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Abstract.

Adipocytes from streptozotocin-diabetic rats showed a markedly reduced lipolytic response to glucagon concomitant with a 90% or greater decrease in the number of glucagon receptors per cell. In contrast, β-adrenergic receptors assessed by [³H]dihydroalprenolol binding and lipolysis stimulated by isoproterenol, dibutyryl 3′5′-cyclic AMP and 3-isobutyl-1-methylxanthine were reduced by only 10–25% in diabetic rats compared with controls. Furthermore, quantitative analysis of the relationship between the amount of cell-bound glucagon and the hormone-stimulated lipolysis revealed that the function of the remaining 10% of glucagon receptors remained intact in cells from diabetic animals. These findings suggest that the lipolytic cascades, including β-adrenergic receptors, in adipocytes are not greatly impaired by diabetes, and therefore, the unresponsiveness of these cells to glucagon is mostly due to a marked reduction in the number of glucagon receptors, probably as a result of a down-regulation by postprandial hyperglucagonemia.

Abstract. A pilot neonatal mass-screening for congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) was performed in the western region of Shizuoka Prefecture, Japan, using a simplified radioimmunoassay method for 'Disc-17-hydroxyprogesterone (17-OHP)' determination. The results obtained during a 30-month period indicated that 3 infants out of the 34314 neonates examined were proved to have 21-OHD, and the incidence of homozygotes and heterozygotes were estimated to be 1:11438 and 1:54, respectively. At the time of recall, the concentrations of plasma 17-OHP and 21-deoxycortisol and their urine metabolites as well as plasma sodium levels were quite applicable to diagnosis, while the clinical signs that may be manifest in 21-OHD were of little value in this connection. Prematurity and perinatal complications of neonates tended to give false-positive results, being secondary to the function of the residual foetal adrenal cortex and non-specific stimulatory effects of various stresses.

Despite several technical and practical problems to be solved, the present study demonstrated the importance and validity of a neonatal mass-screening program for CAH.