Volume 56 (2006) Issue: 2006 No#5-6

Neonataly applied SRIH-14 has immediate and prolonged inhibitory effect on pituitaty GH cells

Author(s): Nestorović Nataša, Terzić Milica, Negić Nataša, Starčević Vesna, Milošević Verica

Keywords:female rats, somatostatin, somatotrophic cells, development

The immediate and prolonged effects of neonatal SRIH-14 treatment on pituitary somatotrophs (GH) were investigated. Female rats were injected s.c. twice a day with 20
g of SRIH-14/100g b.w., for five consecutive days (from 3rd to 7th day of life). Animals were sacrificed at different life periods: at neonatal (8th day), juvenile (16th day), peripubertal (38th day) and adult (80th day) period of life. GH cells were studied using the peroxidase-antiperoxidase immunocytochemical procedure. Morphometry and stereology were used to evaluate changes in the number of GH-immunoreactive cells per unit area, their volume and volume density. After SRIH-14 treatment, the most prominent decrease of all measured parameters was observed in the neonatal period. SRIH-14 induced a significant decrease of GH cell volumes and volume densities in the juvenile, peripubertal and adult periods of life. The number of GH-positive cells was significantly decreased when examined immediately after treatment, but significantly increased in adult females. Body weight, absolute or relative pituitary weights were not affected in any of the examined age groups. These findings suggest that neonatal SRIH-14 treatment exerts a significant immediate and prolonged inhibitory effect on GH cells, but does not affect the growth rate in female rats.