Localization of Substance P-Immunoreactive Nerve Structures in the Rat Colon

The tachykinins, including their major representative substance P (SP), are an essential component of its non-adrenergic, non-cholinergic transmission the myenteric plexus enteric nervous system. Hence, understanding role that SP plays in conduction a wide variety motility and secretory reflexes lies evidence-based sites expression. In present study, presence, distribution staining intensity SP-positive nerve structures proximal distal colon adult rat have been investigated by means immunohistochemistry at light microscopic level. We observed abundance intensely stained beaded SP-immunopositive fibres, surrounding SP-immunonegative neuronal cell bodies basket-like manner. Fine bundles SP-immunostained varicose fibres were also registered adjacent smooth muscle layers. statistical analysis revealed discernible prevalence colon, compared to one. summary, our findings provide immunohistochemical evidence for occurrence abundant colonic region rat. Taken together with previous morphological pharmacological research results this study suggest SP-mediated neurotransmission is physiological likely pathological significance examined region.