Plasma testosterone and androstenedione after orchiectomy in prostatic adenocarcinoma

Abstract

SUMMARYOrchiectomy is often used in the management of metastatic adenocarcinoma of the prostate, an androgen dependent tumour, since it markedly reduces the concentrations of plasma testosterone (to a mean level of 28 ± 16 (SD) ng/100 ml) and temporarily inhibits the growth of the neoplasma.In some orchiectomized patients, however, the values of plasma testosterone and androstenedione do not drop to these levels, but remain higher, around 137 ± 23 ng/100 ml and 213 ± 39 ng/100 ml respectively.In these patients, treatment with dexamethasone significantly decreased the levels of testosterone and androstenedione to 22 ± 20 ng/100 ml (P<0.0005) and 43 ± 11 ng/100 ml (P<0.0005) respectively.It can therefore be assumed that in orchiectomized patients these compounds are produced in the adrenal cortex, which in some cases is stimulated to produce a larger amount of strong androgens such as testosterone and weaker androgens such as androstenedione.It has also been observed that those patients with an inadequate lowering of plasma testosterone levels after orchiectomy, did not show clinical improvement.Further studies in a larger number of patients are needed in order to support this finding.

Testosterone and Testosterone Precursors in the Spermatic Vein and in the Testicular Tissue of Old Men

“…The testosterone concentrations in the pe ripheral plasma of patients with carcinoma of the prostate reported here are in agreement with the data contained in the literature 0Gandy and Peterson, 1968;Sciarra et al, 1973;Cowley et al, 1976;Harper et al, 1976) and indicate that Leydig cell function in these patients is within the normal range of old men. All the patients with varicocele studied here and those reported on in the literature (Comhaire and Vermeulen, 1975;Swerdloff and Walsh, 1975) had normal plasma testoster one values.…”

Influence of Sex Differences on the Renal Secretion of Organic Anions

“…Sciarra et al (19) reported that castration reduced circulating levels of testosterone by approximately 90%. The decrease in renal secretory ability showed by castrated animals in our study is in agreement with the expected effect from a reduction in testosterone circulating levels.…”

“…This period was chosen because 10 days after castration, the serum concentration of testosterone declines by 90% (19). The experimental procedure followed in the kinetic analysis was the same as described above.…”

Control of Adrenal Androgen Secretion*

“…It appears that they cannot be suppressed below a baseline of approximately 20% of pretreatment A and DHA concentrations (12,16). This residual baseline could result either from direct adrenal secretion, desulfuration of a chronic non-ACTH dependent pool of DHAS, or both.…”

“…These data are summarized in Table 2. Sciarra et al (12) administered 2 mg dexamethasone orally to 10 men 2 months after orchiectomy for prostatic carcinoma. Their serum A decreased 80% from 2.1 ng/ml to 0.43 ng/ml as determined by competitive protein-binding assay.…”