Kinetics of testosterone, dihydrotestosterone (DHT) and 5alpha-androstane-3alpha,17beta-diol (3alpha-diol) were studied in 7 elderly healthy men (ages 61 to 80 years) with benign prostatic hyperplasia (BPH). Clearance rates were determined by the constant infusion technique with labeled testosterone and DHT. Metabolic clearance rate (MCR), conversion ratio (CR), the transfer constants (rho) and production rates (PB) were calculated. Plasma androgens were measured by specific radioimmunoassay. Plasma testosterone was 516 +/- 314 (SD) ng/dl, plasma DHT was 74.6 +/- 19.6 (SD) ng/dl and plasma 3alpha-diol was 16.4 +/- 4.1 (SD) ng/dl. An elevated DHT level in elderly men with BPH wasconfirmed. MCRT was 620 +/- 65 (SD) liter/day and MCRDHT was 393 +/- 50 (SD) liter/day. Both MCRT and MCRDHT in elderly men were significantly lower than in young men. PBT was 3.2 +/- 2.1 (SD) mg/day and PBDHT was 291 +/- 87 (SD)migrogram/day. PBDHT was the same in elderly and young men. DHT production is maintained in elderly men despite reduction of testosterone production. From the data, it was claculated that in contrast to young men where greater than 80% of blood DHT is from secreted testosterone, over 50% in elderly men is derived from secretion or production of DHT by the testis or even more likely the prostate.
The splanchnic extraction and interconversion of testosterone and dihydrotestosterone (DHT) were studied in 7 healthy men (ages 29-46 years) undergoing cardiac catheterization. During a constant infusion of [1,2-3H]testosterone and [4-14C]DHT, the arterial and hepatic vein blood samples were taken and radioactive and non-radioactive testosterone and DHT were determined. Metabolic clearance rate (MCR), splanchnic extraction (SE), splanchnic clearance (SC), extrasplanchnic clearance (ESC), transfer constant in blood (T-DHT rhoBB) and transfer constant across the liver (T-DHT rhoSB) were calculated. The MCRT was 952 +- 172 (mean +- SD) 1/day and MCRDHT was 764 +/- 67 1/day in agreement with data from non-catheterized subjects. SET was 68.8 +/- 7.1% (mean +/- SD) and SEDHT was 37.6 +/- 5.9%. SET was significantly greater than SEDHT (P less than 0.001). The calculated SCT and ESCT were 638 +/- 112 (mean +/- SD) 1/day and 314 +/- 190 1/day, respectively. SCDHT and ESCDHT were 343 +/- 95 (mean +/-SD) 1/day and 421 +/-105 1/day, suggesting that a major fraction of testosterone is metabolized in the splanchnic organs and a higher fraction of DHT is metabolized in extrasplanchnic organs. In the interconversion study, overall conversion of testosterone to DHT in blood (T-DHT rhoBB) was 4.0 +/- 0.6% (mean +/- SD). No evidence for a net appearance of DHT by either mass or specific activity analysis in hepatic vein blood was observed in any infusion leading to the conclusion that the overall contribution of testosterone to circulating DHT from the liver (T-DHTrhoSB) was undetectable. This work indicates that conversion of testosterone to DHT occurs entirely in extrasplanchnic tissue in man.
The incidence of macrosomic infants weighing 5,000 g or more is rare. We experienced a case of nondiabetic macrosomia, in which the fetus weighed more than 5,000 g. The newborn was diagnosed as having Simpson-Golabi-Behmel syndrome. We discuss antenatal ultrasonographic findings in the case.
Tritiated testosterone and [14C]dihydrotestosterone (DHT) were administered by constant iv infusion into five young and five elderly men undergoing diagnostic cardiac catheterization. The radioactivity concentrations of free and conjugated DHT in arterial and hepatic vein blood samples were then determined. The analysis of the 3H:14C ratio of free DHT in arterial and hepatic vein blood showed that in both groups, the 3H:14C ratio of free DHT was the same in arterial and hepatic vein blood, indicating that splanchnic tissue is not the source of blood DHT from testosterone. This is in agreement with data that the transfer constant across the liver ([rho]T-DHT SD) was undetectable. In both young and elderly men, a significant increase of the 3H concentration of DHT glucuronide in hepatic vein blood was observed, indicating that the splanchnic compartment could be the site of production of DHT glucuronide. The 3H:14C ratio of DHT glucuronide was much higher than that of free DHT in both groups, suggesting that DHT glucuronide is derived from the blood testosterone pool, and most of the DHT from testosterone seems to be conjugated before mixing with blood DHT. This study indicates that a large fraction of DHT produced in the liver from testosterone is efficiently conjugated or further metabolized, and this results in the lack of splanchnic production of free DHT in men.
Intrauterine growth-retardation, represented by abnormal fetal blood redistribution was associated with adverse perinatal outcome, but the influence was not found at the first year of life.
Abstract.A 40-year-old woman with adrenal insufficiency was clinically diagnosed and examined with human corticotropin releasing hormone (CRH). This patient with secondary hypo-adrenalism has shown a normal serum cortisol response to exogenous ACTH administration and has been examined with CRH, lysine-vasopressin (LVP) and insulin tolerance test (ITT), respectively. Success in secreting ACTH in response to both CRH and LVP tests, but not ITT, suggests that this disorder was possibly due to a hypothalamic CRH deficiency rather than pituitary corticotroph dysfunction.A combination of the CRH test and ITT has come to play an increasingly significant role in the diagnosis and differential diagnosis of isolated ACTH deficiency syndrome.
This is the first autopsy case of male 17 alpha-hydroxylase deficiency with malignant hypertension. The subject had hypertension, hypokalemic alkalosis, and pseudohermaphroditism. At age 21, 17 alpha-hydroxylase deficiency was diagnosed by low urinary excretion of 17-hydroxysteroids, low secretion rate of cortisol, and low plasma testosterone level in association with high urinary excretion of pregnanediol and high plasma progesterone and corticosterone. Urinary excretion of aldosterone and PRA were suppressed, and plasma ACTH was elevated. Hypertension and hypokalemic alkalosis were normalized with dexamethasone therapy. After missing 5 yr of follow-up, malignant hypertension developed, and PRA and aldosterone were elevated. Histological examination revealed some characteristic arteriolar lesions as in malignant nephrosclerosis. Juxtaglomerular hyperplasia and an increase of renin granules were observed, which reflected high PRA. Abnormal histological findings of endocrine organs were observed in the breast, the pituitary gland, the adrenal glands, and the testis.
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