We have investigated a thiamine-dependent enzyme, transketolase, in cultured fibroblasts from 41 human subjects, including patients with alcoholism-associated Wernicke-Korsakoff syndrome (n = 3), familial chronic alcoholic males (a = 7), their sons (n = 7), nonalcoholic men (n = 7), their male offspring (a = 7), and three generations of an Amish family (n = 10)
We compared the adrenal steroid responses after synthetic ACTH-(1-24) (Cosyntropin) administration given by either continuous iv infusion or bolus injection in 11 normal women and 6 normal men. Each subject received 250 micrograms Cosyntropin as a bolus iv injection on 1 occasion and as a continuous 2-h iv infusion on another occasion, in random order. There was a 1-week interval between the studies. We measured the plasma levels of cortisol, 11-deoxycortisol, 17-hydroxyprogesterone, progesterone, pregnenolone, 17-hydroxypregnenolone, dehydroepiandrosterone, dehydroepiandrosterone sulfate, delta 5-androstenediol, androstenedione, and testosterone by RIA 15 and 0 min before and 30, 45, 60, and 120 min after administering ACTH. The steroid concentrations and their increments, ratios, or areas above baseline did not differ significantly between the bolus injection and the continuous infusion. Thus, at the dose of 250 micrograms, a bolus ACTH injection stimulates adrenal steroid secretion as effectively as a 2-h continuous ACTH infusion.
We studied a thiamine-dependent enzyme, transketolase, from fibroblasts of a diabetic patient who developed Wernicke's encephalopathy when treated with tolazamide, in order to delineate if this patient also had transketolase abnormality [high Km for thiamine pyrophosphate (TPP)], as previously reported in postalcoholic Wernicke-Korsakoff syndrome. In addition to this patient, we also studied this enzyme from three diabetic kindreds without any history of Wernicke's encephalopathy and from four normal controls. We found that the above-mentioned patient and one of the diabetic kindreds with no history of Wernicke's encephalopathy had abnormal transketolase as determined by its Km for TPP. These data suggest a similarity between postalcoholic Wernicke-Korsakoff syndrome and the patient with tolazamide-induced Wernicke's encephalopathy from the standpoint of transketolase abnormality.
While it is generally accepted that GnRH stimulates release of pituitary gonadotropins, it is not clear what regulates synthesis. The orchiectomized immature rat, with sustained high plasma levels of LH and FSH, provides an opportunity to study how gonadotropin biosynthesis responds to loss of the gonad. We have measured plasma and pituitary LH and FSH in castrate and sham operated rats after orchiectomy at 15, 30, 45, and 60 days of age. Plasma FSH and LH concentrations by RIA were markedly elevated in castrates within one to three days after castration, and they remained elevated in all groups. By contrast, pituitary content measurements revealed differences between the two gonadotropins: while LH content in castrates consistently exceeded that in controls, FSH content in castrates was lower. Pituitary LH excess was evident by seven to ten days after castration. The pituitary FSH deficit in younger animals was similarly apparent by seven to ten days. In the older groups, however, FSH content decreased as early as three days, but returned toward normal by 21 days. In orchiectomized young rats, pituitary LH is elevated, but FSH content is depressed. This discrepancy is delayed, but more marked, in younger rats. In view of sustained high plasma levels after castration, our findings imply differential regulation of synthesis, processing, or storage of the two gonadotropins.
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