Abstract: OBJECTIVE: To observe the impact of Shijueming (Concha Haliotidis) on spontaneously hypertensive rats via blood pressure, serum calcium, vascular smooth muscle membrane L-type calcium channel α1 C subunit (CaL-α1C), plasma membrane calcium-ATPase (PMCA) mRNA expression, and the L-type calcium channel in vascular smooth muscle cells. METHODS:Twelve-week-old male rats with spontaneous hypertension were divided into three groups: a Shijueming (Concha Haliotidis) group (group 1), a nifedipine group (group 2), and a distilled water group (group 3). All were given a four-week treatment. Blood pressure and dissociative serum calcium were examined before treatment. Blood pressure was taken every week during treatment. Atomic absorption spectrometry was used to examine dissociative serum calcium. Re-verse transcription-polymerase chain reaction was used to examine the expression of CaL-α1C and PM-CA1 mRNA. The patch clamp technique was used to examine the electrophysiological characteristics of the vascular smooth muscle cell calcium channels. RESULTS: After treatment, blood pressure of the Shijueming (Concha Haliotidis) group lowered but not significantly (P>0.05). Blood pressure of the nifedipine group lowered significantly (P

Key words: Concha Haliotidis, Calcium channels, Rats, inbred SHR, Plasma membrane calcium-transporting ATPases