Alzheimer's disease (AD) is the leading cause of senile dementia in today's society. Its debilitating symptoms are manifested by disturbances in many important brain functions, which are influenced by adenosine. Hence, adenosinergic system is considered as a potential therapeutic target in AD treatment. In the present study, we found that sodium hydrosulfide (NaHS, an H2S donor, 100 µM) attenua...

The apical membrane is an important site of mercury toxicity in shark rectal gland tubular cells. We compared the effects of mercury and other thiol-reacting agents on shark CFTR (sCFTR) and human CFTR (hCFTR) chloride channels using two-electrode voltage clamping of cRNA microinjected Xenopus laevis oocytes. Chloride conductance was stimulated by perfusing with 10 microM forskolin (FOR) and 1 ...

The possible role of type II (cGMP-stimulated cAMP hydrolysis) phosphodiesterase (PDE) in the accentuated antagonism of muscarinic effects on heart rate during beta-stimulation via endogenous nitric oxide (NO) was evaluated. The canine isolated sinoatrial node preparation was cross circulated with arterial blood of a support dog. The sinoatrial rate of the preparation was 96 +/- 5 beats/min (n ...

cAMP-raising agents with glucagon-like peptide-1 (GLP-1) as the first in class, exhibit multiple actions that are beneficial for the treatment of type 2 diabetic (T2D) patients, including improvement of glucose-induced insulin secretion (GIIS). To gain additional insight into the role of cAMP in the disturbed stimulus-secretion coupling within the diabetic β-cell, we examined more thoroughly th...

The aim of our study was to examine the effect of 3-isobutyl-1-methyl-xanthine (IBMX) and dibutyryl cyclic adenosine monophosphate (dbcAMP), stimulators of cAMP/protein kinase A-dependent intracellular signaling pathway, on reproductive function of gonadotropin-stimulated rabbit females. Ovarian cycle and ovulation in the control group were stimulated by PMSG (pregnant mare serum gonadotropin) ...

Cyclic nucleotide-gated (CNG) channels are a family of ion channels activated by the binding of cyclic nucleotides. Endogenous channels have been used to measure cyclic nucleotide signals in photoreceptor outer segments and olfactory cilia for decades. Here we have investigated the subcellular localization of cGMP signals by monitoring CNG channel activity in response to agonists that activate ...

RATIONALE We have shown recently that particulate (pGC) and soluble guanylyl (sGC) cyclases synthesize cGMP in different compartments in adult rat ventricular myocytes (ARVMs). OBJECTIVE We hypothesized that cGMP-dependent protein kinase (PKG) exerts a feedback control on cGMP concentration contributing to its intracellular compartmentation. METHODS AND RESULTS Global cGMP levels, cGMP-phos...

Rationale: We have shown recently that particulate (pGC) and soluble guanylyl (sGC) cyclases synthesize cGMP in different compartments in adult rat ventricular myocytes (ARVMs). Objective: We hypothesized that cGMP-dependent protein kinase (PKG) exerts a feedback control on cGMP concentration contributing to its intracellular compartmentation. Methods and Results: Global cGMP levels, cGMP-phosp...

The mechanisms by which neurotransmitters regulate neurite extension and growth cone motility have been extensively studied using identified Helisoma neurons regenerating in cell culture. Specific neurons, such as buccal neuron B19, display a complex response to the addition of 5-HT involving the generation of action potentials, influx of extracellular calcium, and cessation of neurite extensio...

We have used suction electrode recording together with rapid steps into 0.5 mM IBMX solution to investigate changes in guanylyl cyclase velocity produced by pigment bleaching in isolated cones of the salamander Ambystoma tigrinum. Both backgrounds and bleaches accelerate the time course of current increase during steps into IBMX. We interpret this as evidence that the velocity of the guanylyl c...