Histochemical and fine structure studies of pituitary cell type distribution with special emphasis of gonadotrophs during annual reproductive cycle of the adult female white seabream (Diplodus sargus) | ||||
| Egyptian Journal of Aquatic Biology and Fisheries | ||||
| Article 12, Volume 22, 5 (Special Issue), November 2018, Page 175-187 PDF (467.37 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/ejabf.2018.19516 | ||||
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| Authors | ||||
| Rania F. Ismail; Reham M. K. Negm | ||||
| Laboratory of Fish Reproduction and Spawning, Aquaculture Division, National Institute of Oceanography & Fisheries, Kayet-bey, Alexandria, Egypt | ||||
| Abstract | ||||
| The ovarian cycle of the female white seabream (Diplodus sargus) can be explained as five stages as follows: Immature, Maturing, Nearly ripe , Ripe and Running and Spent stage, whereas the peak of gonadostmatic index was reported between January to April, with an average GSI value of 2.64 ± 0.6. The adenohypophysis of white seabream was investigated using histochemical and electron microscopy techniques. It can be subdivided into three distinct regions: rostral pars distails (RPD), proximal pars distails (PPD) and pars intermedia (PI). Six cell types were identified and localized in the adenohypophysis. The acidophilic prolactin (PRL) and adrenocorticotropic hormone secreting cell (ACTH) were found in the RPD region. The ACTH cells were generally arranged between neurohypophysis and PRL cells. The melanocyte stimulating hormone secreting cells (MSH) and somatotrops cells (STH) were acidophilic and detected in the PPD and RPD regions. The basophilic cells were gonadotrophic cells (GTH) and the thyrotrophic cells (TSH); one type of the GTH cells was detected in D. sargus pituitary. The GTH cells displayed variations through the reproductive cycle, while all four types of acidophilic cell and TSH cells did not show any variations in size and activity throughout the reproductive cycle. During immature and mature stages GTH cells showed the minimum granulation and smaller cell size, at nearly-ripe stage the GTH cells were characterized by intense accumulation of granules and reached to maximum diameters (p<0.05) as demonstrated by electron microscope. During ripening and running stage (from January to April), slight decrease in the GTH cell diameters and its staining affinity and granulation were observed. During the spent stage (from April to June) the GTH cells displayed faint stain with presence of vacuoles between cells with minimum amount of granulation. | ||||
| Keywords | ||||
| Pituitary gland; histochemistry; Electron Microscope; reproductive cycle; Diplodus sargus | ||||
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