used. Hypothalamic brain slices containing the paired SCN were prepared in the day and maintained in glucose and bicarbonate-supplemented balanced salt solution for up to 53 h. 4. A 10(-11) ml drop of 10(-6) M-serotonin (5-hydroxytryptamine (5-HT) creatinine sulphate complex) in medium was applied to the ventrolateral portion of one of the SCN for 5 min on the first day in vitro. The effect of the treatment at each of seven time points across the circadian cycle was examined. The rhythm of spontaneous neuronal activity was recorded extracellularly on the second and third days in vitro. Phase shifts were determined by comparing the time-of-peak of neuronal activity in serotonin- vs. media-treated slices. 5. Application of serotonin during the subjective day induced significant advances in the phase of the electrical activity rhythm (n = 11). The most sensitive time of treatment was CT 7 (circadian time 7 is 7 h after 'lights on' in the animal colony), when a 7.0 +/- 0.1 h phase advance was observed (n = 3). This phase advance was perpetuated on day 3 in vitro without decrement. Serotonin treatment during the subjective night had no effect on the timing of the electrical activity rhythm (n = 9). 6. The specificity of the serotonin-induced phase change was assessed by treating slices in the same manner with a microdrop of serotonergic agonists, 5-carboxamidotryptamine, that targets the 5-HT1 class of receptors, or 8-hydroxy-dipropylaminotetralin (8-OH DPAT), that acts on the 5-HT1A receptor subtype.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Serotonin regulates the phase of the rat suprachiasmatic circadian pacemaker in vitro only during the subjective day. 143 21

Proestrous rats were infused unilaterally into the median raphe nucleus with 200-2,000 ng of the 5-HT1A agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT). Inhibition of the lordosis to mount ratio occurred within 15 and 10 min, respectively, following infusion with 1,000 or 2,000 ng of the drug. Infusion of 2,000 ng of the 5-HT2 agonist, (+/-)-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane HCl (DOI), or 4,000 ng 5-HT (creatinine sulfate) failed to substantially reduce lordosis behavior.
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PMID:Agonist activation of 5-HT1A receptors in the median raphe nucleus and female rat lordosis behavior. 770 14

1. The present study has examined the effect of (+)-WAY 100135, a selective antagonist of 5-HT1A receptors, and ketanserin, an antagonist of 5-HT2 receptors, on the urinary excretion of Na+, K+, dopamine, 5-hydroxytryptamine (5-HT) and their metabolites in rats treated with the selective type A monoamine oxidase (MAO-A) inhibitor, Ro 41-1049 (15 mg kg-1 day-1) in conditions of normal sodium (NS) and high sodium (HS; 1.0% NaCl in drinking water) intake. 2. Male Wistar rats were placed in metabolic cages and were given tap water (NS diet) in the first 4 days of the study and then challenged to a HS diet for another 7 days. Ro 41-1049 was given in drinking water only in the last 3 days of the HS diet, whereas (+)-WAY 100135 (5 and 10 mg kg-1 day-1, s.c.) or ketanserin (2 mg kg-1 day-1, s.c.) were administered in the last 4 days of the HS intake period. 3. Daily urinary excretion (in nmol kg-1 day-1) of dopamine (82 +/- 2), 3,4-dihydroxyphenylacetic acid (DOPAC; 198 +/- 9), homovanillic acid (HVA; 915 +/- 47), 5-HT (586 +/- 37) and 5-hydroxyindoleacetic acid (5-HIAA; 1035 +/- 64) in the HS intake period was similar or higher than that in NS diet (dopamine = 68 +/- 2, DOPAC = 197 +/- 4, HVA = 923 +/- 42, 5-HT = 539 +/- 132, 5-HIAA = 1286 +/- 95). The administration of Ro 41-1049 on 3 consecutive days reduced the urinary excretion of dopamine, DOPAC and HVA, respectively, by 35-51% (P < 0.05), 73-85% (P < 0.05) and 59-66% (P < 0.05); the urinary excretion of 5-HT increased 2 fold (P < 0.01) and the levels of 5-HIAA were reduced by 39-77% (P < 0.05). 4. During HS intake (7 days), daily urinary excretion of Na+ increased 5.5 fold (from 6.7 +/- 0.2 to 36.5 +/- 0.9 mmol kg-1 day-1), without changes in the urinary excretion of K+ (from 11.2 +/- 0.2 to 11.9 +/- 0.5 mmol kg-1 day-1) and urinary osmolality (from 1083.8 +/- 26.7 to 1117.7 +/- 24.1 mOsm kg-1 H2O). MAO-A inhibition during HS intake was found to produce a 47-68% decrease in Na+ excretion (from 39.1 +/- 0.7 to 15.1 +/- 2.5 mmol kg-1 day-1, n = 4; P < 0.02) and urine volume (from 160.4 +/- 3.3 to 43.8 +/- 9.0 ml kg-1 day-1, n = 4; P < 0.02) without changes in K+ (from 11.1 +/- 0.5 to 9.2 +/- 0.6 mmol kg-1 day-1, n = 4) and creatinine (from 29.1 +/- 2.3 to 28.4 +/- 2.1 mg kg-1 day-1) excretion; urine osmolality increased 2 fold (from 936.3 +/- 40.3 to 2210.7 +/- 157.4 mOsm kg-1 H2O, n = 4; P < 0.02). Administration of (+)-WAY 100135 (5 and 10 mg kg-1 day-1), but not of ketanserin (2 mg kg-1 day-1), was found to inhibit the antinatriuretic effect induced by Ro 41-1049 during HS intake. 5. It is suggested that MAO-A inhibition during HS intake leads to an increased availability of 5-HT in renal tissues, the effect of which is a decrease in the urinary excretion of Na+, involving the activation of tubular 5-HT1A receptors.
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PMID:Antagonistic actions of renal dopamine and 5-hydroxytryptamine: endogenous 5-hydroxytryptamine, 5-HT1A receptors and antinatriuresis during high sodium intake. 888 15