Immunization against recombinant GnRH-I alters ultrastructure of gonadotropin cell in an experimental boar model

Fang, Fugui; Su, Shiping; Liu, Ya; Zhang, Yunhai; Pu, Yong; Zhao, Xijie; Li, Yunsheng; Wang, Juhua; Zhou, Jie; Zhang, Xiaorong

doi:10.1186/1477-7827-11-63

Cited by 2 publications

(2 citation statements)

References 11 publications

(14 reference statements)

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“…These changes were caused by influence of the vaccination on the reduced activity of gonadotropin cells in the adenohypophysis and consequently reduced production of FSH by these cells, which is required to the process of spermatogenesis [26]. This is in correlation with the previously described ultrastructure of gonadotropin cells in GnRH immunized boars, which exhibited a decreased number and size of large and small cellular granules, indicating altered cell morphology [10].…”

Section: Discussionsupporting

confidence: 70%

“…The greater thickness as well as higher percentage of germinal epithelium in the seminiferous tubules of boars, as compared to the immunocastrates that was reported in this study, was caused by the lower FSH levels [10,11] and reduced spermatogenesis in the germinal epithelium of the seminiferous tubules of the immunocastrated males. In the testes of vaccinated animals, incomplete development or a complete lack of certain cells in the seminiferous epithelium as described earlier, was directly related to its reduced thickness.…”

Section: Discussionsupporting

confidence: 53%

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Histological and Morphometric Examination of the Testes of Boars and Male Pigs Immunocastrated with Improvac®

Stojanović

Ušćebrka

Žikić

et al. 2017

Acta Scientiae. Vet.

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Background: Surgical castration of male piglets is frequently performed to prevent development of an unpleasant taste and flavor in meat of mature males, called boar taint. Disadvantages of this method are primarily related to the lower feed efficiency of surgically castrated male pigs, production of less lean meat and more fat on the carcasses than boars, as well as ethical issues associated with the procedure itself. Immunocastration is a method of immunization against gonadotropinreleasing hormone (GnRH) and represents an alternative to avoid boar taint. This study aimed to examine the influence of immunocastration on histological and morphometric parameters of male pig testes.Materials, Methods & Results: A total of 60 crossbred male pigs selected from 30 litters were assigned to two experimental groups: boars (n = 30) and immunocastrated males (n = 30). Two doses (2 mL per dose) of the Improvac® vaccine were given to pigs scheduled for immunocastration. The first injection was given at 10 weeks of age, and the second injection at 20 weeks of age. All pigs were fed the same commercial diet ad libitum, group-housed (15 pigs/pen) and slaughtered at 25 weeks of age. After slaughter, testicle weights were measured and samples of testicular tissue were taken for histological examination. Immunocastrated males had lower testicle weights than boars (P < 0.01). Furthermore, structural damage to the germinal epithelium was visible in the seminiferous tubules of vaccinated pigs. In the testicular interstitium of these animals, the number of Leydig cells were reduced; almost all of these cells exhibited different degrees of abnormality. Moreover, the diameter of the seminiferous tubules and thickness of the germinal epithelium were greater (P < 0.01), and the percentage of germinal epithelium in the seminiferous tubules as well as percentage of blood vessels in the interstitium were higher in boars as compared to immunocastrated males (P < 0.01). Seminiferous tubule lumen diameter was greater (P < 0.01), and percentage of lumen in the seminiferous tubules as well as percentage of non-blood vessel tissue in the interstitium were higher in immunocastrated males than boars (P < 0.01).Discussion: Vaccination against GnRH, as used in this study, reduced the synthesis of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which led to decreased spermatogenesis and androgen production. The smaller diameter of the seminiferous tubules as well as germinal epithelium thickness, and lower percentage of germinal epithelium in the seminiferous tubules in immunocastrated males could be explained by reduced FSH synthesis, and subsequent reduced spermatogenesis. The described testicular malformations in immunocastrated animals caused their lower weight, and greater diameter of the lumen as well as a higher lumen percentage of the seminiferous tubules. The vaccine reduced LH synthesis, so the Leydig cells of immunocastrated animals had lower activity than the same cells in boars. The percentage of blood vessels in the interstitium of boar testes was higher, which was related to the blood supply required for normal function of Leydig cells. It was concluded that differences existed in the structure of the seminiferous tubules and interstitium between boars and immunocastrated males , which were reflected in values of the examined histological and morphometric parameters. The development of these differences was related to the inhibition of GnRH synthesis and secretion.

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Section: Discussionsupporting

confidence: 70%

Section: Discussionsupporting

confidence: 53%

Histological and Morphometric Examination of the Testes of Boars and Male Pigs Immunocastrated with Improvac®

Stojanović

Ušćebrka

Žikić

et al. 2017

Acta Scientiae. Vet.

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Effect of active immunization against GnRH‐I on the reproductive function in cat

Jiang

Hong

et al. 2015

Animal Science Journal

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This study was designed to explore the effect of active immunization against maltose binding protein-gonadotropin releasing hormone I hexamer (MBP-GnRH-I6) on the reproductive function in cats. Each immunized cat was administered twice intramuscularly in the neck at 16 and 20 weeks old. The concentrations of the testosterone and estradiol and the level of anti-GnRH-I antibody in the serum were measured by radioimmunoassay and ELISA, respectively. The results showed that the weight and size of testicles and ovaries, and the concentrations of serum testosterone and estradiol in the immunized animals were lower than those of the control cats (P < 0.05), but that the levels of anti-GnRH-I antibody were significant higher compared to control animals (P < 0.05). Testicular tissues from the immunized male cats showed that seminiferous tubules were depauperate with the lumen relatively empty and that the differentiation of spermatogonia was not obvious. Tissues from the immunized female cats showed that the ovaries had many primordial follicles and primary follicles, but no secondary follicle was observed. These results showed active immunization against MBP-GnRH-I6 could make the gonads atrophy and reduce the concentrations of gonadal hormones, which suggested that MBP-GnRH-I6 was a very effective immunogen in the cat.

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Immunization against recombinant GnRH-I alters ultrastructure of gonadotropin cell in an experimental boar model

Cited by 2 publications

References 11 publications

Histological and Morphometric Examination of the Testes of Boars and Male Pigs Immunocastrated with Improvac®

Histological and Morphometric Examination of the Testes of Boars and Male Pigs Immunocastrated with Improvac®

Effect of active immunization against GnRH‐I on the reproductive function in cat

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