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This study was designed to monitor the morphological development of the reproductive tract of the Nubian bucks in relation to puberty. Thirty-two Nubain male kids were used in the study. The animals were slaughtered at intervals of 2 weeks starting from 1 day old up to 24 weeks of age. Tissue samples were obtained from the testes and processed for ultrastructural studies. The boundary tissue of the newly forming seminiferous tubule adhered closely to the basal lamina. It consisted of a single continuous layer of myoid cells, the outer surface of which was covered by scattered fibroblasts. The ultrastructural study of the boundary of the seminiferous tubule revealed that it consisted of three layers; inner fibrous, middle and outer cellular. The seminiferous tubules at week one were lined by two layers of epithelia; spermatogonia and Sertoli cells in the basal layer, and primary spermatocytes in the second layer. A gradual increase in the diameter of the tubules and epithelial height continued to increase with age. Furthermore, spermatocytes number showed an increase with age. In conclusion, based on the appearance of spermatozoa in the lumina of the seminiferous tubules, puberty age was achieved between weeks 18 and 20., (© 2022 Wiley-VCH GmbH.)

The aim of the study was to provide values for morphometric parameters of histological components of normally delivered full term placentas of Sudanese women and compare them with reported parameters for other ethnic groups. A total of 200 histological sections, stained with hematoxylin and eosin and trichrome stains were used to give a final sample of 1000 fields saved as PowerPoint images for histomorphometry. A systematic random sampling procedure was adopted to ensure the optimum sample size that keeps the percentage error below 5% for the volume estimates. Standard stereological methods of point-counting and intersection-counting were applied to the microscopic fields to determine the volumes of placental components and surface area of fetal-maternal interface. The morphometric parameters showed no variations either between the placentas or between central and peripheral regions. The placental villi and the intervillus space occupied 65% and 35% of placental volume respectively with mean absolute values of 318 cm(3) and 169 cm(3). The mean absolute volume of the intervillus space was less than that of other ethnic groups by 8.67% but was significantly larger than that of the fetal capillaries which measured 41.2 cm(3). The ratio of the absolute volume of the intervillus space to the volume of the fetal blood capillaries was 4:1 in both Sudanese and other ethnic groups. In the placental villi the fetal connective tissue together with the contained blood vessels larger than capillaries occupied 88% of the villus volume. The mean surface area of the fetal-maternal interface of the placental villi (syncytiotrophoblast) was 12.59 M(2).

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.

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 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.

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.

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 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.

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%.

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.

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.