Differential expression of neuropeptide Y Y1 receptors during pulpal inflammation.

Aim: To study the pattern of neuropeptide Y (NPY) Y1 receptor (Y1R) localization in the normal dental pulp and during different stages of pulpal inflammation. The hypothesis was that the expression of Y1R varies during different stages of pulpitis.

Methodology: Pulp exposure injury was made on first molar teeth of Sprague-Dawley rats.

Sympathectomy suppresses tumor growth and alters gene-expression profiles in rat tongue cancer.

Sympathetic nerves are known to affect carcinogenesis. Recently we found that sympathetic denervation decreases the size of rat tongue tumors. To identify genes involved in rat tongue carcinogenesis and to study the effect of sympathetic nerves on these genes, we compared gene-expression profiles in normal rat tongue (control) and in tumor-induced tongues with (SCGx) and without (Sham) bilateral sympathectomy.

High interstitial fluid pressure in rat tongue cancer is related to increased lymph vessel area, tumor size, invasiveness and decreased body weight.

Background: Interstitial fluid pressure (IFP) in most tumors is high, and this high pressure has been correlated with poor prognosis. Measurements of IFP in normal tongue and in tongue cancer are lacking. Recent research suggests the existence of a relationship between increased peritumoral lymph vessels (PTLV) and survival, and a correlation of increased lymphatic vessel density with an unfavorable prognosis has been reported.

Identification of a Ca2+-sensing receptor in rat trigeminal ganglia, sensory axons, and tooth dental pulp.

Extracellular Ca2+ regulates dentin formation, but little information is available on this regulatory mechanism. We have previously reported that sensory denervation reduces dentin formation, suggesting a role for sensory nerves in tooth mineralization. The G protein-coupled Ca2+-sensing receptor (CaR) is expressed in dorsal root ganglia and perivascular sensory nerves in mesenteric arterioles, and activation of these receptors by Ca2+ has been shown to induce vascular relaxation.

Sympathectomy decreases size and invasiveness of tongue cancer in rats.

The sympathetic nervous system plays a role in carcinogenesis wherein locally released sympathetic neurotransmitters affect proliferation, angiogenesis, vessel permeability, lymphocyte traffic and cytokine production. The present in vivo study was designed to investigate whether surgical sympathectomy, both unilateral and bilateral, had an effect on tumor growth, interstitial fluid pressure (IFP) and lymphatics in rat tongue cancer. We used 4-nitroquinoline-1-oxide (4-NQO) in drinking water for 19 weeks to induce tongue cancer in 20 Dark Agouti rats.