PACAP Modulates Acetylcholine-Elicited Contractions at Nicotinic Neuromuscular Contacts of the Land Snail.

In this study, we investigate the potentiating effect of PACAP27 on cholinergic neuromuscular transmission in the recently discovered flexor muscles of the land snail, Helix pomatia. Using immunohistochemistry, we show that PACAP and PAC1 receptors are present in nerve fibers innervating the flexor muscles but not in the muscle itself. We also observed that PACAP27 exerts both pre- and postsynaptic effects on the cholinergic synapse and performed tests using a broad spectrum of chemicals in order to explore the possible intracellular pathways through which PACAP mediates its stimulatory effect. Our pharmacological data demonstrate that PACAP27 presynaptically enhances the release of acetylcholine by activating the adenylate cyclase-cAMP-PKA pathway. Postsynaptically, PACAP27 was found to enhance muscle contractility by PKC-mediated signaling pathway resulting in an increased Ca(2+) release from intracellular stores. These findings suggest that regulation of Ca(2+) release may contribute to the stimulatory effect of PACAP. Our data are the first demonstration of the potentiating effect of PACAP27 at the molluscan excitatory neuromuscular contact.

Contraceptive efficacy of a combined oral contraceptive containing ethinyloestradiol 20 µg/drospirenone 3mg administered in a 24/4 regimen: a pooled analysis of four open-label studies.

OBJECTIVE: To determine the contraceptive efficacy of a low-dose combined oral contraceptive containing ethinyloestradiol (EE) 20 µg/drospirenone (drsp) 3mg administered for 24 days followed by a four-day hormone-free interval (24/4 regimen), by pooling data from four clinical trials. STUDY DESIGN: Data on the occurrence of pregnancy during treatment in four open-label trials that enrolled healthy female volunteers aged 17-36 years, who received EE 20 µg/drsp 3mg in a 24/4 regimen for 7 or 13 cycles, were pooled. RESULTS: Sixteen pregnancies occurred among 2386 women during 729,537 days (26,055 cycles) of treatment exposure, resulting in a Pearl Index (PI) of 0.80 (upper two-sided 95% confidence interval (CI) limit of 1.30). Of these pregnancies, seven were defined as method failures, resulting in an adjusted PI of 0.41 (upper two-sided 95% CI limit of 0.85), based on 616,607 days (22,022 cycles) of treatment. The Kaplan-Meier estimate for the one-year cumulative probability of contraceptive protection was 99.21%. CONCLUSIONS: The EE 20 µg/drsp 3mg combined oral contraceptive administered in a 24/4 regimen has acceptable contraceptive efficacy.

Pituitary adenylate cyclase activating polypeptide (PACAP) and its receptors are present and biochemically active in the central nervous system of the pond snail Lymnaea stagnalis.

PACAP is a highly conserved adenylate cyclase (AC) activating polypeptide, which, along with its receptors (PAC1-R, VPAC1, and VPAC2), is expressed in both vertebrate and invertebrate nervous systems. In vertebrates, PACAP has been shown to be involved in associative learning, but it is not known if it plays a similar role in invertebrates. To prepare the way for a detailed investigation into the possible role of PACAP and its receptors in a suitable invertebrate model of learning and memory, here, we undertook a study of their expression and biochemical role in the central nervous system of the pond snail Lymnaea stagnalis. Lymnaea is one of the best established invertebrate model systems to study the molecular mechanisms of learning and memory, including the role of cyclic AMP-activated signaling mechanisms, which crucially depend on the learning-induced activation of AC. However, there was no information available on the expression of PACAP and its receptors in sensory structures and central ganglia of the Lymnaea nervous system known to be involved in associative learning or whether or not PACAP can actually activate AC in these ganglia. Here, using matrix-assisted laser desorption ionization time of flight (MALDI-TOF) and immunohistochemistry, we established the presence of PACAP-like peptides in the cerebral ganglia and the lip region of Lymnaea. The MALDI-TOF data indicated an identity with mammalian PACAP-27 and the presence of a squid-like PACAP-38 highly homologous to vertebrate PACAP-38. We also showed that PACAP, VIP, and maxadilan stimulated the synthesis of cAMP in Lymnaea cerebral ganglion homogenates and that this effect was blocked by the appropriate general and selective PACAP receptor antagonists.

Efficacy and safety of a low-dose combined oral contraceptive containing drospirenone 3 mg and ethinylestradiol 20 mcg in a 24/4-day regimen.

OBJECTIVE: The study was conducted to assess the efficacy of a low-dose combined oral contraceptive (COC) containing drospirenone (drsp) 3 mg/ethinylestradiol (EE) 20 mcg administered for 24 days of active treatment followed by a 4-day hormone-free interval (24/4 regimen). STUDY DESIGN: In this open-label uncontrolled study conducted in 50 European centers, healthy females aged 18-35 years with a body mass index of less than 30 kg/m(2) received drsp 3 mg/EE 20 mcg 24/4 over 13 cycles. The primary efficacy variable was the number of unintended pregnancies. RESULTS: Five pregnancies occurred among 1101 women over 13,248 treatment cycles, resulting in a Pearl Index (PI) of 0.49 with an upper two-sided 95% CI limit of 1.14. Of these pregnancies, three were attributed to noncompliance with tablet use resulting in an adjusted PI for 'perfect use' of 0.22 (upper limit of two-sided 95% CI: 0.80) based on 11,755 cycles. CONCLUSION: Drospirenone 3 mg/EE 20 mcg 24/4 is a highly effective COC in nonobese women.

PACAP has anti-apoptotic effect in the salivary gland of an invertebrate species, Helix pomatia.

Pituitary adenylate cyclase activating polypeptide (PACAP) shows a remarkable sequence similarity among species and several studies provide evidence that the functions of PACAP have also been conserved among vertebrate species. Relatively little is known about its presence and functions in invertebrates. The aim of the present study was to investigate whether the well-known anti-apoptotic effect of PACAP can also be demonstrated in invertebrates. This effect was studied in the salivary gland of a molluscan species, Helix pomatia. In this work, we first showed the presence of PACAP-like immunoreactivity in the Helix salivary gland by means of immunohistochemistry. Radioimmunoassay measurements showed that PACAP38-like immunoreactivity dominated in the salivary gland of both active and inactive snails and its concentration was higher in active than in inactive animals in contrast to PACAP27-like immunoreactivity, which did not show activity-dependent changes. PACAP induced a significant elevation of cAMP level in salivary gland extracts. Application of apoptosis-inducing agents, dopamine and colchicine, led to a marked increase in the number of terminal uridine deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive apoptotic cells in the salivary gland, which was significantly attenuated by PACAP treatment. In a similar manner, the number of caspase-positive cells was reduced after co-application of dopamine and PACAP. Taken together, the data indicate that PACAP activates cAMP in a molluscan species and we show, for the first time, that PACAP is anti-apoptotic in the invertebrate Helix pomatia.