Corticotropin-releasing factor ovine (Ovine CRF)

Corticotropin-releasing factor ovine (Ovine CRF) is a corticotropin-releasing factor 1 (CRF1) receptor agonist, a polypeptide composed of 41 amino acids^{[1, 2]}. The mechanism of action of Corticotropin-releasing factor ovine involves binding to the CRH1 receptor in the anterior pituitary gland, activating adenylate cyclase, leading to increased intracellular cAMP levels, which in turn promotes the synthesis and release of adrenocorticotropic hormone (ACTH). ACTH then stimulates the adrenal cortex to produce cortisol^[3]. Corticotropin-releasing factor ovine can be used to help differentiate whether the excessive ACTH secretion in patients with ACTH-dependent Cushing's syndrome originates from the pituitary gland (Cushing's disease) or from ectopic sources (ectopic ACTH syndrome)^[4].

In vivo, intraventricular injection of 10µg of Corticotropin-releasing factor ovine into a buffet-fed rat inhibited food intake over 6h, regardless of the macronutrient composition of the food, with the strongest inhibitory effect on the intake of preferred foods^[5].

References:
[1] Behan D P, De Souza E B, Lowry P J, et al. Corticotropin releasing factor (CRF) binding protein: a novel regulator of CRF and related peptides[J]. Frontiers in neuroendocrinology, 1995, 16(4): 362-382.
[2] Stalla G K, Hartwimmer J, Von Werder K, et al. Ovine (o) and human (h) corticotrophin releasing factor (CRF) in man: CRF-stimulation and CRF-immunoreactivity[J]. European Journal of Endocrinology, 1984, 106(3): 289-297.
[3] Jun-Ping L. Studies of the mechanisms of action of corticotropin-releasing factor (CRF) and arginine vasopressin (AVP) in the ovine anterior pituitary: evidence that CRF and AVP stimulate protein phosphorylation and dephosphorylation[J]. Molecular and cellular endocrinology, 1994, 106(1-2): 57-66.
[4] Elenius H, McGlotten R, Nieman L K. Ovine CRH stimulation and 8 mg dexamethasone suppression tests in 323 patients with ACTH-dependent Cushing's syndrome[J]. The Journal of Clinical Endocrinology & Metabolism, 2024, 109(1): e182-e189.
[5] Zorrilla E P, Reinhardt L E, Valdez G R, et al. Human urocortin 2, a corticotropin-releasing factor (CRF) 2 agonist, and ovine CRF, a CRF1 agonist, differentially alter feeding and motor activity[J]. The Journal of pharmacology and experimental therapeutics, 2004, 310(3): 1027-1034.

Corticotropin-releasing factor ovine (Ovine CRF)是一种促肾上腺皮质激素释放因子1（CRF1）受体激动剂，是一种由41个氨基酸组成的多肽^{[1, 2]}。Corticotropin-releasing factor ovine的作用机制是通过与垂体前叶的CRH1受体结合，激活腺苷酸环化酶，导致细胞内cAMP水平升高，进而促进促肾上腺皮质激素（ACTH）的合成与释放，ACTH随后刺激肾上腺皮质产生皮质醇^[3]。Corticotropin-releasing factor ovine能够用于协助鉴别ACTH依赖性库欣综合征患者的ACTH过度分泌来源是垂体性（库欣病）还是异位性（异位ACTH综合征）^[4]。

在体内，Corticotropin-releasing factor ovine（10µg）通过脑室内注射给药处理喂食自助餐的大鼠，抑制了大鼠6小时的食物摄入量，且与食物的宏量营养素组成无关，对偏好食物的摄入抑制作用最强^[5]。