The Sex Differences of Morphology and Immunology of SIRS of Newborn Wistar Rats

The sex differences of infection and inflammatory diseases particularly appear at reproductive age and depend on the sex hormone level, varied between male and female. There are a few sets of data about the sex differences of infection and inflammatory diseases course, including systemic inflammatory response syndrome (SIRS) and sepsis, of newborns. The aim of our research was the estimation of morphological and immunological manifestation of SIRS of the newborn Wistar rats. Investigations were carried out on male and female two-day-old Wistar rats (10–12 g). SIRS was modeled by intraperitoneal injection of LPS (E. coli, O26: B6 strain, Sigma) in high dose—15 mg/kg. We did not find out any sex differences of the liver lesions severity between newborn males and females after LPS injection. The levels of endotoxin and estradiol in the serum, as the number of neutrophils in the intra-alveolar septa of the lungs, were higher in males than females with SIRS. Production of IL-2 and TNF-α by the spleen cells of males was higher than that in control group that reflects polarization predominantly on the Th1-type immune response. The secretion of IL-2, TNF-α, and IFN-γ by ConA activated spleen cells of females decreased that reflects the suppression of Th1-type immune response. We suppose that the LPS administration in the high dose causes the multidirectional reaction of the immune system of neonatal males and females Wistar rats.