-
Molecular and Cellular Endocrinology Mar 2018In anterior pituitary endocrine cells, large (BK), small (SK) and intermediate (IK) conductance calcium activated potassium channels are key determinants in shaping... (Review)
Review
In anterior pituitary endocrine cells, large (BK), small (SK) and intermediate (IK) conductance calcium activated potassium channels are key determinants in shaping cellular excitability in a cell type- and context-specific manner. Indeed, these channels are targeted by multiple signaling pathways that stimulate or inhibit cellular excitability. BK channels can, paradoxically, both promote electrical bursting as well as terminate bursting and spiking dependent upon intrinsic BK channel properties and proximity to voltage gated calcium channels in somatotrophs, lactotrophs and corticotrophs. In contrast, SK channels are predominantly activated by calcium released from intracellular IP3-sensitive calcium stores and mediate membrane hyperpolarization in cells including gonadotrophs and corticotrophs. IK channels are predominantly expressed in corticotrophs where they limit membrane excitability. A major challenge for the future is to determine the cell-type specific molecular composition of calcium-activated potassium channels and how they control anterior pituitary hormone secretion as well as other calcium-dependent processes.
Topics: Animals; Hormones; Humans; Large-Conductance Calcium-Activated Potassium Channels; Models, Biological; Pituitary Hormones, Anterior; Sex Characteristics
PubMed: 28596131
DOI: 10.1016/j.mce.2017.06.003 -
Journal of Cellular and Molecular... Dec 2020Cranial radiotherapy induces endocrine disorders and reproductive abnormalities, particularly in long-term female cancer survivors, and this might in part be caused by...
Cranial radiotherapy induces endocrine disorders and reproductive abnormalities, particularly in long-term female cancer survivors, and this might in part be caused by injury to the pituitary gland, but the underlying mechanisms are unknown. The aim of this study was to investigate the influence of cranial irradiation on the pituitary gland and related endocrine function. Female Wistar rat pups on postnatal day 11 were subjected to a single dose of 6 Gy whole-head irradiation, and hormone levels and organ structure in the reproductive system were examined at 20 weeks after irradiation. We found that brain irradiation reduced cell proliferation and induced persistent inflammation in the pituitary gland. The whole transcriptome analysis of the pituitary gland revealed that apoptosis and inflammation-related pathways were up-regulated after irradiation. In addition, irradiation led to significantly decreased levels of the pituitary hormones, growth hormone, adrenocorticotropic hormone, thyroid-stimulating hormone and the reproductive hormones testosterone and progesterone. To conclude, brain radiation induces reduction of pituitary and reproduction-related hormone secretion, this may due to reduced cell proliferation and increased pituitary inflammation after irradiation. Our results thus provide additional insight into the molecular mechanisms underlying complications after head irradiation and contribute to the discovery of preventive and therapeutic strategies related to brain injury following irradiation.
Topics: Adrenocorticotropic Hormone; Animals; Biomarkers; Cell Proliferation; Computational Biology; Cranial Irradiation; Disease Models, Animal; Estrous Cycle; Female; Gene Expression Profiling; Gene Expression Regulation; Hypopituitarism; Immunohistochemistry; Pituitary Gland; Pituitary Hormones; Radiation Injuries; Rats; Signal Transduction; Transcriptome; Tumor Suppressor Protein p53
PubMed: 33174363
DOI: 10.1111/jcmm.16086 -
Scientific Reports Nov 2023Omentin-1 (OMNT1) is an adipokine involved in the regulation of energy metabolism, insulin sensitivity, and reproduction. The present study was the first to investigate...
Omentin-1 (OMNT1) is an adipokine involved in the regulation of energy metabolism, insulin sensitivity, and reproduction. The present study was the first to investigate the plasma levels and expression of OMNT1 in the anterior pituitary (AP) gland on days 2-3, 10-12, 14-16, and 17-19 of the estrous cycle of normal-weight Large White (LW) and fat Meishan (MS) pigs. Next, we determined the effect of GnRH, LH, and FSH on the OMNT1 levels in cultured AP cells. The gene and protein expression of OMNT1 in AP fluctuated during the estrous cycle, with a higher expression in MS than in LW (except on days 10-12). However, plasma levels of OMNT1 were higher in LW than in MS. OMNT1 was localized in somatotrophs, lactotrophs, thyrotrophs, and gonadotrophs. In LW pituitary cells, GnRH and gonadotropins stimulated OMNT1 protein expression (except FSH on days 14-16) and had no effect on OMNT1 levels in the culture medium. In MS pituitary cells, we observed that GnRH and LH increased while FSH decreased OMNT1 protein expression. These findings showed OMNT1 expression and regulation in the porcine AP and suggested that OMNT1 could be a new player modifying the pituitary functions.
Topics: Animals; Swine; Gonadotropin-Releasing Hormone; Luteinizing Hormone; Follicle Stimulating Hormone; Gonadotropins; Pituitary Gland, Anterior; Pituitary Gland; Pituitary Hormones, Anterior
PubMed: 37935840
DOI: 10.1038/s41598-023-46742-4 -
The Canadian Veterinary Journal = La... Mar 2023In humans, post-traumatic hypopituitarism (PTHP) is a common complication of traumatic brain injury, with the most frequently reported hormonal deficiencies resulting in...
In humans, post-traumatic hypopituitarism (PTHP) is a common complication of traumatic brain injury, with the most frequently reported hormonal deficiencies resulting in hyposomatotropism and hypogonadism, followed by hypothyroidism, hypocortisolism, and central diabetes insipidus. To date, PTHP has rarely been reported in cats, and the reported cases often describe a single hormone deficiency. This report details an approximately 7-month-old cat with a history of suspected traumatic brain injury at 5 wk of age, that presented with growth retardation (1.53 kg) and polyuria-polydipsia. Thyroid panel, thyrotropin-releasing hormone stimulation test, thyroid scan with Technetium-99, repeat measurement of serum IGF-1, resting cortisol, endogenous ACTH concentration, and ACTH stimulation testing were performed. The cat was diagnosed with presumptive PTHP leading to hyposomatotropism, hypothyroidism, central diabetes insipidus, and hypogonadism. In this case, treatment of the hypothyroidism and central diabetes insipidus were successful. Hyposomatotropism and hypogonadism were not treated. Although reported feline PTHP cases have described a single hormone deficiency, this report details a cat with presumptive PTHP leading to hyposomatotropism, hypothyroidism, central diabetes insipidus, and hypogonadism. Attention should be paid to the potential for the development of PTHP in cats secondary to traumatic brain injury. Key clinical message: Post-traumatic hypopituitarism in cats can lead to multiple hormone deficiencies, leading to hyposomatotropism, hypothyroidism, central diabetes insipidus, and hypogonadism.
Topics: Animals; Cats; Female; Humans; Adrenocorticotropic Hormone; Brain Injuries, Traumatic; Cat Diseases; Diabetes Insipidus, Neurogenic; Hypogonadism; Hypopituitarism; Hypothyroidism; Pituitary Hormones
PubMed: 36874542
DOI: No ID Found -
Cells Dec 2023Corticotropin-releasing hormone (CRH) is known for its crucial role in the stress response system, which could induce pituitary adrenocorticotropic hormone (ACTH)...
Corticotropin-releasing hormone (CRH) is known for its crucial role in the stress response system, which could induce pituitary adrenocorticotropic hormone (ACTH) secretion to promote glucocorticoid release in the adrenal gland. However, little is known about other pituitary actions of CRH in teleosts. Somatolactin is a fish-specific hormone released from the neurointermediate lobe (NIL) of the posterior pituitary. A previous study has reported that ACTH was also located in the pituitary NIL region. Interestingly, our present study found that CRH could significantly induce two somatolactin isoforms' (SLα and SLβ) secretion and synthesis in primary cultured grass carp pituitary cells. Pharmacological analysis further demonstrated that CRH-induced pituitary somatolactin expression was mediated by the AC/cAMP/PKA, PLC/IP3/PKC, and Ca/CaM/CaMK-II pathways. Finally, transcriptomic analysis showed that both SLα and SLβ should play an important role in the regulation of lipid metabolism in primary cultured hepatocytes. These results indicate that CRH is a novel stimulator of somatolactins in teleost pituitary cells, and somatolactins may participate in the stress response by regulating energy metabolism.
Topics: Animals; Corticotropin-Releasing Hormone; Pituitary Hormones; Signal Transduction; Fish Proteins; Glycoproteins; Adrenocorticotropic Hormone
PubMed: 38132090
DOI: 10.3390/cells12242770 -
Journal of Medical Case Reports Jul 2021Plurihormonal pituitary adenomas are a unique type of pituitary adenomas that secrete two or more pituitary hormones normally associated with separate cell types that...
BACKGROUND
Plurihormonal pituitary adenomas are a unique type of pituitary adenomas that secrete two or more pituitary hormones normally associated with separate cell types that have different immunocytochemical and ultrastructural features. Although they represent 10-15% of all pituitary tumors, only a small fraction of plurihormonal pituitary adenomas clinically secrete multiple hormones. The most common hormone combinations secreted by plurihormonal pituitary adenomas are growth hormone, prolactin, and one or more glycoprotein hormones. The most common hormonal symptom is acromegaly (50%). The aim of this case report is to bring awareness about this rare type of pituitary adenomas and to describe the unique presentation of our patient, even though plurihormonal pituitary adenomas are known mostly as a clinically silent tumors.
CASE PRESENTATION
Herein, we describe an unusual case of plurihormonal pituitary adenoma with triple-positive staining for adrenocorticotropic hormone, growth hormone, and prolactin. The patient is a 65-year-old Egyptian woman who presented with mass effect symptoms of the pituitary tumor, which primarily manifested as severe headache and visual field defects. She also presented with some cushingoid features, and further analysis confirmed Cushing's disease; slightly high prolactin and normal growth hormone levels were observed. She underwent transsphenoidal surgery and has been in remission thus far. Only a few cases have been reported in the literature, but none has exhibited silent acromegaly or mass effect symptoms as the initial presentation.
CONCLUSION
This case highlights an unusual plurihormonal pituitary adenoma case with a rare combination of secreted hormones; mass effect symptoms were dominant, as were uncommon visual field defects. Our case further proves that immunohistochemical analyses of all pituitary hormones are needed to ensure correct diagnosis and to alert clinicians to the need for more rigorous follow-up due to the higher morbidity of these patients. Our case report approval number Federal Wide Assurance NIH, USA is FWA00018774 IRB registration number with OHRP/NIH is IRB00010471.
Topics: Adenoma; Adrenocorticotropic Hormone; Aged; Female; Growth Hormone; Humans; Pituitary Neoplasms; Prolactin
PubMed: 34321093
DOI: 10.1186/s13256-021-02948-6 -
Critical Care Medicine Nov 2013Sepsis is a common, lethal poorly understood disorder affecting nearly a million Americans annually. The syndrome is characterized by altered cardiodynamics,...
OBJECTIVES
Sepsis is a common, lethal poorly understood disorder affecting nearly a million Americans annually. The syndrome is characterized by altered cardiodynamics, respiration, metabolism, pituitary function, arousal, and impaired interaction among organ systems. The immunologic and endocrine systems, which are in part responsible for organ-organ communication, have been studied extensively in sepsis. However, little is known about sepsis-induced changes in central nervous system activity.
HYPOTHESIS
A defect in hypothalamic neurons secreting the neurotransmitter orexin modulates physiologic derangements in sepsis.
DESIGN
Animal study.
SETTING
University Research Laboratory.
INTERVENTIONS
Male C57Bl6 mice were made septic using cecal ligation and puncture. Data were collected 24 or 48 hours later, blood was collected, animals were killed, and brain tissue was harvested, fixed, and sectioned. Hypothalamic sections were subjected to immunohistochemistry using antibodies to orexin and c-Fos, a marker of neuronal activity. In a separate cohort of mice, cannulas were placed in the right lateral cerebral ventricle. Cecal ligation and puncture was performed 1 week later. At 24 or 48 hours post-cecal ligation and puncture, vital signs were measured, and1 µL of saline with or without 3 nmol orexin-A was infused. Vital signs were repeated at 25 or 49 hours post-cecal ligation and puncture, blood was collected, animals were killed, and brains were removed, fixed, sectioned, and stained.
MEASUREMENTS AND MAIN RESULTS
Orexinergic activity decreased six-fold following cecal ligation and puncture. This change was associated with decreases in arousal, temperature, and heart and respiratory rates. Levels of selected pituitary hormones increased 24 hours post-cecal ligation and puncture but were significantly lower than baseline at 48 hours. Injection of orexin-A increased vital signs to baseline levels. Hormone levels were unaffected at 25 hours but increased to supranormal levels at 49 hours.
CONCLUSIONS
Sepsis-induced changes in activity, vital signs, and pituitary hormones are modulated by the orexinergic system. This finding implicates central nervous system dysfunction in the pathogenesis of sepsis, suggesting further study of neurological dysfunction to identify novel approaches to management.
Topics: Animals; Body Temperature; Disease Models, Animal; Hemodynamics; Hypothalamus; Intracellular Signaling Peptides and Proteins; Male; Mice; Mice, Inbred C57BL; Neuropeptides; Orexins; Pituitary Hormones; Sepsis; Time Factors
PubMed: 24105451
DOI: 10.1097/CCM.0b013e31828e9843 -
Frontiers in Endocrinology 2021GH deficiency (GHD) in adult patients is a complex condition, mainly due to organic lesion of hypothalamic-pituitary region and often associated with multiple pituitary... (Review)
Review
GH deficiency (GHD) in adult patients is a complex condition, mainly due to organic lesion of hypothalamic-pituitary region and often associated with multiple pituitary hormone deficiencies (MPHD). The relationships between the GH/IGF-I system and other hypothalamic-pituitary axes are complicated and not yet fully clarified. Many reports have shown a bidirectional interplay both at a central and at a peripheral level. Signs and symptoms of other pituitary deficiencies often overlap and confuse with those due to GH deficiency. Furthermore, a condition of untreated GHD may mask concomitant pituitary deficiencies, mainly central hypothyroidism and hypoadrenalism. In this setting, the diagnosis could be delayed and possible only after recombinant human Growth Hormone (rhGH) replacement. Since inappropriate replacement of other pituitary hormones may exacerbate many manifestations of GHD, a correct diagnosis is crucial. This paper will focus on the main studies aimed to clarify the effects of GHD and rhGH replacement on other pituitary axes. Elucidating the possible contexts in which GHD may develop and examining the proposed mechanisms at the basis of interactions between the GH/IGF-I system and other axes, we will focus on the importance of a correct diagnosis to avoid possible pitfalls.
Topics: Hormone Replacement Therapy; Human Growth Hormone; Humans; Hypogonadism; Hypopituitarism
PubMed: 34737721
DOI: 10.3389/fendo.2021.678778 -
Frontiers in Endocrinology 2020Melatonin is a key hormone involved in the photoperiodic signaling pathway. In both teleosts and mammals, melatonin produced in the pineal gland at night is released... (Comparative Study)
Comparative Study Review
Melatonin is a key hormone involved in the photoperiodic signaling pathway. In both teleosts and mammals, melatonin produced in the pineal gland at night is released into the blood and cerebrospinal fluid, providing rhythmic information to the whole organism. Melatonin acts specific receptors, allowing the synchronization of daily and annual physiological rhythms to environmental conditions. The pituitary gland, which produces several hormones involved in a variety of physiological processes such as growth, metabolism, stress and reproduction, is an important target of melatonin. Melatonin modulates pituitary cellular activities, adjusting the synthesis and release of the different pituitary hormones to the functional demands, which changes during the day, seasons and life stages. It is, however, not always clear whether melatonin acts directly or indirectly on the pituitary. Indeed, melatonin also acts both upstream, on brain centers that control the pituitary hormone production and release, as well as downstream, on the tissues targeted by the pituitary hormones, which provide positive and negative feedback to the pituitary gland. In this review, we describe the known pathways through which melatonin modulates anterior pituitary hormonal production, distinguishing indirect effects mediated by brain centers from direct effects on the anterior pituitary. We also highlight similarities and differences between teleosts and mammals, drawing attention to knowledge gaps, and suggesting aims for future research.
Topics: Animals; Antioxidants; Cell Plasticity; Fishes; Mammals; Melatonin; Pituitary Gland, Anterior; Pituitary Hormones, Anterior
PubMed: 33505357
DOI: 10.3389/fendo.2020.605111 -
Experimental Physiology Sep 2003Pituitary hormones have an important role during exercise yet relatively little is known about the stimulus for their release. Body temperature progressively increases... (Clinical Trial)
Clinical Trial Comparative Study
Pituitary hormones have an important role during exercise yet relatively little is known about the stimulus for their release. Body temperature progressively increases during prolonged steady-state exercise in the heat and we have investigated the role that this may play in the release of prolactin, growth hormone and cortisol (as an indicator of adrenocorticotropic hormone) into the circulation. Fit young male subjects exercised at 73% V(O2,max) until volitional fatigue at 20 degrees C and at 35 degrees C (30% relative humidity at both temperatures). Rectal temperature and mean skin temperature were monitored and blood samples analysed for lactate, glucose, cortisol, growth hormone and prolactin concentrations. During the first 20 min, core temperature rose continuously and to a similar extent at both temperatures, while mean skin temperature was approximately 4 degrees C lower during exercise in the cool. Blood glucose concentration was essentially constant throughout the period of exercise while lactate concentration increased in the first 10 min and then remained constant with very similar changes in the two exercise conditions. Prolactin and growth hormone concentrations both increased during the exercise period while the concentration of cortisol declined slightly before rising slightly over the 40 min period. Prolactin release was significantly greater when exercise was carried out in the heat while there was no difference in the release of growth hormone or cortisol in the two conditions. When plotted as a function of rectal temperature, growth hormone concentration showed a linear relationship which was the same at ambient temperatures of 35 degrees C and 20 degrees C. Prolactin concentration had a curvilinear relationship with rectal temperature and this differed markedly at the two ambient temperatures. Cortisol concentration showed no dependence on any measure of body temperature. Our results are consistent with some aspect of body temperature being a stimulus for growth hormone and prolactin secretion; however, the precise mechanism clearly differs between the two hormones and we suggest that skin temperature modulates prolactin release, but does not affect the release of growth hormone.
Topics: Adaptation, Physiological; Adult; Blood Glucose; Body Temperature; Exercise; Exercise Test; Heart Rate; Humans; Lactic Acid; Male; Physical Endurance; Pituitary Hormones; Skin Temperature; Temperature
PubMed: 12955163
DOI: 10.1113/eph8802593