Changes in growth hormone secretion and leptin receptor mRNA expression under the influence of leptin and adrenocorticotropin in pituitary cells of early weaned ewe lambs.

Changes in growth hormone secretion and leptin receptor mRNA expression under the influence of leptin and adrenocorticotropin in pituitary cells of early weaned ewe lambs. J Physiol Pharmacol. 2019 Aug;70(4): Authors: Kosior-Korzecka U, Wojcik M, Longo V, Puzio I, Nowakiewicz A, Patkowski K, Gregula-Kania M Abstract Early weaning of ewe lambs strongly stimulates the hypothalamic-pituitary-adrenal axis and is associated with suppressed growth rate despite the increased food intake. At the same time, plasma leptin concentration increases only slightly or undetectably. To better understand this atypical interdependence among somatic stress, leptin, and lamb growth rate, we analyzed impact of leptin and/or adrenocorticotropic hormone (ACTH) on growth hormone (GH) secretion as well as the effect of ACTH on mRNA expression of two splice variants of leptin receptor (LEPRa, LEPRb) in pituitary cells isolated from early weaned ewe lambs. The GH secretion under the influence of leptin and/or ACTH depended on the timing of exposure and hormone concentration. After 6 - 30 h, GH secretion increased under 10-11 - 10-8 M leptin (P ≤ 0.05). However, after 24 - 30 h, GH secretion significantly increased only in cells exposed to both leptin and ACTH compared to culture with leptin only. Simultaneously, there was a significant (P ≤ 0.05) decrease in leptin receptor mRNA expression under the influence of ACTH at 10-8 - 10-6 M after 12 - 30 and 24 - ...
Source: Journal of Physiology and Pharmacology - Category: Drugs & Pharmacology Tags: J Physiol Pharmacol Source Type: research