Contractility and pacemaker cells in the prostate gland.

PURPOSE: We focused on the current opinion on mechanisms generating stromal tone in the prostate gland. MATERIALS AND METHODS: We selected the guinea pig as the main species for investigation since its prostate has a high proportion of smooth muscle that undergoes age related changes similar in many respects to that in humans. The main techniques that we used were tension recording and electrophysiology. RESULTS: We previously reported distinct electrical activity and cell types in the prostate, and speculated on their functional roles. We believe that a specialized group of c-kit immunoreactive prostatic interstitial cells that lie between glandular epithelium and smooth muscle stroma have a role similar to that of gastrointestinal interstitial cells of Cajal, generating the pacemaker signal that manifests as slow wave activity and triggers contraction in smooth muscle cells in guinea pig prostates. CONCLUSIONS: Since changes in muscle tone are involved in the etiology of age dependent prostate specific conditions such as benign prostatic hyperplasia, knowledge of the electrical properties of the various prostatic cell types and their interactions with each other, with nerves and with the hormonal environment, and how these factors change with age is of considerable medical importance.

The use of popular movies during lectures to aid the teaching and learning of undergraduate pharmacology.

BACKGROUND: The role of the lecturer has changed to one where they must engage and motivate students to learn the subject material. AIMS: To investigate whether the use of short movie references to pharmacology during lectures could stimulate learning in undergraduate students. METHODS: One- to two-min film clips from popular movies containing a reference to the subject being covered were incorporated into Powerpoint presentations and shown at different times during pharmacology lectures. At the end of the lecture series, a student survey was conducted to assess the impact of the movies on student motivation, engagement and learning. RESULTS: Three positive effects were noted. First, students related theory to (simulated) practice by recognising that what they had learnt was actually being used. Second, students were motivated to attend lectures to see what clip would be used. Third, the clips provided a sectioning break, which helped to maintain the engagement of students throughout the lecture as well as the organisation of the lecture by the lecturer. CONCLUSIONS: The use of short popular movie references was a novel way to motivate and maintain the interest of large classes of undergraduate students throughout lectures.

Targeted disruption of the A2A adenosine receptor reduces in-vitro prostate contractility in mature mice.

Prostatic A2A adenosine receptors mediate varied effects. This study aimed to test whether genetic disruption of this receptor affects prostate contractility. Prostates taken from mice which were homozygous (A2AR-/-) and heterozygous (A2AR+/-) for the disrupted A2A adenosine receptor gene and wild-type littermates (A2AR +/+) were mounted in organ baths. Contractile responses to nerve stimulation and noradrenaline were measured in the presence of various pharmacological tools. Electrical field stimulation (0.5 ms pulse duration, 60 V, 0.1-20 Hz) yielded frequency-dependent contractions while exogenous administration of noradrenaline (10 nM-1 mM) or tyramine (1 microM-1 mM) produced concentration-dependent responses. Contractile responses to electrical field stimulation from A2AR-/- and A2AR+/- prostates were reduced when compared to A2A+/+ prostates (P=0.013, n=33-36). Prazosin (0.3 microM) inhibited electrical field stimulation-induced responses in prostates from A2AR+/+ and A2AR+/- mice (P< or =0.016, n=5-7) but not A2AR-/- mice (P=0.400, n=6). Tetrodotoxin abolished electrical field stimulation-induced responses in all prostates (P<0.001, n=5-7). NF 449 and ZM 241385 were without effect (P< or =0.421, n=4-6). There were no genotype differences in noradrenaline or tyramine concentration-response curves (P> or =0.180, n=10-13). Prazosin (0.3 microM) and cocaine (10 microM) attenuated the responses induced by noradrenaline (P<0.001, n=6-7) and tyramine (P<0.001, n=5-6), respectively, in all genotypes. Disruption of the A2A adenosine receptor leads to reduced nerve mediated contractile responses of the prostate in mature mice.