Could growth retardation in cystic fibrosis be partly due to deficient steroid and thyroid hormonogenesis?
Cystic fibrosis (CF) mainly affects Caucasians of northwestern-European ancestry with severe morbidity. The individuals are malnourished and growth retarded. The latter is thought to be the consequence of delayed maturation of the hypothalamic-pituitary-gonadal axis due to malnourishment. However, there is evidence that steroid and thyroid hormone syntheses may be impaired in CF. Thyrotropin stimulates the uptake and efflux of iodide before the halide is incorporated into thyroid hormones and it is becoming apparent that gonadotropins likewise mobilise chloride ions in Leydig cells prior to steroidogenesis. Since the primary defect causing CF is the mutated cystic fibrosis transmembrane conductance regulator (CFTR)--a chloride channel residing on the apical membrane of wet epithelia, the growth retardation in CF may in part be due to deficient hormone syntheses. The latter may involve CFTR or may be the halide channel activated by glycoprotein hormones prior to hormonogenesis.
Panesar
N S
NS
Department of Chemical Pathology, The Chinese University of Hong Kong, The Prince of Wales Hospital, Shatin, New Territories, China.
D003550:Cystic Fibrosis / Q000150:complications* / Q000235:genetics / Q000378:metabolism*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics / Q000378:metabolism; D005260:Female; D006130:Growth Disorders / Q000209:etiology* / Q000378:metabolism*; D006801:Humans; D017136:Ion Transport; D007985:Leydig Cells / Q000378:metabolism; D008297:Male; D008954:Models, Biological; D009154:Mutation; D011628:Puberty, Delayed / Q000209:etiology / Q000378:metabolism; D013256:Steroids / Q000096:biosynthesis*; D013963:Thyroid Hormones / Q000096:biosynthesis*
C505032:CFTR protein, human; D013256:Steroids; D013963:Thyroid Hormones; D019005:Cystic Fibrosis Transmembrane Conductance Regulator