Morphological study of the pituitary gland of the studanese Nile fish Clarias Lazera

C. lazera was studied using some standard techniques employed in the study of vertebrate pituitary. The pituitary gland is attached to the infundibular region of the brain by a cylindrical infundilbular stalk. The gland is composed of two main divisions; the pars glandularis and the pars nervosa. The former is subdivided into an anterior, middle and posterior glandular regions. The anterior glandular region is composed mostly of clusters of acidophils which surround blood capillaries, giving the region a follicular appearance. The middle region is composed of basophils, acidophils and chromophobes. The distribution of the three types of cells has no definite pattern. The basophils are characterized by possessing colloidal globules, and therefore such basophils are described as globular basophils. The posterior region is formed mostly of dull acidophils, with few interspersed dull faint basophils. The two types of cells are scattered singly or in groups arround the branches of the pars nervosa. The pars nervosa, which is the continuation of the infundibular stalk, form a central core around which the three glandular regions of the pituitary gland are arranged. The processes of the pars nervosa are elaborate, with a fanning root – like nature, in the posterior glandular region and scanty in both the anterior and middle glandular regions. The pars nervosa appears as a fibrous tissue with scattered nuclei belonging to neuroglia cells. It is characterized by the colloidal Herring materials, basophil and acidophilic glandular cells. Infundilbular stalk, which link the floor of hypothalamus and the terminal zone of the anterior glandular region was found to be a thin lamina of nervious tissue with a layer of epindymal cell lining the third ventricle. The middle glandular region was found to consist of three chromophils cells, only one type of acidophil was identified. It took both OG and erythrosin. The other two types were found to be basophilic and they were designated as type 2 and type 3. Basophils type 3 were PAS, AF positive but AB negative. The pars nervosa was found to be small, and contained more stainable neuro-secretory materials.

Postnatal developmental trajectory of sex-biased gene expression in the mouse pituitary gland

The pituitary gland controls sexually dimorphic processes such as growth, pubertal onset, and lactation. However, the mechanisms underlying sex biases in pituitary gene regulation are not fully understood. To capture pituitary gene regulation dynamics during postnatal development, we ascertained gene and miRNA expression across five postnatal days that span the pubertal transition in mice. Using three prime untranslated region and small RNA sequencing, we observed over 900 instances of sex-biased gene expression, including 18 genes that were putative targets of 5 sex-biased miRNAs. In addition, by combining bulk RNA-seq with scRNA-seq pituitary data, we obtained evidence that cell-type proportion sex differences exist prior to puberty and contribute substantially to the observed sex-biased gene expression post-puberty. This work provides a resource for postnatal mouse pituitary gene regulation and highlights the importance of sex-biases in both cell-type composition and gene regulation when understanding the sexually dimorphic processes regulated by the pituitary gland.

Contact endoscopy as a novel technique for intra-operative identification of normal pituitary gland and adenoma

Intraoperative distinction of pituitary adenoma from normal gland is critical in maximizing tumor resection without compromising pituitary function. Contact endoscopy provides a noninvasive technique that allows for real-time in vivo visualization of differences in tissue vascularity. Two illustrative cases of endoscopic endonasal approaches (EEAs) for resection of pituitary adenoma illustrate the use of contact endoscopy in identifying tumor from gland and differentiating a thin section of normal gland draped over the underlying tumor, thereby allowing for safe extracapsular tumor resection. Contact endoscopy may be used as an adjunct for intraoperative, in vivo differentiation of pituitary gland and adenoma. The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21199

FOXO transcription factors are required for normal somatotrope function and growth

Understanding the molecular mechanisms underlying pituitary organogenesis and function is essential for improving therapeutics and molecular diagnoses for hypopituitarism. We previously found that deletion of the forkhead factor, Foxo1, in the pituitary gland early in development delays somatotrope differentiation. While these mice grow normally, they have reduced growth hormone expression and free serum IGF1 levels, suggesting a defect in somatotrope function. FOXO factors show functional redundancy in other tissues, so we deleted both Foxo1 and its closely related family member, Foxo3, from the primordial pituitary. We find that this results in a significant reduction in growth. Consistent with this, male and female mice in which both genes have been deleted in the pituitary gland (dKO) exhibit reduced pituitary growth hormone expression and serum IGF1 levels. Expression of the somatotrope differentiation factor, Neurod4, is reduced in these mice. This suggests a mechanism underlying proper somatotrope function is the regulation of Neurod4 expression by FOXO factors. Additionally, dKO mice have reduced Lhb expression and females also have reduced Fshb and Prl expression. These studies reveal FOXO transcription factors as important regulators of pituitary gland function.

Effects of physical activity on prolactin and thyroid hormones

Thyroid hormones thyroxine and triiodothyronine, as well as the hormone of anterior pituitary gland prolactin, play an important role in various physiological processes in the human body. In high-stress situations, these hormones act to maintain homeostasis. One of the severe stressors is physical activity. Prolactin and thyroid hormones control the energy metabolism during physical activity, and are also an important link in adaptive reactions in response to physical activity.

Morphofunctional State of the Mature Rats Pituitary Gland under Readaptation Conditions to the Long Influence of Heavy Metal Salts Complex and Correction with L-Tocopherol

The purpose of the study was to study the morphofunctional rearrangements of the structural components of the adenohypophysis of sexually mature male rats under the condition of a 30-day period of readaptation to the long-term influence of salts of heavy metals (zinc, copper, iron, manganese, lead and chromium) and taking a corrector drug. Materials and methods. The experiment was carried out on 24 white sexually mature male rats, which were divided into 1 control and 1 experimental group. The experimental group consisted of rats that consumed ordinary drinking water for 30 days after 90 days of receiving water saturated with a combination of heavy metal salts: zinc (ZnSO4 7H2O) – 5 mg / l, copper (CuSO4 5H2O) mg / l, iron (FeSO4) – 10 mg / l, manganese (MnSO4 5H2O) – 0.1 mg / l, lead (Pb (NO3) 2) – 0.1 mg / l and chromium (K2Cr2O7) – 0.1 mg / l and L-tocopherol corrector. Results and discussion. With a 30-day period of readaptation to the action of a complex of salts of heavy metals, combined with the intake of a corrector drug L-tocopherol, morphological rearrangements of a nonspecific polymorphic nature developed in the structural components of the pituitary gland: compensatory hypertrophy and increased vascularization of the pituitary gland were observed, the state of rheological properties of the blood improved, the number of chromophiles increased and the number of chromophobes decreased, the processes of cyst formation disappeared, the stress from the adaptive processes in the glandulocytes of the adenohypophysis decreased, namely their secretory activity, the expression of Hsp90α receptors in the cytoplasm of adenocytes significantly increased. Negative rearrangements include an increased value of the fibrous component of the connective tissue of the intertrabecular spaces, increased collagenization of the wall of veins and capillaries, preservation of stromal edema, plethora of hemocapillaries, the presence of a small number of adenocytes with signs of vacuolization of the cytoplasm, balloon dystrophy. Conclusion. A comprehensive study of the structural components of the adenohypophysis of the test animals under the condition of a 30-day period of readaptation to long periods of consumption of heavy metal salts and correction with L-tocopherol certainly indicate a number of adaptive and regenerative morphofunctional changes aimed at reducing the stress of adaptive processes on the part of the adenohypophysis in response to cancel the action of the stress factor

Ontogeny of Adenohypophyseal Cells, Pituitary Gland Development and Structure in Adults of Astyanax Lacustris (Teleostei, Characidae): an Emerging Neotropical Fish Species

Pituitary gland morphogenesis of the adenohypophyseal (AH) cells of Astyanax lacustris are presented herein. This Characiformes species show great ecological and commercial importance, and it has been increasingly used as a biological model. The first AH cells of A. lacustris were detected at 1 dah by the immunostaining of PRL producing cells. The morphology of the gland presented changes in shape throughout the development, starting elongated but more oval at the end. The neurohypophysis was differentiated at 3 dah, along with the identification of ACTH, MSH, TSH, and FSH producing cells. Identification of the immunoreactive cells to anti-LH, anti-SL, and anti-GH antibodies occurred at 5 dah. At 20 dah, an increase in pituitary size and the presence of the pituitary stalk were observed. At 60 dah, the pituitary already had the same shape seen in adults. The ontogeny of adenohypophyseal cells in A. lacustris corroborates the heterogeneity in the appearance of these cell types in teleosts and suggests that these hormones actively participate during the early development of this species. Our results collaborate with the understanding of the morphogenesis of the hypothalamic-pituitary-gonadal axis in South American teleosts, showing essential data for the development of future studies related to pituitary morphophysiology.