We present the first identification of spinal afferent endings in the urethra. Peptidergic nerve fibers, including multiple populations of spinal afferents, provide rich innervation of the female mouse urethra. The morphology of fibers in the epithelium and other regions suggests multiple nerve-cell interactions impacting on urethral function.

Vulvodynia is a prevalent chronic pain disorder associated with high medical costs and often ineffective treatments. The major pathological feature is proliferation of vaginal nerve fibers. This study aimed to develop a highly reproducible animal model to study neuroproliferation in the vagina and aid the identification of appropriately targeted treatments for conditions such as vulvodynia. Mild chronic inflammation was induced using microinjection of complete Freund's adjuvant in the distal vagina of C57Bl/6 mice. Control mice received saline. Inflammation and innervation density were assessed at 7 and 28 days after a single administration or 14 days following repeated administration of complete Freund's adjuvant or saline. Histochemistry and blinded-analysis of images were used to assess vaginal morphology (H & E) and abundance of macrophages (CD68-labeling), mast cells (toluidine blue staining, mast cell tryptase-immunoreactivity), blood vessels (αSMA-immunoreactivity) and nerve fibers immunoreactive for the pan-neuronal marker PGP9.5. Subpopulations of nerve fibers were identified using immunoreactivity for calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY). Single administration of complete Freund's adjuvant resulted in vaginal swelling, macrophage infiltration, vascular proliferation and increased abundance of nerve fibers immunoreactive for CGRP, SP, VIP and/or PGP9.5 but not NPY, evident at seven days. Inflammation further increased following repeated administration of complete Freund's adjuvant but nerve fiber proliferation did not. Nerve fiber proliferation continued to be evident at 28 days. The inter-individual differences within each treatment group were small, indicating that this model may be useful to study mechanisms underlying vaginal nerve fiber proliferation associated with inflammation.

Summary An allergic reaction, occurring in a patient who has been put on monocomponent insulin for the first time, is extremely rare. A case of primary allergy to monocomponent porcine insulin, and its subsequent management, is described here.