The effects of adrenergic receptor agonists on GH secretion were studied in adult, male rats pretreated with reserpine and somatostatin antiserum. Frequent blood samples were obtained from intra-aortic cannulae. Plasma GH was determined by radioimmunoassay. Reserpine (10 mg/kg i.p.) caused a complete suppression of the normal, pulsatile secretion of GH in all animals. Administration of somatostatin antiserum resulted in rapid elevations of plasma GH in reserpine-pretreated rats with peak levels at 30 min. GH levels then fell but remained slightly elevated for the duration of the sampling period (8 h). Apomorphine (0.5 mg/kg i.p.) had no effect on plasma GH levels, whereas clonidine (0.5 mg/kg i.p.) induced release of GH in both antiserum treated and control rats. The results indicate that the alpha-adrenergic influence on the secretion of GH is mediated not by inhibition of somatostatin release but rather by effects on the release of a GHRF.
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Arch Insect Biochem Physiol
January 2025
State Key Laboratory of Agricultural and Forestry Biosecurity, Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests/State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
The activin cascade is activated when a pair of extracellular ligand (Myoglianin, Myo; Activin β, Actβ; Dawdle, Daw) binds to two pairs of transforming growth factor β (TGF) serine-threonine receptor kinases, TGF-β type I (Baboon, Babo) and II receptors. However, the roles of activin way have not well been explored in non-Drosophilid insects. In the present paper, we compared the functions of Activin β (Actβ) ligand and receptor isoform BaboB in post-embryonic development in a defoliating ladybird Henosepilachna vigintioctopunctata.
View Article and Find Full Text PDFAndrology
January 2025
Section of Endocrinology and Investigative Medicine, Imperial College London, London, UK.
The hypothalamic-pituitary-gonadal axis is regulated by the gonadotropin-releasing hormone pulse generator in the hypothalamus. This is comprised of neurons that secrete kisspeptin in a pulsatile manner to stimulate the release of GnRH, and, in turn, downstream gonadotropins from the pituitary gland, and subsequently sex steroids and gametogenesis from the gonads. Many reproductive disorders in both males and females are characterized by hypothalamic dysfunction, including functional disorders (such as age-related hypogonadism, obesity-related secondary hypogonadism, hyperprolactinemia, functional hypothalamic amenorrhea and polycystic ovary syndrome), structural pathologies (such as craniopharyngiomas or radiation or surgery-related hypothalamic dysfunction), and pubertal disorders (constitutional delay of growth and puberty and congenital hypogonadotropic hypogonadism).
View Article and Find Full Text PDFRev Neurosci
January 2025
School of Medical Sciences, Henan University of Chinese Medicine, Zhengzhou 450046, Henan Province, China.
Cholecystokinin (CCK) is a major neuropeptide in the brain that functions as a neurotransmitter, hormone, and growth factor. The peptide and its receptors are widely expressed in the brain. CCK signaling modulates synaptic plasticity and can improve or impair memory formation, depending on the brain areas studies and the receptor subtype activated.
View Article and Find Full Text PDFFront Cardiovasc Med
January 2025
Department of Pediatric Endocrinology and Rheumatology, Institute of Pediatrics, Poznan University of Medical Sciences, Poznan, Poland.
Background: Loeys-Dietz syndrome (LDS) is a clinically and genetically heterogeneous, autosomal dominant aortic aneurysm syndrome with widespread systemic involvement. We present the case of a 16.5-year-old girl with LDS type 2 (LDS2) caused by a heterozygous pathogenic variant, c.
View Article and Find Full Text PDFUnlabelled: Growth hormone (GH) plays a crucial role in various physiological functions, with its secretion tightly regulated by complex endocrine mechanisms. Pathological conditions such as acromegaly or pituitary tumors result in elevated circulating GH levels, which have been implicated in a spectrum of metabolic disorders, potentially by regulating liver metabolism. In this study, we focused on the liver, a key organ in metabolic regulation and a primary target of GH, to investigate the impact of high circulating GH on liver metabolism.
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