Corticotrophin releasing hormone (CRH_1–41) stimulates the secretion of adrenocorticotrophin, vasopressin and oxytocin but not adrenocorticotrophin precursors: evidence from petrosal sinus sampling in man

Abstract

To examine the relationship between corticotrophin releasing hormone (CRH), arginine vasopressin (AVP) and oxytocin (OXT) we have studied the responses of adenohypophyseal and neurohypophyseal hormones to CRH in eight patients (age 26-64 years, six female) with suspected pituitary-dependent Cushing's syndrome during bilateral, simultaneous inferior petrosal sinus catheterization. Blood samples were taken from both petrosal sinuses and a peripheral vein before, and at 5-min intervals for 15 min after, an intravenous injection of 100 micrograms human CRH1-41. CRH increased sinus AVP concentrations in all eight patients and OXT concentrations in four of five patients studied. Although AVP concentrations often increased in both sinuses, the side of maximal AVP rise was termed side(max-AVP). CRH did not affect peripheral or petrosal sinus mean concentrations of LH, FSH, GH or TSH. While there was no change in mean peripheral concentrations of AVP, OXT, ACTH, ACTH precursors or prolactin after CRH, sinus concentrations of OXT, ACTH and prolactin on side(max-AVP) were markedly elevated over contralateral values. CRH did not increase mean sinus concentrations of ACTH precursors. In seven patients with either no radiological abnormality or the pituitary fossa or a small adenoma the mean ACTH precursor/ACTH ratio in blood sampled from all sites was 2.1 +/- 0.16 (mean +/- SEM, n = 50). In a patient with a large, locally invasive tumour the mean ACTH precursor/ACTH molar ratio was 32.1 +/- 1.3 (n = 12; P less than 0.001), suggesting that alterations in this molar ratio may reflect the biological properties of the tumour. The source of CRH-stimulatable AVP and OXT remains uncertain.(ABSTRACT TRUNCATED AT 250 WORDS)

Corticotropin Releasing Hormone Administration Increases Alpha-Melanocyte-Stimulating Hormone Levels in the Inferior Petrosal Sinuses in a Subset of Patients with Cushing’s Disease

“…This data is in agreement with a previous reported evalu ating the a-MSH response to CRH in the peripheral blood [26]. Similarly, Nussey et al [40] were unable to find any change of ACTH precursors during CRH stimulation in the inferior petrosal sinuses. It should be considered, how ever, that in the above-mentioned paper [40] a small series of patients, namely 8, with Cushing's disease are studied.…”

“…Similarly, Nussey et al [40] were unable to find any change of ACTH precursors during CRH stimulation in the inferior petrosal sinuses. It should be considered, how ever, that in the above-mentioned paper [40] a small series of patients, namely 8, with Cushing's disease are studied. Because in our series only 23.3% of the patients had a significant increase of a-MSH during CRH chal lenge, it is quite possible that when a small number of cases is studied, this finding may go unnoticed.…”

Inferior petrosal sinus sampling in healthy subjects reveals a unilateral corticotropin-releasing hormone-induced arginine vasopressin release associated with ipsilateral adrenocorticotropin secretion.

“…Recently, Nussey et al reported lateralized AVP and OT secretion into the IPS of patients with Cushing disease after administration of CRH, without a concomitant change in peripheral AVP or OT levels (31). However, this finding could have been caused by the presence of the pituitary adenoma and might not have represented normal physiology.…”

Sequence of pituitary–adrenal cortical hormone responses to low-dose physostigmine administration in young adult women and men

“…Nussey et al (1991) measured both hormones in the inferior petrosal sinus and peripheral venous samples following CRH administration in six women and two men with suspected Cushing's syndrome. AVP and ACTH were both increased in the first 5-min petrosal sinus sample, after which AVP declined and ACTH continued to increase.…”