Effect of calcitonin on adrenocorticotropic hormone secretion stimulated by corticotropin‐releasing hormone in the hen anterior pituitary

Abstract

The presence of a receptor for calcitonin (CT) and the effect of chicken CT (cCT) on adrenocorticotropic hormone (ACTH) secretion stimulated by rat/human corticotropin-releasing hormone (rhCRH) in the hen anterior pituitary were studied. The specific [(125)I]cCT binding component was present in the plasma membrane of hen anterior pituitary and this binding component had properties of a receptor which has binding specificity to cCT, reversibility, saturable binding, high affinity and limited capacity. When anterior pituitary cells were incubated in vitro, cCT increased the maximal secretion of chicken ACTH stimulated by rhCRH. These results suggest that CT may act directly on the anterior pituitary via its receptor binding and enhances the ACTH secretion by CRH.

Parathyroid hormone-related peptide directly increases adrenocorticotropic hormone secretion from the anterior pituitary in hens

“…Therefore, the binding component for cPTHrP in plasma membrane fractions of the anterior pituitary is likely to be a receptor for cPTHrP. The order of magnitude of K d and B max values was also the same as that of luteinizing hormone-releasing hormone receptor (Kawashima et al, 1992) and calcitonin receptor (Nakayama et al, 2010b) in the hen anterior pituitary.…”

“…Recently, it was reported that calcitonin enhances the secretion of ACTH from the anterior pituitary via its receptor (Nakayama et al, 2010b). However, it has not been reported whether PTHrP is involved in the regulation of ACTH secretion in the anterior pituitary of hens.…”

Calcitonin receptor binding in the hen anterior pituitary during an oviposition cycle

“…Chicken CT (cCT; Bachem AG, Bubendorf, Switzerland) was labeled with 125 I using Iodogen (Takahashi et al . 1993; Nakayama et al . 2010a).…”

“…2008). Recently, it was reported that CT acted directly on the anterior pituitary via its receptor binding and enhanced the amount of adrenocorticotropic hormone (ACTH) secretion stimulated by corticotropin‐releasing hormone (Nakayama et al . 2010a).…”

“…The primary role of CT is to regulate calcium homeostasis (Kenny 1986) with parathyroid hormone (Kenny & Dacke 1974) and vitamin D (Savaram et al 2008). Recently, it was reported that CT acted directly on the anterior pituitary via its receptor binding and enhanced the amount of adrenocorticotropic hormone (ACTH) secretion stimulated by corticotropin-releasing hormone (Nakayama et al 2010a). Adrenocorticotropic hormone is well known to stimulate the corticosterone secretion from the adrenal gland (Carsia & Harvey 2000).…”