A galenical of traditional Chinese herbal mixture (THC-002) reduces expression of tachykinin peptides within urethras of spontaneously hypertensive rats.

Aims: We investigated expression of tachykinin peptides neurokinin A, neurokinin B, and substance P within urethras of spontaneously hypertensive rats (SHRs) and determined if a traditional Chinese herbal mixture, THC-002, decreased them.

Methods: Ten- and 40-week-old male SHRs were randomly separated into three groups (n = 12 each). Rats of one group were given orally 20 ml 0.9% NaCl solution per kg body weight daily for 1 week. One hour later, each received a similar volume of water. Rats in the second group were also given saline. One hour later, each received 20 mg THC-002 per kg body weight. The third group was untreated. The urethras were removed and separated into prostatic and non-prostatic regions and analyzed by real-time reverse transcription polymerase chain reaction (n = 6) and immunohistochemistry (n = 6).

Results: In 40-week-old untreated SHRs, neurokinin B mRNA and protein, and substance P mRNA in prostatic urethras were significantly higher compared to the 10-week-old ones. Neurokinin A mRNA and protein, and substance P protein of the 40-week-old saline-loaded prostatic urethras were significantly higher compared to the 40-week-old untreated ones. In 40-week-old untreated SHRs, the non-prostatic urethral neurokinin B protein was significantly higher compared to the 10-week-old ones. In 40-week-old, saline-loaded SHRs, neurokinin A protein of the non-prostatic urethras was significantly higher compared to 40-week-old the untreated ones. In 40-week-old SHRs, THC-002 significantly decreased the expression of the urethral tachykinins, except for non-prostatic urethral neurokinin A mRNA.

Conclusions: Aging and saline-loading increased the expression of urethral tachykinin mRNAs and peptides. THC-002 partially decreased them.