Morphology and ultrastructure of the hypophysis in bactrian camels ( Camelus bactrianus ) / Morfología y ultraestructura de la hipófisis en camellos bactrianos ( Camelus bactrianus )

The morphology of the hypophysis in Bactrian camel has not been described in the literature, despite it being the master of endocrine organs in vertebrates. In the present study, we examined the morphological features of the hypophysis in Bactrian camel by means of gross anatomy, light and electron microscope. Our findings showed that the gland was a protrusion of the bottom of the hypothalamus at the base of the brain with about 1.54 g in weight and 2 cm3 in volume. The hypophysis consists of two major parts: fully developed adenohypophysis and underdeveloped neurohypophysis, the adenohypophysis consists of pars distalis and pars intermedia. Seven type cells of the pars distalis could be distinguished with immunohistochemical techniques and electron micrographs: somatotroph, mammotroph, thyrotroph, corticotroph, gonadotroph, chromophobe and stellate cells which is in accordance with most mammals. Notably, the stellate cells could be obviously distinguished from chromophobe cells in histological oberservation. Moreover, the corpusculum neurosecretorium (Herring bodies) were rare in the external neurohypophysis, and mainly distributed in the internal neurohypophysis, this was different from most mammals. Results from this study would provide a necessary theoretical basis for ongoing investigations for Bactrian camels and their good adaptability in arid and semi-arid circumstances.

La morfología de la hipófisis en el camello bactriano no ha sido descrita en la literatura, a pesar de ser el maestro de los órganos endocrinos en los vertebrados. En el presente estudio, examinamos las características morfológicas de la hipófisis del camello bactriano por medio de anatomía general, microscocopía de luz y microscopía electrónica. Nuestros hallazgos mostraron que la hipófisis es una protuberancia ubicada en la porción inferior del hipotálamo, en la base del cerebro, con aproximadamente 1,54 g de peso y 2 cm3 de volumen. La hipófisis consta de dos partes principales: adenohipófisis, completamente desarrollada, y neurohipófisis, poco desarrollada; además, la adenohipófisis consta de una pars distalis y una pars intermedia. Con técnicas inmunohistoquímicas y micrografías electrónicas en la pars distalis se pudieron distinguir siete tipos de células: somatotrofas, mamotróficas, tirotrofas, corticotrofas, gonadotrofas, cromófobas y estrelladas, lo que es similar a la mayoría de los mamíferos. En la observación histológica las células estrelladas se pueden distinguir naturalmente de las células cromófobas. Además, es rara la presencia de corpusculum neurosecretorium (Cuerpos de Herring) en la neurohipófisis externa, hallándose distribuidos principalmente en la neurohipófisis interna, esto es diferente a lo encontrado en la mayoría de los mamíferos. Los resultados de este estudio proporcionarían una base teórica necesaria para las investigaciones en curso de los camellos bactrianos y su buena adaptabilidad en circunstancias áridas y semiáridas.

effect of aspartame on the pituitary thyroid axis of adult male albino rat and the possible protective effect of Pimpinella anisum oil: histological and immunohistochemical study

Aspartame is a synthetic sweetener. Its metabolites can be toxic to many organs such as liver and kidney. Pimpinella anisum [P. anisum] has been used for different purposes as an antioxidant, hepatoprotective, and anti-inflammatory agent. The present work was carried out to study the histological changes in the pituitary thyroid axis of adult male albino rats after aspartame treatment and the possible role of P. anisum in minimizing these changes. Twenty-five adult male Albino rats were used. They were divided into three groups: group I was the control group, group II received 250 mg/kg/day aspartame once daily for 2 months, and group III received prophylactic P. anisum oil 0.5 ml/kg/day once daily, followed by aspartame after 2 h for 2 months. At the end of the experiment, the rats were sacrificed. The thyroid and pituitary gland tissue samples were processed for light microscopic and electron examination. Also, an immunohistochemical study was carried out for the detection of thyrotrophs. Light microscopic examination of aspartame-treated animal showed loss of architecture of the thyroid gland. Many follicles were small in size and others had disrupted wall and detached cells in their lumens. Some thyrocyte had pyknotic nuclei and deeply stained vacuolated cytoplasm. There was a highly significant increase in the number of positive immunostained thyroid-stimulating hormone cells. Most cells in pars distalis were hypertrophied with eccentric nuclei and a large negative Golgi image. The thyrotrophs and somatotrophs had dilated cisternae of rough endoplasmic reticulum, destroyed mitochondria, and few secretory granules. Some cells with secretory granules of both somatotrophs and thyrotrophs were frequently observed. The administration of P. anisum induced improvements in the degenerative changes of this axis. From this study, it could be concluded that prolonged consumption of aspartame induced disturbance in the pituitary thyroid axis. The use of P. anisum decreased the toxic effect of aspartame

Histological, immunohistochemical and electron microscopic studies on the effect of melatonin on pituitary-testicular axis in aged male albino rat

Aging is a biological process affecting mammalian tissues and organs at different rates. The present work was done to study the effect of melatonin as anti-aging therapy on the structure of the testis and the pars distalis. A total number of 25 male albino rats were used. The animals were divided into three groups: group [I] served as a control adult group [6 months age], group [II] was the control aged group [20-months age] and group [III] was treated with melatonin. The specimens of the testis and pituitary glands were prepared for light and electron microscopy. Histological and immunohistochemical techniques were used to examine these organs. It was found that age-related changes occur in the histological immunohistochemistry and ultrastructure of the testis and pituitary gland. Also, treatment with melatonin as anti-oxidant and free radical scavenger caused improvement of these changes in the pituitary gland as well as the testis. The age-related changes that occurred in the testis included progressive involution and germ cells depletion in the seminiferous tubules which contained only Sertoli cells. Ultrastructural apoptotic changes of germ cells increased with aging and abnormal morphology of the resulting sperms were found. This might result in decapacitating sperm function increase in interstitial tissue. Leydig cells exhibited ultrastructural changes which might lead to a decrease in their activity and testosterone production. As regard the pituitary gland; different utrastructural changes occurred in the somatotrophs or GH cells. The ultrastructrual and immunohistochemical studies of gonadotrophs or LH/FSH cells showed marked deterioration with progression of age. Treatment with melatonin from the adult state improved the morphological and ultrastructural changes that occurred with aging

Histological structure of male rat pituitary gland following treatment with paracetamol singly or concomitantly with honey

Paracetamol, also known as acetaminophen, is one of the most commonly used drugs as an analgesic and anti-inflammatory. Paracetamol contains a phenol ring and an acetyl group raising the possibility that it might have sex steroid antagonist properties. A small proportion of the drug is metabolized into a reactive metabolite, which is normally detoxified by glutathione. Over dose might cause glutathione depletion and oxidative stress. Honey is considered as an antioxidant because of the presence of ascorbic acid, flavonoid and alpha-tocopherol. This work was carried out to investigate the morphological modifications that would occur in the pituitary gland of male rats in response to the administration of acetaminophen in therapeutic dose for one month duration and a possible protective effect of honey when given concomitantly with paracetamol. Thirty adult male albino rats were used. The animals were divided into three groups. Group I served as a control Group II were given paracetamol orally in a dose of 800 mg/kg/day for one month. Group III were given paracetamol in a similar dose and duration concomitantly with honey in a dose of 2.5 gm/kg/day orally. All the animals were sacrificed and the pituitary gland was dissected out and processed for general histological and ultrastructural examination of the pars distalis. The pars distalis of group II revealed variable structural changes in the gonadotrophs and somatotrophs. In group III the changes extended to involve the thyrotrophs. The most characteristic change was the excessive dilatation in ER. It is concluded that paracetamol influences the structure of pars distalis in a selective form. Honey modifies paracetamol effect, possibly via its ascorbic acid contents

Electron microscopical studies of pituitary gland of male hamsters under the effect of estrogen treatment

The ultrastructure of the normal pars intermedia of male hamsters showed two types of cells. The light cells were numerous, regular in shape with rounded or elongated nuclei have different size of secretory granules and were considered as a source of melanocyte stimulating hormone [MSH]. The dark cells were less in number, showed less display of secretory granules and were concerned with colloid production. Some of the dark cells showed foot like processes and irregular nuclear membranes. Progressive changes in the cell organelles were observed in the pars intermedia cells after long term of estrogen treated hamsters over the studied period

Morphometric and ultrastructural analysis of different pituitary cell populations in undernourished monkeys

Undernutrition elicited by a low-protein diet determines a marked reduction of hypophyseal activity and affects the function of the respective target organs. The objective of the present investigation was to study the ultrastructural and quantitative immunohistochemical changes of the different pituitary cell populations in undernourished monkeys that had been previously shown to have significant changes in craniofacial growth. Twenty Saimiri sciureus boliviensis monkeys of both sexes were used. The animals were born in captivity and were separated into two groups at one year of age, i.e., control and undernourished animals. The monkeys were fed ad libitum a 20 percent (control group) and a 10 percent (experimental group) protein diet for two years. Pituitaries were processed for light and electron microscopy. The former was immunolabeled with anti-GH, -PRL, -LH, -FSH, -ACTH, and -TSH sera. Volume density and cell density were measured using an image analyzer. Quantitative immunohistochemistry revealed a decrease in these parameters with regard to somatotrophs, lactotrophs, gonadotrophs and thyrotrophs from undernourished animals compared to control ones. In these populations, the ultrastructural study showed changes suggesting compensatory hyperfunction. On the contrary, no significant changes were found in the morphometric parameters or the ultrastructure of the corticotroph population. We conclude that in undernourished monkeys the somatotroph, lactotroph, gonadotroph, and thyrotroph cell populations showed quantitative immunohistochemical changes that can be correlated with ultrastructural findings

Atypical flagellar structure associated with endocrine cells of rat pituitary.

Atypical flagellar structures containing eight subfibers arrayed around a single, central element (8 + 1) are associated with pituitary secretory cells, largely gonadotropes. Less frequently, flagella with a 7 + 2 pattern are seen. Both types appear commonly in pituitary tissues obtained from both male and female rats above 1 year of age and appear to penetrate the cells. Except for the pattern of the array, the structures are similar in dimension to commonly observed flagellar structures (9 + 2) when viewed in sections cut either in perpendicular or sagittal to the major axis. The (8 + 1) flagella are observed both singly and in pairs. Steroidal milieu (ovariectomy with or without steroid replacement) does not seem to influence their appearance. Flagella with the common 9 + 2 arrangement are not observed in the rat pituitary.