title: Secretion of testicular steroids and gonadotrophins in hypothyroidism.
abstract: Inconsistent alterations in gonadal steroidogenesis and pituitary functions have been reported in hypothyroid males. We have compared the lipid and endocrine profiles of the euthyroid and hypothyroid [thyroid-stimulating hormone (TSH) >100 mIU l(-1)] males. Hypothyroidism was found to be associated with an increase in the circulating level of total cholesterol and LDL-cholesterol (LDL-C) and a reduction in the levels of progesterone and testosterone, without any change in the serum levels of oestradiol and gonadotrophins. The failure of gonadotrophins to rise could be accounted by a normal level of serum oestradiol in the hypothyroid male. A mild hyperprolactinaemia was also noted in the hypothyroid patients. The reduction in serum testosterone level could be explained by (i) a reduced uptake of LDL-C by the Leydig cells and thereby a reduction in the synthesis of progesterone and consequentially testosterone, (ii) a further reduction in the rate of conversion of progesterone to testosterone, (iii) a higher rate of conversion of testosterone to oestradiol, (iv) a decrease in serum triiodothyronine and (v) hyperprolactinaemia. Rise in TSH needs to be investigated as a cause of the suppression of gonadal steroidogenesis.
authors: Department of Reproductive Biology, All India Institute of Medical Sciences, New Delhi, India. anandkumarrepbiol@hotmail.com
authors: A
authors: A
authors: Kumar
authors: B P
authors: BP
authors: Mohanty
authors: L
authors: L
authors: Rani
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D004958:Estradiol / Q000097:blood*; D005640:Follicle Stimulating Hormone / Q000097:blood; D006062:Gonadotropins / Q000097:blood*; D006801:Humans; D007037:Hypothyroidism / Q000097:blood*; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008875:Middle Aged; D011374:Progesterone / Q000097:blood*; D011388:Prolactin / Q000097:blood; D013739:Testosterone / Q000097:blood*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
chemical_list: D008078:Cholesterol, LDL; D006062:Gonadotropins; D014284:Triiodothyronine; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin; D002784:Cholesterol; D013974:Thyroxine