Effect of high altitude hypoxia on the postnatal development of rat testis: histological and histometric study / Efecto de la hipoxia a gran altitud en el desarrollo postnatal en testículos de rata: estudio histológico e histométrico

The study was carried out at two different altitudes in the southern region of Saudi Arabia: Abha, 2,800 meters above sea level, the high altitude (HA) area and Jazan, 40 meters above sea level the low altitude (LA) area. Following exposure to high altitude, and up to the third week of postnatal development, some of the seminiferous tubules showed detachment from the basal lamina, spaces of different sizes within the epithelial layer with vacuoles in the center and Pyknotic nuclei were noted in the spermatogonia and primordial germ cells. Rounded spermatids were seen in the lumen only on day 35 of hypoxic group, no spermatozoa were recognized until day 45 of postnatal development. On day 45 hypoxic rat testes revealed various types of atrophy and degeneration in the seminiferous tubules and in the interstitial tissue, there was detachment of the basal laminae of the tubules and a profound decrease in cellularity. Significant decrease in epithelial height was noticed in these animals (P <0.05). Also, the diameter of the tubules showed slight decrease with concomitant increase in interstitial spaces in all hypoxic rats.

El estudio se llevó a cabo en dos sitios de altitud diferentes en la región sur de Arabia Saudita: en Abha, a 2.800 metros sobre el nivel del mar, la zona de gran altitud (GA) y en Jazan, a 40 metros sobre el nivel del mar, la zona de baja altitud. Después de la exposición a GA, y hasta la tercera semana del desarrollo postnatal, se observaron espermatogonias y células germinales primordiales en algunos túbulos seminíferos, un desprendimiento de la lámina basal, espacios de diferentes tamaños dentro de la capa epitelial, con vacuolas en el centro y núcleos picnóticos. Se encontraron espermátidas redondeadas a nivel del lumen en el día 35 de la hipoxia, y no se observaron espermatozoides hasta el día 45 del desarrollo postnatal. En el día 45, los testículos de las ratas hipóxicas revelaron varios tipos de atrofia y degeneración en los túbulos seminíferos y el tejido intersticial; no hubo separación de las láminas basales de los túbulos y se registró una profunda disminución de la celularidad. Además, se observó una disminución significativa en la altura del epitelio de estos animales (P <0,05). El diámetro de los túbulos mostró una ligera disminución con el aumento concomitante en los espacios intersticiales en todas las ratas hipóxicas.

Reversible effect of high altitude on rat testis morphology and spermatogenesis: histological and ultrastructural study / Efecto reversible de la altitud elevada sobre la morfología y espermatogénesis en el testículo de rata: estudios histológico y ultraestructural

The study was carried out at two different altitudes in the southern region of Saudi Arabia: Abha, 2,800 meters above sea level, the high altitude (HA) area and Jazan, 40 meters above sea level the low altitude (LA) area. Following exposure to high altitude, testes of rats revealed various types of atrophy and degeneration in the seminiferous tubules and in the interstitial tissue. There was detachment of the basal laminae of the tubules and a profound decrease in cellularity. When rats were brought back to their habitat (LA) and later examined, many tubules showed normal population of cells including spermatids and spermatozoa. Well-arranged epithelium was seen in most of the seminiferous tubules of these animals, normal interstitial space and no detachment of the basal lamina. Apparently complete recovery had been achieved ultrastructurally, in hypoxic group; some spermatogenic cells lost their normal architecture, being irregular in shape with some features of necrosis, such as shrinkage and pyknotic nuclei characterized by chromatin condensation. Significant decrease in epithelial height was noticed in these animals (P <0.05). Also, the diameter of the tubules showed slight decrease with concomitant increase in interstitial spaces.

El estudio se realizó en dos ciudades con alturas diferentes en la región sur de Arabia Saudita: Abha, a 2.800 metros sobre el nivel del mar, una zona de gran altura (GA) y Jazan, a 40 metros sobre el nivel del mar, área de baja altitud (BA). Después de la exposición a una gran altura, los testículos de ratas revelaron varios tipos de atrofia y degeneración en los túbulos seminíferos y en el tejido intersticial. Hubo desprendimiento de la lámina basal de los túbulos y una disminución profunda en la celularidad. Cuando las ratas fueron devueltas a su hábitat (BA) y posteriormente examinadas, muchos túbulos mostraron un número normal de células, incluyendo espermáticas y espermatozoides. El epitelio se observó normal en la mayoría de los túbulos seminíferos de estos animales, con el espacio intersticial normal y sin desprendimiento de la lámina basal. Al parecer, se logró una recuperación ultraestructural completa en el grupo de hipoxia; algunas células de espermatogénesis perdieron su arquitectura normal, siendo de forma irregular con algunas características de necrosis, como la contracción y núcleos picnóticos caracterizados por condensación de la cromatina. Se observó disminución significativa en la altura del epitelio en estos animales (P <0,05). Además, el diámetro de los túbulos mostró una ligera disminución con aumento concomitante en los espacios intersticiales.

Studies on the poll glands of the one-humped camel in relation to reproductive activity. II. Ultrastructural observations.

An alveolus of an active poll gland is lined with cells in various stages of secretory activity. The cells are generally tall and characterised by the presence of a spherical nucleus, a massive Golgi complex, numerous mitochondria, granular endoplasmic reticulum, many ribosomes and secretory granules; these are features which constitute evidence of high metabolic and secretory activities. An alveolus of a resting gland, on the other hand, is lined with low inactive cells possessing an infolded nucleus, an inconspicuous Golgi complex and a few other organelles; secretory granules are virtually absent. The alveolar cells undergo a cyclic merocrine secretory activity yielding a proteinaceous product. It is suggested also that the gland may be a steroid-dependent organ accumulating or possibly synthesising steroids and releasing them through a mechanism as yet unknown.

Morphology of the testis of the one-humped camel in relation to reproductive activity.

Histological and morphometric studies on the camel testis have been carried out systematically at regular monthly intervals during a period of one year. The testicular weight was minimal during summer, while the maximum weight was attained during the coldest months from November until March. Diameters of the seminiferous tubules were multiphasic with a tendency to be wider during summer. The ratio of the area occupied by seminiferous tubules to that occupied by interstitial tissue revealed that the latter occupied a larger area than that of the seminiferous tubules during winter, while a reversed relationship occurred from March onwards and was especially marked after April, i.e. in summer. In addition, spermatogenesis was noted in all testes examined throughout the year; however, there was a difference in the quality and quantity of spermatogenic cells between the monthly groups evaluated. November, December and January were the months in which spermatogenic activity was most striking. A correlation was established between testicular weight, amount and quality of testicular interstitial tissue, spermatogenesis and epididymal sperm content and, hence, testicular function on the one hand and season of the year on the other hand. The cyclic structural changes in the testis appeared to be in parallel with the rutting activity of the camel. It was suggested also that the camel is not a typical seasonal breeder as it does not go through sexual quiescence. The reproductive activity of the camel builds up during September and October, and the animal is in actual rut during November, December, January and February, with a drop in March and thereafter.

Studies on the poll glands of the one-humped camel in relation to reproductive activity. I. Seasonal morphological and histochemical changes.

The poll glands of the camel have been studied histologically and histochemically. An active gland, as observed between September and March, with a peak period in November and December, consists of sharply demarcated lobules separated by thin strands of connective tissue. Alveoli and proximal parts of excretory ducts are either lined with flat/simple cuboidal epithelium or with tall cells possessing distal protruding tips almost occluding the lumina; both segments, i.e. alveolus and proximal part of excretory duct, are therefore secretory. In the inactive gland there is an apparent increase in the interlobular stroma with massive deposition of collagenous fibres. The alveoli are lined with squamous to low columnar epithelium. The structural appearance in the castrate animal is essentially the same as that of the inactive gland except for its remarkable amount of interlobular tissue. Both delta 5-3 beta- and 17 beta-hydroxysteroid dehydrogenases have been demonstrated histochemically in the secretory portions of the gland. Their activity is restricted to the period between September and March and is comparatively highest during November and December. It is concluded that the morphological, enzymatic and secretory activities of the poll gland are correlated with testicular activity and rutting behaviour. It is suggested that the poll glands could be a source of sex pheromones.

The fine structure of the boundary tissue of the seminiferous tubule of the camel (Camelus dromedarius).

An ultrastructural study of the boundary tissue of the seminiferous tubule of the camel reveals that it consists of three lamellae; inner fibrous, inner cellular and outer cellular. The inner lamella is subdivided into two homogeneous layers enclosing a third one that contains collagenous fibres and fine filaments. The inner cellular lamella consists of several layers of myoid cells; each layer is separated from the adjacent layer by homogeneous material and varying amounts of collagen. The outer cellular lamella consists predominantly of fibrocytes together with some fibroblasts and scattered collagen.

On the regional histology and histochemistry of the epididymis of the camel (Camelus dromedarius).

Distinct morphological regions, initial, middle and terminal segments, were distinguishable histologically; the middle segment was further subdivided into proximal, intermediated and distal parts. PAS-positive, diastase-resistant reaction was detected in the blood vessels, subepithelial tissue and stereocilia of all segments. Acid phosphatase was demonstrated in the epithelial cells with the highest activity being in the proximal part of the middle segment. Non-specific esterase gave a similar reaction but the strongest activity was in the terminal segment. Alkaline phosphatase, adenosine triphosphatase and adenosine monophosphatase were of similar activity in the subepithelial tissue, blood vessels, stereocilia and luminal contents; the strongest reaction occurred in the middle segment. Lactate, succinate, glutamate and glucose-6-phosphate dehydrogenases were examined; LDH was more active than the others particularly in the terminal segment. Some reaction was found in the epithelial cells, subepithelial tissue and luminal contents.

Vascular supply of the testis of the camel (Camelus dromedarius).

The origin, pattern of distribution and the length of the convoluted part of the testicular artery were examined by blunt dissection and by the preparation of arterial casts with vinylite. The testicular artery originates from the abdominal aorta just cranial to its bifurcation and forms compact coils and reveals a tortuous course in the region of the pampiniform plexus and along the attached border. The artery divides at the caudal extremity of the testis into 2--4 branches. The epididymal artery, which is a branch of the testicular artery, was seen to anastomose with the deferential artery, but no anastomosis occurs between these arteries and the testicular artery. The convoluted part of the testicular artery was 20 cm in length, but when unravelled totalled 240 cm. This is not affected by seasonal variations. The possible significance of these results was discussed and compared with similar findings of other mammals.

Histological observations on the testis of the camel, with special emphasis on spermatogenesis.

A histological study of the testis of the camel has been carried out; this includes the description of the different cell types of the testis, stages and frequency of the cycle of the seminiferous epithelium. The testis is characterized by the presence of abundant Leydig cells found in large masses in the intertubular areas and in the mediastinum. The cycle of the seminiferous epithelium was divided into eight stages (I-VIII) according to the method of Ortavant. The frequency of the stages I-VIII of the cycle is not affected by season and was found as follows: I:21.93%; II: 11.07%; III: 13.42%; IV: 8,24%; V: 10.32%; VI: 9.34%; VII: 9,25%; VIII: 16.43%.

Some histochemical studies on the prostate, urethral and bulbourethral glands of the one-humped camel (Camelus dromedarius).

The histochemical localization of carbohydrates, ribonucleoproteins (RNA), lipids, some hydrolytic enzymes, succinate and lactate dehydrogenase and acetylcholinesterase were investigated in the prostate, urethral and bulbourethral glands of the camel. These glands probably secrete carbohydrate-protein complexes. In the bulbourethral glands, they are sulphated mucopolysaccharides. RNA was seen in the cytoplasm of the prostate and urethral glands. Neutral lipids were cytoplasmic and present in moderate amounts in the prostate and urethral glands and in traces, in the bulbourethral gland. Acid phosphatase-containing granules were abundant in the prostate, moderate in the urethral glands and in traces in the bulbourethral glands. Alkaline phosphatase was observed in the apical cytoplasm of the prostate and bulbourethral glands and in the ducts of the urethral glands. ATPase and adenosine 5-monophosphatase were seen in the basal laminae and interstitial tissue. In the urethral glands, adenosine 5-monophosphatase was distributed diffusely in the cytoplasm. Succinate dehydrogenase was seen in the urethral and bulbourethral glands. Varying degrees of lactate dehydrogenase activity was observed in all the glands. Acetylcholinesterase was confined to neural elements. The pars disseminata and the urethral glands were considered as two distinct glandular zones along the pelvic urethra. The significance of these histochemical results is discussed.

Studies on the testis of the camel (Camelus dromedarius). III. Histochemical observations.

The histochemical localization of carbohydrates and lipids and some oxidative, hydrolytic and steroid-linked enzymes has been studied in the testis of the camel with particular reference to the effect of the season on the distribution of these substances. PAS-positive, but diastase-resistant, material was seen mainly in the wall of blood vessels and in the boundary tissues of the seminiferous tubules, tubuli recti and rete testis. Clear cyclical changes were seen for glycogen in the lining epithelium of the seminiferous tubules. Glycogen was most abundant in early stages and very scanty or absent in the late stages of the cycle of the seminiferous epithelium. Numerous small lipid droplets were seen in the interstitial cells and towards the lumen of the seminiferous tubules that contain elongate spermatids or spermatozoa. Large lipid droplets were also demonstrable in the basal layer of the seminiferous epithelium and in the cytoplasmic debri. Alkaline phosphatase was demonstrated in the boundary tissues of the seminiferous tubules, tubuli recti and reti testis and in the cells bordering the lumen of the seminiferous tubules. Succinate and lactic dehydrogenases showed similar patterns of distribution in the interstitial elements and intratubularly. delta5-3beta hydroxysteroid dehydrogenase was exclusively demonstrated in the interstitial cells. 17beta-hydroxysteroid dehydrogenase could not be demonstrated. The season seems to have no effect on the distribution of all these substances. The possible significance of all these findings is discussed.