intranasal-administration-of-cns-therapeutics-to-awake-mice

Intranasal Administration of CNS Therapeutics to Awake Mice

Intranasal administration is a method of delivering  therapeutic agents to the central nervous system (CNS). It is  non-invasive and allows large ...

This study examined whether the larval pheromone employed by adult sea lamprey (Petromyzon marinus) to locate spawning streams and known to be at least partially comprised of bile acids is also employed by other lamprey species. Both production and release of lamprey-specific bile acids, and sensitivity to them were examined in a wide variety of species. High pressure liquid chromatography and electrospray ionization/mass spectrometry (ESI-MS) found gallbladders from 10 species of European and North American lamprey to contain large quantities of petromyzonol sulfate (PS) together with much smaller quantities of allocholic acid (ACA) and petromyzonol (P). Evaluation of holding waters from three of these species using ESI-MS found all to contain large quantities of PS and lesser quantities of ACA in similar ratios. Electro-olfactogram recording from the olfactory systems of three parasitic lamprey species found all to detect PS and ACA with high sensitivity. Behavioral studies using migratory adult sea lamprey found them to be attracted to the odors of heterospecific larvae as well as conspecific larvae, both of which contained similar amounts of PS and ACA. Finally, adult silver lampreys (Ichthyomyzon unicuspis) were also found to be attracted to the odor of larval sea lamprey. Together, these results demonstrate that PS and ACA are commonly produced and released by larval petromyzontid lampreys and likely used as part of a common evolutionarily conserved pheromone. This scenario is reasonable because lampreys share similar larval and spawning habitat requirements, and their larvae derive no apparent benefit from producing compounds that serve as an attractant for adults.

Evidence that petromyzontid lampreys employ a common migratory pheromone that is partially comprised of bile acids.

Adult sea lampreys locate spawning streams in the Great Lakes by using a migratory pheromone that is released by stream-resident larval conspecifics. Behavioral, electrophysiological, and biochemical analyses of larval release water have suggested that this pheromone is composed of several components, one of which is petromyzonol sulfate (PS), a known lamprey-specific bile acid. Its precursor, allocholic acid (ACA), has also been implicated. In this study, we employed high-performance liquid chromatography and mass spectrometry to look for both bile acids in various stream waters, thereby testing whether they might have a role in natural pheromone function. Although PS was measured at picomolar concentrations in streams known to contain larval lampreys and attract migratory adults, ACA was not. Neither compound was measured in streams lacking larvae. This finding indicates that PS is a component of the natural pheromone, and it suggests that ACA has little relevance.

Biologically relevant concentrations of petromyzonol sulfate, a component of the sea lamprey migratory pheromone, measured in stream water.

The sea lamprey is an ancient, parasitic fish that invaded the Great Lakes a century ago, where it triggered the collapse of many fisheries. Like many fishes, this species relies on chemical cues to mediate key aspects of its life, including migration and reproduction. Here we report the discovery of a multicomponent steroidal pheromone that is released by stream-dwelling larval lamprey and guides adults to spawning streams. We isolated three compounds with pheromonal activity (in submilligram quantities from 8,000 l of larval holding water) and deduced their structures. The most important compound contains an unprecedented 1-(3-aminopropyl)pyrrolidin-2-one subunit and is related to squalamine, an antibiotic produced by sharks. We verified its structure by chemical synthesis; it attracts adult lamprey at very low (subpicomolar) concentrations. The second component is another new sulfated steroid and the third is petromyzonol sulfate, a known lamprey-specific bile acid derivative. This mixture is the first migratory pheromone identified in a vertebrate and is being investigated for use in lamprey control.

Mixture of new sulfated steroids functions as a migratory pheromone in the sea lamprey.

The discovery of two new components of the migratory pheromone used by sea lamprey to guide adults to spawning grounds was recently reported. These hold promise for use in a pheromone-based control program for this species, an invasive pest in the Great Lakes. Details of the structure determination of these steroidal bis-sulfates [petromyzosterol disulfate (PSDS, 2) and petromyzonamine disulfate (PADS, 3)] are described here. Pattern matching of 1H NMR data was particularly valuable. This involved comparison of spectra of the natural samples of 2 and 3 with those of appropriate steroidal analogues [e.g., petromyzonol sulfate (PS, 1, a previously known sea lamprey bile acid derivative that is a third component of the migratory pheromone), cholesterol sulfate (6), and squalamine (8)] and model compounds containing the unprecedented aminolactam substructure present in 3. The logic underlying the iterative analyses used is presented.

Details of the structure determination of the sulfated steroids PSDS and PADS: new components of the sea lamprey (petromyzon marinus) migratory pheromone.

Many species of freshwater fish with relatively simple mating strategies release hormonally derived sex pheromones in urine. However, it is not known whether species with more complex reproductive strategies use specialized urinary chemical signals. We addressed this by using the Mozambique tilapia (Oreochromis mossambicus Peters 1852), a lek-breeding species in which males establish dominance hierarchies and visiting females mate preferentially with territorial/dominant males. We measured urination frequency of territorial males in social isolation and in the presence of females that were either ready to spawn or had finished spawning. In groups of fish, we monitored the volume of urine stored in subordinate and dominant males to determine if urine volume and olfactory potency (by recording electro-olfactograms, EOG, in females) are related to the male's social rank. Dominant, territorial males stored more urine than subordinates and released it in short pulses, the frequency of which increased in the presence of females ready to spawn but not in the presence of post-spawn females. Urine from subordinate and dominant males was fractionated by liquid chromatography and fractions tested for olfactory potency by using the EOG, with the most potent fraction analyzed by mass spectrometry (MS). The olfactory system of females was sensitive to a urinary compound that was more abundant in the urine of dominant males than in that of subordinates. MS analysis suggested the compound is a sulfated aminosterol-like compound with a formula of C29H40N2O10S. Therefore, we suggest that dominant/territorial tilapia males dramatically increase urination frequency in the presence of females ready to spawn and that the urinary odorant acts as a pheromonal signal of dominance, thereby influencing female spawning.

A sterol-like odorant in the urine of Mozambique tilapia males likely signals social dominance to females.

Migratory adult sea lampreys locate spawning streams by using a pheromone released by stream-resident conspecific larvae. It was recently reported that this pheromone is comprised of a mixture of three sulfated steroids: petromyzonamine disulfate (PADS), petromyzosterol disulfate (PSDS), and petromyzonol sulfate (PS). This manuscript reports in-depth details of pheromone isolation and provides new information on the olfactory potency of PADS and PSDS and the behavioral activity of synthesized PADS. Isolation was accomplished using bioassay-guided fractionation which included liquid chromatography-mass spectrometry, electro-olfactogram recording (EOG), and behavioral assays. Both highly purified and synthesized PADS stimulated the olfactory system of adult lamprey and were attractive at concentrations of 10(-13) M. PSDS also had olfactory activity at 10(-13) M. Cross-adaptation studies with EOG recording demonstrated that PADS, PSDS, and PS are detected by independent olfactory receptor sites. Finally, the mixture of all three components was as attractive as larval water to adult sea lampreys in laboratory mazes. It is believed that these steroids are the principal components of the pheromone.

Isolation and biological activity of the multi-component sea lamprey migratory pheromone.

Growth differentiation factor 5 (GDF5), in addition to its role in bone and joint development, protects dopaminergic (DA) neurons from degeneration, and is a potential therapeutic agent for Parkinson's disease. Its large size and insolubility at physiologic pH are obstacles for drug administration to the central nervous system (CNS) in humans.

Article	Year
Evidence that petromyzontid lampreys employ a common migratory pheromone that is partially comprised of bile acids. Journal of chemical ecology\| PubMed ID: 15672658	2004
Biologically relevant concentrations of petromyzonol sulfate, a component of the sea lamprey migratory pheromone, measured in stream water. Journal of chemical ecology\| PubMed ID: 16132221	2005
Mixture of new sulfated steroids functions as a migratory pheromone in the sea lamprey. Nature chemical biology\| PubMed ID: 16408070	2005
Details of the structure determination of the sulfated steroids PSDS and PADS: new components of the sea lamprey (petromyzon marinus) migratory pheromone. The Journal of organic chemistry\| PubMed ID: 17718505	2007
A sterol-like odorant in the urine of Mozambique tilapia males likely signals social dominance to females. Journal of chemical ecology\| PubMed ID: 18379847	2008
Isolation and biological activity of the multi-component sea lamprey migratory pheromone. Journal of chemical ecology\| PubMed ID: 18784958	2008
Intranasal delivery of growth differentiation factor 5 to the central nervous system. Drug delivery\| PubMed ID: 22353012	2012

Jared M. Fine

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