Rising testicular cancer incidence in Spain despite declining mortality: an age-period-cohort analysis.

BACKGROUND: Testicular cancer, primarily affecting young men, has seen an alarming rise globally. This study delves into incidence and mortality trends in Spain from 1990 to 2019 using the Global Burden of Disease (GBD) database and the Age-Period-Cohort (A-P-C) model. METHODS: We analyzed GBD data on testicular cancer cases and deaths in Spain, calculating age-standardized rates (ASIR and ASMR) and employing Joinpoint regression to identify significant shifts. The A-P-C model further dissected the effects of age, period, and birth cohort on these trends. RESULTS: A striking doubling in testicular cancer incidence was observed, from 3.09 to 5.40 per 100,000 men (1.9% annual increase), while mortality rates remained stable and even decreased in younger age groups (0.34 to 0.26 per 100,000, 0.8% annual decrease). Joinpoint analysis revealed four distinct periods of increasing incidence, with a recent slowdown. The A-P-C model highlighted a consistent rise in incidence risk with each successive generation born after 1935, contrasting with a progressive decline in mortality risk across cohorts, particularly marked for those born since the 1960s. CONCLUSION: While mortality rates are encouraging, Spain reflects the global trend of escalating testicular cancer incidence. The A-P-C analysis suggests a generational influence, but the underlying causes remain elusive. Further research is crucial to understand these trends and implement effective prevention strategies to combat this growing health concern.

Disease risk estimates in V30M variant transthyretin amyloidosis (A-ATTRv) from Mallorca.

BACKGROUND: Variant transthyretin amyloidosis (A-ATTRv) is an autosomal dominant disease caused by a range of TTR gene variants which entail great phenotypical heterogeneity and penetrance. In Majorca, the A-ATTRv caused by the V30M gene variant (A-ATTRV30M) is the most common. Since asymptomatic carriers are at risk of developing the disease, estimating age of onset is vital for proper management and follow-up. Thus, the aim of this study was to estimate age-related penetrance in ATTRV30M variant carriers from Majorca. METHODS: The disease risk among carriers from ATTRV30M families from Majorca was estimated by Non-parametric survival estimation. Factors potentially involved in the disease expression, namely gender and parent of origin were also analysed. RESULTS: A total of 48 heterozygous ATTRV30M families (147 affected patients and 123 were asymptomatic carriers) were included in the analysis. Penetrance progressively increased from 6% at 30 years to 75% at 90 years of age. In contrast to other European populations, we observe a similar risk for both males and females, and no difference of risk according to the parent of origin. CONCLUSIONS: In this first study assessing the age-related penetrance of ATTRV30M variant in Majorcan families, no effect of gender or parent of origin was observed. These findings will be helpful for improving management and follow-up of TTR variant carrier individuals.

[Paraneoplastic and disimmune sensory neuronopathies or ganglionopathies. Importance of an early detection]. / Ganglionopatías o neuronopatías sensoriales paraneoplásicas y disinmunes. Importancia de una detección temprana.

INTRODUCTION: Sensory ganglionopathies or sensory neuronopathies are subacute acquired diseases of the dorsal root ganglion, frequently associated with disinmune, paraneoplastic and toxic agents. Patients present sensory alteration of asymmetric distribution and early ataxia. Early identification is essential, as they may announce an underlying neoplasia or autoimmune disease. AIM: To study asymmetries of the sensory nervous action potential (SNAP) of nerve pairs and the relationship amplitude of ulnar sensory/ulnar motor potential (USMAR) with serial electroneurophysiological studies for the early diagnosis of sensory ganglionopathies. PATIENTS AND METHODS: Six patients with sensory ganglionopathies were retrospectively studied with electroneurophysiological studies: four paraneoplastic cases with positivity for onconeuronal antibodies, one associated with Sjogren's syndrome and two idiopathic. RESULTS: Electroneurophysiological studies showed axonal sensory involvement in all cases, with asymmetry > 50% in SNAP amplitude in two pairs of nerves in four cases and normal motor with USMAR < 0.71 in five cases. Serial electroneurophysiological studies were essential in the diagnosis of two cases in the beginning of the disease with mild sensory symptoms. CONCLUSIONS: This work evidences the importance of the study of asymmetries in the amplitude of the SNAP of nerve pairs, the USMAR and the serial electroneurophysiological studies in the early diagnosis of sensory ganglionopathies, to further identification of the disinmune and onconeuronal associated antibodies with the nervous system affection to search for hidden neoplasia.

TITLE: Ganglionopatías o neuronopatías sensoriales paraneoplásicas y disinmunes. Importancia de una detección temprana.Introducción. Las ganglionopatías o neuronopatías sensoriales son enfermedades subagudas adquiridas del ganglio raquídeo dorsal, frecuentemente asociadas con trastornos disinmunes y paraneoplásicos, y agentes tóxicos. Los pacientes presentan alteración sensorial de distribución asimétrica y ataxia temprana. La identificación temprana es esencial, ya que pueden anunciar una neoplasia subyacente o una enfermedad autoinmune. Objetivo. Estudiar las asimetrías del potencial de acción nervioso sensitivo (SNAP) de pares de nervios y la relación de amplitud del potencial de acción sensitivomotor del nervio cubital (USMAR) con estudios electroneurofisiológicos seriados para el diagnóstico precoz de las ganglionopatías sensoriales. Pacientes y métodos. Se estudió retrospectivamente a siete pacientes con ganglionopatías sensoriales con estudios electroneurofisiológicos: cuatro casos paraneoplásicos con positividad para anticuerpos onconeuronales, uno asociado al síndrome de Sjögren y dos idiopáticos. Resultados. Los estudios electroneurofisiológicos mostraron afectación sensorial axonal en todos los casos, con asimetría mayor del 50% en la amplitud de SNAP en dos pares de nervios en cuatro casos y motor normal con USMAR menos de 0,71 en cinco casos. Los estudios electroneurofisiológicos seriados fueron esenciales en el diagnóstico de dos casos en el inicio de la enfermedad con síntomas sensoriales leves. Conclusiones. Este trabajo evidencia la importancia del estudio de asimetrías en la amplitud del SNAP de pares de nervios, la USMAR y los estudios electroneurofisiológicos seriados en el diagnóstico temprano de ganglionopatías sensoriales, para la consiguiente identificación de los anticuerpos disinmunes y onconeuronales con afectación del sistema nervioso periférico y la búsqueda de neoplasia oculta.

Epidemiological study of primary systemic vasculitides among adults in southern Spain and review of the main epidemiological studies.

OBJECTIVES: To study the incidence and prevalence of primary systemic vasculitides (PSV) in the Costa del Sol region (southern Spain) and to compare the major epidemiological studies in PSV with the results obtained in our area. METHODS: Retrospective study including permanent residents ≥14 years (or older) diagnosed with PSV at the Hospital Costa del Sol (Marbella, Spain) between 1994 and 2010. Epidemiological data were collected and the annual incidence rate during the study period and the prevalence in 2010 were calculated per million population, except for GCA, which was estimated per 100,000 population >50 years. RESULTS: Seventy-four adult patients were diagnosed with PSV, representing an annual incidence of 15.8 (95%CI 12.2-19.4) patients/million population. These diagnoses included 29 (39.1%) giant cell arteritis (GCA), 5 (6.7%) Takayasu's arteritis (TKA), 3 (4%) poly-arteritis nodosa (PAN), 29 (39.1%) antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) [10 (13.5%) granulomatosis with polyangiitis (GPA) (Wegener), 16 (21.6%) microscopic polyangiitis (MPA) and 3 (4%) eosinophilic granulomatosis with polyangiitis (EGPA) (Churg-Strauss)], 7 (9.4%) IgA vasculitis (Henoch-Schönlein) (IgAV) and one (1.3%) cryobulinaemic vasculitis (CV). The annual incidence and 2010 prevalence for each of the PSV, respectively, were: GCA: 2.2/12.2; TKA: 1.1/10.5; PAN: 0.6/2.6; AAV: 6.2/44.8 (GPA: 2.1/15.8; MPA: 3.4/23.8; EGPA: 0.6/5.3); IgAV: 1.5/7.9; and CV: 0.2/0. CONCLUSIONS: The first epidemiological study of PSV in southern Spain corroborates their infrequency, with GCA and AAV as the PSV most often diagnosed. In southern Spain, the incidence and prevalence of PSV are lower than in northern Spain and in countries in the Northern Hemisphere.

Influence of the IL17A locus in giant cell arteritis susceptibility.

OBJECTIVE: Different lines of evidence have highlighted the role of IL-17A in the inflammatory process occurring in giant cell arteritis (GCA). The aim of the present study was to assess whether the IL17A locus influences GCA susceptibility and its clinical subphenotypes. METHODS: We carried out a large meta-analysis including a total of 1266 biopsy-proven GCA patients and 3779 healthy controls from four European populations (Spain, Italy, Germany and Norway). Five IL17A polymorphisms (rs4711998, rs8193036, rs3819024, rs2275913 and rs7747909) were selected by tagging and genotyped using TaqMan assays. Allelic combination and dependency tests were also performed. RESULTS: In the pooled analysis, two of the five analysed polymorphisms showed evidence of association with GCA (rs2275913: PMH=1.85E-03, OR=1.17 (1.06-1.29); rs7747909: PMH=8.49E-03, OR=1.15 (1.04-1.27)). A clear trend of association was also found for the rs4711998 variant (PMH=0.059, OR=1.11 (1.00-1.23)). An independent effect of rs2275913 and rs4711998 was evident by conditional regression analysis. In addition, the haplotype harbouring the risk alleles better explained the observed association than the polymorphisms independently (likelihood p value <10(-05)). CONCLUSIONS: Polymorphisms within the IL17A locus show a novel association with GCA. This finding supports the relevant role of the Th17 cells in this vasculitis pathophysiology.

Identification of the PTPN22 functional variant R620W as susceptibility genetic factor for giant cell arteritis.

OBJECTIVE: To analyse the role of the PTPN22 and CSK genes, previously associated with autoimmunity, in the predisposition and clinical phenotypes of giant cell arteritis (GCA). METHODS: Our study population was composed of 911 patients diagnosed with biopsy-proven GCA and 8136 unaffected controls from a Spanish discovery cohort and three additional independent replication cohorts from Germany, Norway and the UK. Two functional PTPN22 polymorphisms (rs2476601/R620W and rs33996649/R263Q) and two variants of the CSK gene (rs1378942 and rs34933034) were genotyped using predesigned TaqMan assays. RESULTS: The analysis of the discovery cohort provided evidence of association of PTPN22 rs2476601/R620W with GCA (PFDR=1.06E-04, OR=1.62, CI 95% 1.29 to 2.04). The association did not appear to follow a specific GCA subphenotype. No statistically significant differences between allele frequencies for the other PTPN22 and CSK genetic variants were evident either in the case/control or in stratified case analysis. To confirm the detected PTPN22 association, three replication cohorts were genotyped, and a consistent association between the PTPN22 rs2476601/R620W variant and GCA was evident in the overall meta-analysis (PMH=2.00E-06, OR=1.51, CI 95% 1.28 to 1.79). CONCLUSIONS: Our results suggest that the PTPN22 polymorphism rs2476601/R620W plays an important role in the genetic risk to GCA.

A case-control study suggests that the CCR6 locus is not involved in the susceptibility to giant cell arteritis.

OBJECTIVES: Polymorphisms of the CC chemokine receptor 6 (CCR6) gene have been recently reported to be associated with a number of autoimmune diseases. We aimed to investigate the possible influence of CCR6 rs3093024 gene variant in the susceptibility to and clinical expression of GCA. METHODS: The CCR6 polymorphism rs3093024 was genotyped in a total of 463 Spanish patients diagnosed with biopsy-proven GCA and 920 healthy controls using a TaqMan® allelic discrimination assay. PLINK software was used for the statistical analyses. RESULTS: No significant association between this CCR6 variant and GCA was observed (p=0.42, OR=0.94, CI95% 0.79-1.10). Similarly, when patients were stratified according to the specific clinical features of GCA such as polymyalgia rheumatica, visual ischaemic manifestations or irreversible occlusive disease, no statistical significant difference was detected either between the case subgroups and the control set or between GCA patients with and without the specific features of the disease. CONCLUSIONS: Our results suggest that the CCR6 rs3093024 polymorphism may not play a relevant role in the GCA pathophysiology.

Increased expression of the endothelin system in arterial lesions from patients with giant-cell arteritis: association between elevated plasma endothelin levels and the development of ischaemic events.

OBJECTIVE: Approximately 15-20% of patients with giant-cell arteritis (GCA) develop ischaemic complications often preceded by transient ischaemia. The expression of the endothelin (ET) system in GCA lesions was investigated to assess its relationship with the development of ischaemic complications. METHODS: Plasma ET-1 was quantified by immunoassay in 61 patients with biopsy-confirmed GCA and 16 healthy donors. ET-1, endothelin-converting enzyme (ECE-1) and endothelin receptor (ET(A)R and ET(B)R) messenger RNA were measured by real-time quantitative reverse transcriptase-PCR in temporal arteries from 35 of these patients and 19 control arteries. Proteins were measured by immunoassay and Western blot. RESULTS: ET-1 concentration was increased at the protein level in temporal artery samples from GCA patients compared with controls (0.98 (SEM 0.32) vs 0.28 (SEM 0.098) fmol/mg, p = 0.028). ECE-1, ET(A)R and ET(B)R/actin ratios (Western blot) were also significantly higher in GCA patients. Intriguingly, mRNA expression of ET-1, ECE-1 and both receptors was significantly reduced in GCA lesions compared with control arteries. When investigating mechanisms underlying these results, platelet-derived growth factor and IL-1beta, present in GCA lesions, were found to downregulate ET-1 mRNA in cultured human temporal artery-derived smooth muscle cells. Glucocorticoid treatment for 8 days did not result in significantly decreased endothelin tissue concentration (0.87 (SEM 0.2) vs 0.52 (SEM 0.08); p = 0.6). Plasma endothelin concentrations were higher in patients with ischaemic complications (1.049 (SEM 0.48) vs 1.205 (SEM 0.63) pg/ml, p = 0.032). CONCLUSIONS: The endothelin system is increased at the protein level in GCA lesions creating a microenvironment prone to the development of ischaemic complications. Recovery induced by glucocorticoids is delayed, indicating persistent exposure to endothelin during initial treatment.

Arteriovenous malformation of the brain mimicking primary central nervous system vasculitis.

In the diagnosis of primary central nervous system (CNS) vasculitis, it is crucial to rule out clinical, angiographic, and pathological mimics. We report a case of arteriovenous malformation (AVM) mimicking primary CNS vasculitis. A young male presented with intracerebral haemorrhage and no other clinical, laboratory, or angiographic features suggesting vasculitis. Cerebral biopsy showed perivascular inflammation and slight infiltration of the muscular layer of cerebral vessels by chronic inflammatory cells close to the haemorrhagic areas. These findings led to a diagnosis of CNS vasculitis. The patient was initially treated with corticosteroids, but 10 months after the discovery and surgical repair of the AVM, the patient is not receiving any immunosuppressant and has not developed any features of cerebral or systemic vasculitis.

Association between increased CCL2 (MCP-1) expression in lesions and persistence of disease activity in giant-cell arteritis.

OBJECTIVE: Patients with giant-cell arteritis (GCA) usually respond dramatically to corticosteroid treatment. However, recurrences are frequent and corticosteroid requirements are highly variable among patients. The aim of our study was to identify genes potentially involved in disease persistence. METHODS: Gene expression was explored with cDNA arrays in temporal artery biopsies from six GCA patients with relapsing disease and six patients who easily achieved sustained remission. Differentially expressed genes of interest were subsequently analysed by quantitative real-time polymerase chain reaction (PCR) and immunohistochemistry in temporal artery biopsies from 35 patients with biopsy-proven GCA and nine controls. RESULTS: CCL2 (MCP-1) was up-regulated in temporal artery samples from relapsing individuals. In the extended series of patients, CCL2 mRNA concentration in lesions was significantly higher than in controls (31 +/- 15.6 vs 0.44 +/- 0.10, P = 0.0001). In addition, CCL2 was more abundant in patients who experienced two or more relapses during the first year compared with those who endured sustained remission (127 +/- 82 vs 11 +/- 5.5, P = 0.0233) and correlated with the cumulated prednisolone dose (R = 0.533, P = 0.0024). CCL2 mRNA concentration correlated with IL-1beta (R = 0.45, P = 0.02), tumour necrosis factor-alpha (TNF-alpha) (R = 0.47, P = 0.013) and IL-6 (R = 0.52, P = 0.0053) mRNA. However, circulating CCL2 determined by ELISA was decreased in patients with strong systemic inflammatory response, suggesting that reduction in circulating CCL2 may reinforce the local gradient in lesions. CONCLUSION: Increased CCL2 (MCP-1) expression in lesions is associated with persistence of disease activity in GCA.

Tissue production of pro-inflammatory cytokines (IL-1beta, TNFalpha and IL-6) correlates with the intensity of the systemic inflammatory response and with corticosteroid requirements in giant-cell arteritis.

OBJECTIVES: To investigate proinflammatory cytokine expression in temporal arteries from patients with giant-cell arteritis (GCA) and to analyse its relationship with the intensity of the initial systemic inflammatory reaction and response to corticosteroid therapy. METHODS: Quantification of interleukin-1beta (IL-1beta), tumor necrosis factor alpha (TNFalpha), and interleukin-6 (IL-6) mRNA by real-time quantitative PCR in temporal artery samples from 36 patients with biopsy-proven GCA and 11 controls. Immunohistochemical detection of IL-1beta, TNFalpha, and IL-6 in temporal artery sections from 74 patients with GCA and 15 controls. Clinical and biochemical parameters of inflammation as well as the time (weeks) required to reach a maintenance prednisone dose <10 mg/day were recorded. RESULTS: IL-1beta (13.8 +/- 2.5 vs 5.4 +/- 1.3 relative units, P = 0.012) and IL-6 transcripts (34 +/- 13.7 vs 7.8 +/- 4.5 relative units, P = 0.034) were significantly more abundant in patients with a strong systemic inflammatory response compared with those with no inflammatory parameters. Immunohistochemical scores for IL-1beta (2.7 +/- 0.3 vs 1.9 +/- 0.2, P = 0.018), TNFalpha (3.2 +/- 0.2 vs 2.4 +/- 0.3, P = 0.028) and IL-6 (3 +/- 0.2 vs 2.1 +/- 0.3, P = 0.023) were also significantly higher in patients with strong systemic inflammatory reaction. A significant correlation was found between the amount of tissue TNFalpha mRNA and the time required to reach a maintenance dose of prednisone <10 mg/day (r = 0.586, P = 0.001). CONCLUSION: GCA patients with a strong systemic inflammatory response, who have been previously shown to be more resistant to corticosteroid therapy, have elevated tissue expression of proinflammatory cytokines IL-1beta, TNFalpha and IL-6. High production of TNFalpha is associated with longer corticosteroid requirements.

A multicenter, randomized, double-blind, placebo-controlled trial of adjuvant methotrexate treatment for giant cell arteritis.

OBJECTIVE: To evaluate treatment with methotrexate (MTX) in patients with newly diagnosed giant cell arteritis (GCA) to determine if MTX reduces GCA relapses and cumulative corticosteroid (CS) requirements and diminishes disease- and treatment-related morbidity. METHODS: This was a multicenter, randomized, double-blind study. Over 4 years, 16 centers from the International Network for the Study of Systemic Vasculitides enrolled patients with unequivocal GCA. The initial treatment was 1 mg/kg/day (

Small-vessel vasculitis surrounding a spared temporal artery: clinical and pathological findings in a series of twenty-eight patients.

OBJECTIVE: Occasionally, a temporal artery biopsy reveals small-vessel vasculitis (SVV) surrounding a spared temporal artery, the significance of which is unclear. We analyzed the final diagnosis in a series of patients with this condition and tried to identify histopathologic features with potential usefulness in predicting the ultimate diagnosis. METHODS: We performed a clinical and histopathologic review of 28 patients in whom SVV surrounding a spared temporal artery was the first histologic finding that led to the diagnosis of vasculitis. For comparison purposes, we analyzed the pattern of small vessel involvement in 30 patients with biopsy-proven giant cell arteritis (GCA). RESULTS: GCA was considered the most likely diagnosis in 12 patients, based on the absence of clinical evidence of additional organ involvement and normal findings on muscle biopsy and electrophysiologic study. Three patients had systemic necrotizing vasculitis (SNV), based on the demonstration of typical lesions on subsequent muscle, nerve, or kidney biopsy. After extensive evaluation, 4 patients remained unclassifiable. Nine patients were incompletely studied. Fibrinoid necrosis was significantly more frequent in patients with SNV (P = 0.0022), whereas involvement of vasa vasorum was more frequent in patients classified as having GCA (P = 0.022). No differences in the pattern of small vessel involvement were found in patients with SVV surrounding a spared temporal artery who were classified as having GCA compared with patients with biopsy-proven GCA. Granulocytes were observed at similar frequency in all conditions. CONCLUSION: SVV may be the only abnormal feature in a temporal artery biopsy and the only histologic evidence of vasculitis. The diagnosis of GCA can be reasonably established in most of these patients when there is no apparent evidence of additional organ involvement. However, when fibrinoid necrosis is observed or the temporal artery vasa vasorum are not involved, SNV must be extensively excluded.

Cell adhesion molecules in the development of inflammatory infiltrates in giant cell arteritis: inflammation-induced angiogenesis as the preferential site of leukocyte-endothelial cell interactions.

OBJECTIVE: To investigate the expression pattern of adhesion molecules involved in leukocyte-endothelial cell interactions in giant cell arteritis (GCA). METHODS: Immunohistochemical analysis was performed on frozen temporal artery sections from 32 patients with biopsy-proven GCA and from 12 control patients with other diseases. Adhesion molecules identified were intercellular adhesion molecule 1 (ICAM-1), ICAM-2, ICAM-3, vascular cell adhesion molecule 1 (VCAM-1), platelet endothelial cell adhesion molecule 1 (PECAM-1), E-selectin, P-selectin, L-selectin, lymphocyte function-associated antigen 1 (LFA-1), very late activation antigen 4 (VLA-4), Mac-1 (CD18/CD11b), and gp 150,95 (CD18/CD11c). Clinical and biochemical parameters of inflammation in the patients, as well as the duration of previous corticosteroid treatment, were prospectively recorded. RESULTS: Constitutive (PECAM-1, ICAM-1, ICAM-2, and P-selectin) and inducible (E-selectin and VCAM-1) endothelial adhesion molecules for leukocytes were mainly expressed by adventitial microvessels and neovessels within inflammatory infiltrates. Concurrent analysis of leukocyte receptors indicated a preferential use of VLA-4/VCAM-1 and LFA-1/ICAM-1 at the adventitia and Mac-1/ICAM-1 at the intima-media junction. The intensity of inducible endothelial adhesion molecule expression (E-selectin and VCAM-1) correlated with the intensity of the systemic inflammatory response. Previous corticosteroid treatment reduced, but did not completely abrogate, the expression of the inducible endothelial adhesion molecules E-selectin and VCAM-1. CONCLUSION: Inflammation-induced angiogenesis is the main site of leukocyte-endothelial cell interactions leading to the development of inflammatory infiltrates in GCA. The distribution of leukocyte-endothelial cell ligand pairs suggests a heterogeneity in leukocyte-endothelial cell interactions used by different functional cell subsets at distinct areas of the temporal artery.

Regulation of glial Na+/K+-ATPase by serotonin: identification of participating receptors.

The purpose of the present study was the characterization of the receptors participating in the regulatory mechanism of glial Na+/K+-ATPase by serotonin (5-HT) in rat brain. The activity of the Na+ pump was measured in four brain regions after incubation with various concentrations of serotoninergic agonists or antagonists. A concentration-dependent increase in enzyme activity was observed with the 5-HT1A agonist R (+)-2-dipropylamino-8-hydroxy-1,2,3, 4-tetrahydronaphthalene hydrobromide (8-OH-DPAT) in homogenates or in glial membrane enriched fractions from cerebral cortex and in hippocampus. Spiperone, a 5-HT1A antagonist, completely inhibited the response to 8-OH-DPAT but had no effect on Na+/K+-ATPase activity in cerebellum where LSD, a 5-HT6 agonist, elicited a dose-dependent response similar to that of 5-HT. In brainstem, a lack of response to 5-HT and other agonists was confirmed. Altogether, these results show that serotonin modulates glial Na+/K+-ATPase activity in the brain, apparently not through only one type of 5-HT receptor. It seems that the receptor system involved is different according to the brain region. In cerebral cortex, the response seems to be mediated by 5-HT1A as well as in hippocampus but not in cerebellum where 5-HT6 appears as the receptor system involved.

Brain serotonin synthesis and Na+,K+-ATPase activity are increased postnatally after prenatal administration of L-tryptophan.

The effect of prenatal L-tryptophan supplementation on the serotonin (5-HT) synthesis and the activity of Na+,K+-ATPase in the cerebral cortex was studied during postnatal development, from birth up to day 30. A parallel and significant elevation of the serotonin content and the activity of tryptophan-5-hydroxylase was observed in the brain of infant rats born to mothers treated with L-tryptophan, as related to non-treated controls. The activity of Na+,K+-ATPase was also significantly elevated at the different ages studied throughout the developmental period, as related to controls. These results suggest an important role of L-tryptophan in the early regulation of the serotonin-synthesizing machinery, which lasts postnatally. Elevation of ATPase activity seems to be associated to the elevation in the activity of the 5-HT system.