Effect of active immunization using gonadotropin-releasing hormone 2-multiple antigen peptide with different adjuvants on the reproductive functions of male rats.

This study was aimed to compare the effects of different adjuvants on male reproductive function in rats immunized using GnRH2-MAP. Male Sprague-Dawley rats were assigned to control, ISA 201 adjuvant and Gel 01 adjuvant groups along with GnRH2-MAP. The serum testosterone and antibody titers were measured every 2-week by ELISA, the testes were weighed and histologically analyzed. mRNA expression levels in the hypothalamus, pituitary, and testes were determined by RT-qPCR. Among the three groups, the ISA 201 adjuvant group exhibited the lowest testosterone concentration (P<0.05), the highest antibody titer (P<0.05), and testis atrophy. GnRH mRNA expression in the hypothalamus; GnRH-R, FSH-beta, and LH-beta expression in the pituitary; and FSH-R, LH-R, and 3 beta-HSD expression in the testes were significantly lower in this group (P<0.01). Additionally, several other genes showed significant differential expression in the ISA 201 adjuvant group than in the other two groups. It is concluded that the GnRH2-MAP vaccine emulsified with ISA 201 adjuvant is more effective than that administered with Gel 01 adjuvant. (C) 2019 PVJ. All rights reserved