We report on a case of ectopic Cushing's syndrome due to a thymic carcinoid tumour with periodic hormonogenesis. Periods of hormonal production averaged 27 days. Prior to bilateral adrenalectomy, mean (s.d) values of ACTH and cortisol were 202.1 (50.3) pg/ml and 46 (14.7) micrograms/dl, ACTH rising to 3996 +/- 425 pg/ml (P less than 0.01) and cortisol falling to 6.3 +/- 1.5 micrograms/dl (P less than 0.01) in the immediate postoperative period. During the late postoperative period (2-13 months following surgery) ACTH levels fell to 509.3 (123.8) pg/ml (P less than 0.01), but remaining even higher (P less than 0.01) than before adrenalectomy. The pattern of ACTH in the present case suggests the existence of a negative feedback exerted by the cortisol over tumoral ACTH.

ACTH Syndrome, Ectopic↗

PubMed1986

Interaction of thyrotrophin releasing hormone and the enkephalin analogue DAMME on pituitary hormone secretion.

Because TRH counteracts the inhibitory effect of opiate peptides on LH secretion in cultured cells from normal pituitaries, six normal postmenopausal women were studied to determine whether TRH interacts in vivo with opioid peptides in the regulation of pituitary hormone secretion. At two different times a constant 3 h infusion of either saline or TRH (5 micrograms/min) was initiated. At 60 min a 250 micrograms bolus of the opiate agonist peptide D-Ala2-MePhe4-met-enkephalin-0-ol (DAMME) was injected in one of the two saline and TRH infusion tests. The four treatments, i.e. saline infusion alone, saline infusion with a DAMME bolus, TRH infusion alone; and TRH infusion with DAMME bolus were given at random with an interval of at least 7 d. Blood samples were taken every 15 min during the 3 h study. DAMME induced a significant fall (P less than 0.05) in serum LH (from 35 +/- 8.5 to 18.3 +/- 5.1 mIU/ml) (mean +/- SEM) without significantly affecting FSH levels (from 29 +/- 11.2 to 26.9 +/- 12.4 mIU/ml). These changes were not antagonized by the continuous infusion of TRH. PRL had a monophasic response pattern to continuous isolated TRH infusion; the basal levels increased from 4.2 +/- 1.2 to 24.5 +/- 6.8 ng/ml at 30 min and then slowly decreased with a plateau from 90 min until the end of the study. DAMME administration at 60 min induced a significant second peak of PRL secretion (44 +/- 6.5 ng/ml) 30 min later (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1986