The effects of intracerebroventricularly applied ghrelin on thymocytes and thymic architecture in rats of different ages

• Main Authors: Todorović Jovana S., Terzić-Šupić Zorica J., Mazić Sanja D., Suzić-Lazić Jelena M., Žikić Dejan D., Nešić Dejan M.
• Format: Article
• Language: English
• Published: University of Belgrade, University of Novi Sad 2020-01-01
• Series: Archives of Biological Sciences
• Subjects: ghrelin; thymus; intracerebroventricularly (icv); lymphoid tissue; thymocytes
• Online Access: http://www.doiserbia.nb.rs/img/doi/0354-4664/2020/0354-46642000020T.pdf

Ghrelin positively influences the total number of thymocytes and size of the thymus in 14-, 20- and 24-month-old rats. We examined the effect of centrally-applied ghrelin on thymus weight and structure in Wistar rats of different ages. The study included 30 male Wistar rats of three age groups: peripubertal (5-week-old rats), young (2 months) and adult (6 months). The animals of each age group were divided into control and experimental groups that were administered intracerebroventricularly (ICV) 1 μg ghrelin/5 μL saline daily for five consecutive days. Following treatment, the thymuses were isolated, weighed and processed for stereological analysis by the point-counting method. The average weights of the thymuses were significantly higher in the ghrelin groups with respect to control rats (5 weeks: 444.90±18.03 vs 365.00±18.63; 2 months: 354.30±13.77 vs 257.00±9.60; 6 months: 365.00±15.90 vs 225.00±7.03, p<0.01). The absolute volume of lymphoid tissue was significantly higher in the ghrelin groups (5 weeks: 392.85±16.94 vs 294.48±33.37; 2 months: 309.30±12.10 vs 216.62±10.72; 6 months: 222.70±11.41 vs. 114.33±16.48, p<0.01). Ghrelin treatment restored thymic structure by increasing medullary cellularity, improving thymic medullary architecture and providing a clearer delineation between the cortex and medulla. This study shows the positive effects of centrally applied ghrelin on suppression of thymus atrophy, its weight and architecture. [Projects of the Serbian Ministry of Education, Science and Technological Development, Grant No. III 41025, Contract No. 175042 (2011-2014), and Grant No. 175046]