Long-term effects of streptozotocin-induced gestational diabetes mellitus on mechanical sensitivity and intraepidermal nerve fibers in female and male mice offspring.

While the long-term complications of gestational diabetes mellitus (GDM) in the cardiovascular, endocrine, and central nervous systems from offspring have been widely studied, less is known about the long-term outcomes of GDM on the peripheral nervous system. Thus, here we assessed the mechanical sensitivity and density of nerve fibers of the hind paw from middle-aged offspring born from dams with GDM. GDM was induced by the intraperitoneal administration of streptozotocin (STZ) in mouse dams. Mechanical sensitivity in male and female offspring was bi-weekly evaluated from week 18 to week 40 of age. At 40 weeks old, offspring were sacrificed and glabrous hind paw skin was processed for immunohistochemistry to determine the density of intraepidermal CGRP and PGP9.5 positive nerve fibers. Offspring mice born from STZ-treated dams had significantly greater mechanical sensitivity from 18 to 40 weeks of age compared to offspring born from vehicle-treated dams (control group). The density of intraepidermal CGRP+ and PGP9.5+ nerve fibers were significantly lower in the hind paw skin of female but not male offspring, born from STZ-treated dams versus the control group. These results suggest that GDM has long-term sex-dependent complications on the nociceptive system. Further studies are necessary to elucidate the mechanisms underlying the GDM-induced long-term consequences.