Following the discovery of the growth hormone release-inhibiting factor somatostatin from extracts of ovine hypothalamus, an N-terminally extended somatostatin of 28 amino acids has been identified in mammalian tissue. The original peptide, somatostatin-14 (SS14), corresponds to the C-terminus of somatostatin-28 (SS28). Both SS28 and SS14 have biological activity, occur in several rat brain regions, are present in cell bodies and nerve terminals and can be released in vitro upon depolarization in a calcium-dependent manner. Further, high-affinity binding sites were described for SS14, which also bind SS28 (refs 20-23). Recently, a dodecapeptide which corresponds to the N-terminus of somatostatin-28, somatostatin-28(1-12), has been characterized in rat hypothalamus. Radioimmunological and immunohistochemical studies have indicated the presence of SS28(1-12)-like immunoreactivity in several cortical and subcortical regions of the rat brain. This peptide was found to be unevenly distributed with the highest concentration in the hypothalamus, and preferentially localized to dendritic and axonal processes and terminals. These observations suggest that SS28(1-12) may be a neurotransmitter. In this study, we describe a calcium-dependent release of a SS28(1-12)-like peptide from hypothalamic slices in vitro. This finding supports a neurotransmitter function for this peptide.
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http://dx.doi.org/10.1038/301524a0 | DOI Listing |
Alzheimers Dement
December 2024
University of South Carolina School of Medicine, Columbia, SC, USA.
Background: The orexin/hypocretin neuropeptide system, primarily found in the lateral hypothalamus and perifornical region, modulates sleep, wakefulness, appetite, and cognitive function. One region with dense orexinergic projections is the basal forebrain (BF), which is the major source of acetylcholine in the neocortex and limbic structures such as the hippocampus. The basal forebrain cholinergic system mediates cognition and dysfunction is one of the key hallmarks of Alzheimer's disease.
View Article and Find Full Text PDFMetabolism
December 2024
Instituto Maimónides de Investigación Biomédica de Cordoba (IMIBIC), Department of Cell Biology, Physiology and Immunology, University of Cordoba; and Hospital Universitario Reina Sofia, Cordoba, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain. Electronic address:
Female reproduction is highly sensitive to body energy stores; persistent energy deficit, as seen in anorexia or strenuous exercise, is known to suppress ovulation via ill-defined mechanisms. We report herein that hypothalamic SIRT1, a key component of the epigenetic machinery that links nutritional status and puberty onset via modulation of Kiss1, plays a critical role in the control of the preovulatory surge of gonadotropins, i.e.
View Article and Find Full Text PDFNeuropharmacology
December 2024
Department of Experimental Physiology and Pathophysiology, Medical University of Białystok, Ul. Mickiewicza 2A, 15-222, Białystok, Poland.
Although angiotensin 1-7 (Ang 1-7) and its role as a part of the "protective" axis of the renin-angiotensin system are well described in the literature, the mechanisms of its angiotensin II-like pressor and tachycardic effects following its acute central administration are not fully understood. It was the aim of the present study to examine which receptors contribute to the aforementioned cardiovascular effects. Ang 1-7 and antagonists for glutamate, GABA, vasopressin, thromboxane A (TP), α-adrenergic, and P2X purinoceptors or modulators of oxidative stress were injected into the paraventricular nucleus of the hypothalamus (PVN) of urethane-anesthetized male Wistar rats.
View Article and Find Full Text PDFExp Neurol
December 2024
Department of Pediatrics, UH Rainbow Babies & Children's Hospital, Case Western Reserve University School of Medicine, Cleveland, OH, United States of America. Electronic address:
Neonatal sepsis results in significant morbidity and mortality, but early detection is clinically challenging. In a neonatal rat model of endotoxic shock, we characterised unique infrared thermographic (IRT) profiles in skin temperature that could identify risk of later mortality. Ten-day old rats were placed in a thermally stable isolette and IRT images of cranial (T), scapula (T) and rump (T) skin temperature were obtained continuously for 8 h following an intraperitoneal injection of lipopolysaccharide (LPS) or saline.
View Article and Find Full Text PDFJ Nanobiotechnology
December 2024
Key Laboratory of Special Environmental Medicine of Xinjiang, General Hospital of Xinjiang Military Command, No. 359, Youhao North Road, Urumqi, Xinjiang, China.
Objective: This study aims to elucidate the mechanisms by which nanovesicles (NVs) transport curcumin(CUR) across the blood-brain barrier to treat hypothalamic neural damage induced by heat stroke by regulating the expression of poly(c)-binding protein 2 (PCBP2).
Methods: Initially, NVs were prepared from macrophages using a continuous extrusion method. Subsequently, CUR was loaded into NVs using sonication, yielding engineered cell membrane Nanovesicles loaded with curcumin (NVs-CUR), which were characterized and subjected to in vitro and in vivo tracking analysis.
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