Fig. 2

Endocannabinoid synthesis in human fetal testis. AEA (A) and 2-AG (B) concentrations measured by mass spectrometry in human fetal testes at 7–8 DW (n = 7), 8–10 DW (n = 9), and 10–12 DW (n = 7). Data in pmol per mg of proteins in the tissue are presented as mean + / − SEM. ANOVA test was performed followed by Kruskal–Wallis test for pair comparisons (a and b: p < 0.01). (C) MALDI images showing the distribution of two prototypic lipids in the fetal testis: [PC(32:0) + K]⁺ (m/z 772.5254 in green) in testis cords, surrounding cells, and tunica albuginea; [PC(38:7) + H]⁺ (m/z 804.5531 in dark blue) in interstitial tissue and cords in 11 DW testis. Lateral resolution = 10 µm, m/z window = 3 ppm, scale bars = 200 µm. PC = phosphatidylcholine. (D) Immunohistochemistry on adjacent testis sections using Leydig cell marker CYP11A1 (green) and Sertoli cell marker AMH (red) antibodies. Detection of 2-AG (m/z 379.2582 in red) (E) merged with [PC(38:7) + H]⁺ and [PC(32:0) + K]⁺ or (F) alone. Scale bar = 200 µm