Urogenital paraneurons in several mammals.

The researchers studied cells that produce certain chemical substances, called paraneurons, in the urogenital tract of humans and various animals. These cells, found in specific parts of this tract, produce substances such as serotonin and somatostatin, which may play key roles in regulating the urinary and sperm flow.

Research Methodology

• The researchers used multiple techniques to demonstrate the presence of paraneurons in the urogenital tracts of several mammals.
• These techniques include histochemical, immunohistochemical, immunofluorescent and double labelling immunofluorescent methods.
• These methods allowed the researchers to identify cells that produce amines or peptides – signaling chemicals in the bodies of these mammals that interact with neurons.

Findings

• Paraneurons were found in the urethro-prostatic complex in humans, rabbits, buffalo, and sheep. These cells also existed in the uterine horns (the part of the uterus extending to the ovaries) of pigs, horses, and mice.
• Within the urethro-prostatic complex of sheep, cells were found to produce serotonin, chromogranin A and somatostatin.
• In many cases, the signalling substance and the “marker”-protein were found in the same cells.
• Chromogranin A and somatostatin-containing cells were found in the uterine horns of pigs.

Implications and Hypotheses

• The research suggested that serotonin could play a key role in controlling the muscle function in the male urogenital tract. This process may regulate the flow of urine and sperm.
• The function of somatostatin cells within the urogenital tract was not defined as part of this study. The researchers hypothesized these cells could have a dual endocrine/paracrine action. This possibility means that such cells might function in both hormone secretion (endocrine) and local action on adjacent cells (paracrine).
• The evidence for this hypothesis was the direction and presence of their cytoplasmic processes – the pathways inside a cell that allow for the transportation of substances.