## 4 Discussion
\begin{table}
\begin{tabular}{l c c} \hline  & **PACAP WT** & **PACAP HZ Mice** \\ \hline White blood cell count (WBC) [10\({}^{9}\)/L] & 3.56 \(\pm\) 0.42 & 3.95 \(\pm\) 0.66 \\ Red blood cell count (RBC) [10\({}^{12}\)/L] & 8.40 \(\pm\) 0.36 & 7.91 \(\pm\) 0.20 \\ Hemoglobin concentration (HGB) [g/L] & 123.91 \(\pm\) 3.36 & 121.90 \(\pm\) 2.21 \\ Haematocrit (HCT) [\%] & 37.92 \(\pm\) 1.27 & 36.31 \(\pm\) 0.80 \\ Mean corpuscular volume (MCV) [fL] & 45.50 \(\pm\) 1.16 & 45.91 \(\pm\) 0.24 \\ Mean corpuscular hemoglobin (MCH) [pg] & 14.88 \(\pm\) 0.34 & 15.45 \(\pm\) 0.15 \\ Mean corpuscular hemoglobin concentration (MCHC) [g/L] & 327.64 \(\pm\) 3.05 & 335.90 \(\pm\) 1.66 \({}^{*}\) \\ Platelet count measured with optical method (PLT\&Q) [10\({}^{9}\)/L] & 1324 \(\pm\) 260.25 & 1394.1 \(\pm\) 66.01 \\ Red cell distribution width—standard deviation (RDW-SD) [fL] & 27.15 \(\pm\) 1.86 & 23.2 \(\pm\) 0.24 \({}^{*}\) \\ Red cell distribution width—coefficient of variation (RDW-CV) [\%] & 18.89 \(\pm\) 1.24 & 15.87 \(\pm\) 0.31 \({}^{*}\) \\ Platelet distribution width (PDW) [fL] & 7.06 \(\pm\) 0.15 & 6.81 \(\pm\) 0.06 \\ Mean platelet volume (MPV) [fL] & 7.26 \(\pm\) 0.27 & 6.93 \(\pm\) 0.03 \\ Platelet large cell ratio (P-LCR) [\%] & 9.62 \(\pm\) 3.05 & 4.63 \(\pm\) 0.27 \\ Plateletocrit (PCT) [\%] & 0.75 \(\pm\) 0.09 & 10.03 \(\pm\) 0.06 \({}^{**}\) \\ Nucleated red blood cell (NRBC) [10\({}^{9}\)/L] & 0.06 \(\pm\) 0.01 & 0.03 \(\pm\) 0.01 \({}^{**}\) \\ Neutrophil granulocyte count (NEUT) [10\({}^{9}\)/L] & 0.93 \(\pm\) 0.12 & 0.78 \(\pm\) 0.08 \\ Lymphocyte count (LYMPH) [10\({}^{9}\)/L] & 2.16 \(\pm\) 0.28 & 2.63 \(\pm\) 0.51 \\ Monocyte count (MONO) [10\({}^{9}\)/L] & 0.30 \(\pm\) 0.04 & 0.33 \(\pm\) 0.06 \\ Eosinophil granulocyte count (EO) [10\({}^{9}\)/L] & 0.15 \(\pm\) 0.01 & 0.17 \(\pm\) 0.03 \\ Basophil granulocyte count (BASO) [10\({}^{9}\)/L] & 0.00 \(\pm\) 0.00 & 0.00 \(\pm\) 0.00 \\ reticulocyte count (RET) [\%] & 4.19 \(\pm\) 0.19 & 3.73 \(\pm\) 0.01 \({}^{*}\) \\ Immuture reticulocyte fraction (IRF) [\%] & 52.45 \(\pm\) 1.06 & 51.26 \(\pm\) 0.46 \\ Reticulocytes with low fluorescence (LFR) [\%] & 47.55 \(\pm\) 1.06 & 48.74 \(\pm\) 0.46 \\ Reticulocytes with median fluorescence (MFR) [\%] & 12.60 \(\pm\) 0.38 & 11.10 \(\pm\) 0.16 \({}^{**}\) \\ Reticulocytes with high fluorescence (HFR) [\%] & 39.86 \(\pm\) 0.89 & 40.16 \(\pm\) 0.53 \\ Reticulocyte hemoglobin equivalent (RET-HE) [pg] & 17.34 \(\pm\) 0.33 & 18.45 \(\pm\) 0.08 \({}^{**}\) \\ \hline \end{tabular}
\end{table} 
Table 2: Blood count in wild type (WT) and PACAP heterozygous (HZ) mice. Results are given in mean \(\pm\) S.E.M. \({}^{*}\)\(p\) \(<\) 0.05, \({}^{**}\)\(p\) \(<\) 0.01 compared to wild type mice. distinguishable signs from wild type mice at birth [30]. Our results can be added to this last group of observations, as we found no differences between WT and PAC1 receptor KO mice in organ morphology and gross appearance, even at older age. However, it has to be noted that the early postnatal mortality of the newborns was high, which made the breeding of the animals extremely complicated. The differences may depend on mouse strain, environmental conditions, and several other factors. In contrast to PAC1 receptor KO mice, we found several alterations in PACAP-deficient animals. In the present study we aimed at investigating the effects of a partial lack of the peptide. Complete PACAP deficiency in PACAP homozygous knockout mice has been shown to have severe consequences in numerous physiological and pathological processes. Among others, mice with a complete lack of PACAP have high mortality, altered axonal arborization in the dentate gyrus [63], disturbed energy balance [64], and reduced food intake [65]. PACAP deficiency leads to increased vulnerability towards different stressors. This has been reviewed in numerous studies [22; 66; 67].