scholarly journals Development of thyroxine type II deiodinase activity in brains of Zucker rats

1994 ◽  
Vol 304 (1) ◽  
pp. 259-261 ◽  
Author(s):  
V Marie ◽  
F Dupuy ◽  
R Bazin

The present study was undertaken to determine whether the capacity for 3,5,3′,5′-tetraiodothyronine (T4) conversion into 3,5,3′-tri-iodothyronine (T3), as measured by the activity of thyroxine type II 5′-monodeiodinase (T4-5′D), was altered in the brains of young Zucker fa/fa rats during the period of intense maturation of the central nervous system (i.e. from 10 to 20 days of life). From 7 to 14 days of age, no difference in brain T4-5′D activity could be detected between lean and pre-obese rats; serum free T4 was not affected by the fa gene. During the suckling to weaning transition, T4-5′D reached a plateau in brains of lean rats, while it increased by 50% in brains of pre-obese rats; concurrently, serum free T4 increased in Fa/fa rats, whereas it did not change in fa/fa rats. The increased capacity for conversion of T4 into T3 observed in brains of pre-obese compared with lean rats could not be ascribed to a variation in the amount of T4-5′D, since Vmax. did not differ between the two genotypes; however, it could be totally accounted for by an increased affinity of the enzyme for T4. This change may represent an adaptive response to low serum free T4 in order to maintain the cerebral T3 concentration in pre-obese rats. These results show that the alteration in T4 metabolism in brains of fa/fa rats is not an early event and thus cannot interfere with maturation of the central nervous system. However, the decreased serum free T4 which was observed in pre-obese rats after suckling might play a secondary role in development of this genetic obesity.

2010 ◽  
Vol 79 (3) ◽  
pp. 1363-1373 ◽  
Author(s):  
Jianchun Xiao ◽  
Lorraine Jones-Brando ◽  
C. Conover Talbot ◽  
Robert H. Yolken

ABSTRACTStrain type is one of the key factors suspected to play a role in determining the outcome ofToxoplasmainfection. In this study, we examined the transcriptional profile of human neuroepithelioma cells in response to representative strains ofToxoplasmaby using microarray analysis to characterize the strain-specific host cell response. The study of neural cells is of interest in light of the ability ofToxoplasmato infect the brain and to establish persistent infection within the central nervous system. We found that the extents of the expression changes varied considerably among the three strains. Neuroepithelial cells infected withToxoplasmatype I exhibited the highest level of differential gene expression, whereas type II-infected cells had a substantially smaller number of genes which were differentially expressed. Cells infected with type III exhibited intermediate effects on gene expression. The three strains also differed in the individual genes and gene pathways which were altered following cellular infection. For example, gene ontology (GO) analysis indicated that type I infection largely affects genes related to the central nervous system, while type III infection largely alters genes which affect nucleotide metabolism; type II infection does not alter the expression of a clearly defined set of genes. Moreover, Ingenuity Pathways Analysis (IPA) suggests that the three lineages differ in the ability to manipulate their host; e.g., they employ different strategies to avoid, deflect, or subvert host defense mechanisms. These observed differences may explain some of the variation in the neurobiological effects of different strains ofToxoplasmaon infected individuals.


Author(s):  
Christian J. Hendriksz ◽  
Francois Karstens

There are 8 different types of diseases of the mucopolysaccharides, each caused by a deficiency in one of 10 different enzymes involved in the degradation of glycosaminoglycans (GAGs). Partially degraded GAGs accumulate within the lysosomes of many different cell types and lead to clinical symptoms and excretion of large amounts of GAGs in the urine. Heritability is autosomal recessive except for MPS type II, which is X-linked. The disorders are chronic and progressive and, although the specific types all have their individual features, they share an abundance of clinical similarities. All involve the musculoskeletal, the cardiovascular, the pulmonary and the central nervous system.


1999 ◽  
Vol 96 (3) ◽  
pp. 307-312 ◽  
Author(s):  
Simon DRYDEN ◽  
Peter KING ◽  
Lucy PICKAVANCE ◽  
Patrick DOYLE ◽  
Gareth WILLIAMS

Leptin inhibits feeding and decreases body weight. It may act partly by inhibiting hypothalamic neurons that express neuropeptide Y, a powerful inducer of feeding and obesity. These neuropeptide Y neurons express the Ob-Rb leptin receptor and are overactive in the fatty (fa/fa) Zucker rat. The fa mutation affects the extracellular domain of the leptin receptor, but its impact on leptin action and neuropeptide Y neuronal activity is not fully known. We compared the effects of three doses of leptin given intracerebroventricularly and three doses of leptin injected intraperitoneally on food intake and hypothalamic neuropeptide Y mRNA, in lean and fatty Zucker rats. In lean rats, 4-h food intake was reduced in a dose-related fashion (P< 0.01) by all intracerebroventricular leptin doses and by intraperitoneal doses of 300 and 600 μg/kg. Neuropeptide Y mRNA levels were reduced by 28% and 21% after the highest intracerebroventricular and intraperitoneal doses respectively (P< 0.01 for both). In fatty rats, only the highest intracerebroventricular leptin dose reduced food intake (by 22%; P< 0.01). Neuropeptide Y mRNA levels were 100% higher in fatty rats than in lean animals, and were reduced by 18% (P< 0.01) after the highest intracerebroventricular leptin dose. Intraperitoneal injection had no effect on food intake and neuropeptide Y mRNA. The fa/fa Zucker rat is therefore less sensitive to leptin given intracerebroventricularly and particularly intraperitoneally, suggesting that the fa mutation interferes both with leptin's direct effects on neurons and its transport into the central nervous system. Obesity in the fa/fa Zucker rat may be partly due to the inability of leptin to inhibit hypothalamic neuropeptide Y neurons.


PLoS ONE ◽  
2012 ◽  
Vol 7 (6) ◽  
pp. e39336 ◽  
Author(s):  
Kathleen R. Allinson ◽  
Hye Shin Lee ◽  
Marcus Fruttiger ◽  
Joseph McCarty ◽  
Helen M. Arthur

2001 ◽  
Vol 17 (1) ◽  
pp. 208-225 ◽  
Author(s):  
Frank R. Neumann ◽  
Godela Bittcher ◽  
Maik Annies ◽  
Beat Schumacher ◽  
Stephan Kröger ◽  
...  

2021 ◽  
Vol 11 (1(39)) ◽  
pp. 58-64
Author(s):  
Anastasiya Babintseva ◽  
Yu.Yu. Khodzinska ◽  
І.V. Lastivka ◽  
О.І. Yurkiv ◽  
A.I. Roshka ◽  
...  

Arnold-Chiari malformation is a defectof the cervical-medullar transition characterized bydisplacement of the cerebellar tonsils and in a numberof cases when the stem and IV ventricle extend into theforamen magnum. There are four main types of pathology,and type II is found most often.The article presents a clinical case of type II ArnoldChiari malformation in siblings. The newborn girl born afterVII pregnancy and VII physiological delivery in the termof 39-40 weeks was under observation. US examination inthe terms of 20-21 and 34 weeks of gestation diagnoseda congenital developmental defect of the central nervoussystem characterized by a “lemon”-like shape of the brain,displacement of the brain structures in the portion of theforamen magnum, ventriculomegaly, a defect of the lumbarsacral portion with formation of hernia sac, and dropsy ofamnion. The family couple refused from interruption ofpregnancy and medical-genetic examination.The basic diagnosis of the child was congenitaldevelopmental defect of the central nervous system(type II Arnold-Chiari malformation: rachischisis andhydrocephalus) including complications such as inferiortorpid paraplegia and dysfunction of the pelvic organs.Investigation of hereditary anamnesis foundcompromised heredity on the mother’s side (her mother’ssibling has Down’s syndrome), and IV child in the familyis disabled from birth due to a congenital developmentaldefect of the central nervous system – type II Arnold-Chiarimalformation.The family couple refused from a comprehensivemedical-genetic consultation during the previous andcurrent pregnancies, and magnetic-resonance imaging ofthe child.


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