کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2800960 | 1156135 | 2011 | 9 صفحه PDF | دانلود رایگان |
PACAP (pituitary adenylate cyclase activating polypeptide) is widely distributed neuropeptide acting via three subtypes of receptors, PAC1, VPAC1 and VPAC2. Here we examined the localisation and nature of PACAP-immunoreactive nerves in the rat thyroid and parathyroid glands and defined the distribution of PAC1, VPAC1 and VPAC2 receptor mRNA’s. In the parathyroid gland a large number of nerve fibres displaying PACAP-immunoreactivity were distributed beneath the capsule, around blood vessels and close to glandular cells. Most of the PACAP-nerves were sensory, since they co-stored CGRP (calcitonin-gene-related peptide) and were sensitive to capsaicin-treatment. mRNA’s for PAC1 and VPAC2 receptors occurred in the parathyroid gland, mainly located in the glandular cells. In the thyroid gland PACAP-immunoreactive nerve fibres were associated with blood vessels, thyroid follicles and parafollicular C-cells. A high degree of co-existence between PACAP and VIP (vasoactive intestinal polypeptide) was observed in the intrathyroid nerve fibres and cell bodies of the thyroid ganglion indicating a common origin for the two peptides. A minor population of PACAP-immunoreactive nerve fibres with relation to blood vessels co-stored NPY (neuropeptide Y), whereas only a few fibres co-stored CGRP. PAC1 and VPAC1 receptor mRNA’s occurred in follicular cells and blood vessels, whereas the expression of the VPAC2 receptor was low. The findings suggest that PACAP plays a role in the regulation of parathyroid and thyroid blood flow and hormone secretion.
Research highlights
► PACAP-immunoreactive nerve fibres innervate the rat parathyroid and thyroid glands.
► The nerve fibres are associated with blood vessels and endocrine cells.
► PACAP-receptors (PAC1 and VPAC1) are present in the innervated structures.
Journal: General and Comparative Endocrinology - Volume 171, Issue 1, 1 March 2011, Pages 105–113