The PRBs indicated that from time-to-time there are unforeseen circumstances when wagering is cancelled just prior to or during a card, yet the races proceed. Even though the test inspectors are available, samples cannot be collected and analyzed as there has been no time to make arrangements or put in place processes that would permit them to collect and analyze these samples without prior written request and authorization. The CPMA agreed that advanced authorization is not needed under these circumstances. The PRBs will as soon as possible, provide verbal notice to the local Agency Officer and a written report of the circumstances to both the local Agency Officer and appropriate CPMA Regional Manager. The report will include the number of samples collected, the races from which the horses were selected for testing and the time of the announcement to cancel wagering. This report is necessary to verify collection provider invoices. The CPMA will then instruct the laboratory to analyze these samples. As in the case for the collection and analysis of samples for non-wagering races authorized in advance by the CPMA, the PRBs will pay the collection costs and the CPMA will pay for the analysis costs.
D-Aspartic acid (D-Asp) and nitric oxide (NO) are two biologically active molecules playing important functions as neurotransmitters and neuromodulators of nerve impulse and as regulators of hormone production by endocrine organs. We studied the occurrence of D-Asp and NO as well as their effects on testosterone synthesis in the testis of boar. This model was chosen for our investigations because it contains more Leydig cells than other mammals. Indirect immunofluorescence applied to cryostat sections was used to evaluate the co-localization of D-Asp and of the enzyme nitric oxide synthase (NOS) in the same Leydig cells. D-Asp and NOS often co-existed in the same Leydig cells and were found, separately, in many other testicular cytotypes. D-Asp level was dosed by an enzymatic method performed on boar testis extracts and was 40+/- nmol/g of fresh tissue. NO measurement was carried out using a biochemical method by NOS activity determination and expressed as quantity of nitrites produced: it was +/- nmol/mg of tissue. The effects of the two molecules on steroid hormone production were evaluated by incubating testis homogenates, respectively with or without D-Asp and/or the NO-donor L-arginine (L-Arg). After incubation, the testosterone presence was measured by immunoenzymatic assay (EIA). These in vitro experiments showed that the addition of D-Asp to incubated testicular homogenates significantly increased testosterone concentration, whereas the addition of L-Arg decreased the hormone production. Moreover, the inclusion of L-Arg to an incubation medium of testicular homogenates with added D-Asp, completely inhibited the stimulating effects of this enantiomer. Our results suggest an autocrine action of both D-Asp and NO on the steroidogenetic activity of the Leydig cell.