. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 210 L. CARIELLO ET AL. 200 150 1 100 50. -30 -10 log CONCENTRATION (mM) 00 FIGURE 1. Motility ofArbacia sperm suspended in ASW containing to mM metenkephalin. Abscissa: log cone, in mM. Ordinate: percent change in motility (control taken as 100%) after orientation at 120 X g. Symbols represent periods of preincubation before orientation. Solid circles, 0 min; open circles, 5 min; open triangles, 10 min; solid triangles, 15 min. opioid before centrifugal orientation. While the brief exposure of the "zero
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 210 L. CARIELLO ET AL. 200 150 1 100 50. -30 -10 log CONCENTRATION (mM) 00 FIGURE 1. Motility ofArbacia sperm suspended in ASW containing to mM metenkephalin. Abscissa: log cone, in mM. Ordinate: percent change in motility (control taken as 100%) after orientation at 120 X g. Symbols represent periods of preincubation before orientation. Solid circles, 0 min; open circles, 5 min; open triangles, 10 min; solid triangles, 15 min. opioid before centrifugal orientation. While the brief exposure of the "zero-time" cells during centrifugation elicited only about a 15% increase in progressive rate at that concentration, less than 5 micromoles per liter appeared to suffice as a threshold concentration for the metenkephalin preincubated for 15 minutes before alignment. Concentrations of the opioids greater than 1 mM/1 ASW were inhibitory (Fig. 1). The response to the opiate antagonist, (-)-naloxone, began to develop at about 25 micromolar while maximal stimulation occurred at millimolar and lesser in- creases in forward motility appeared at slightly higher concentrations, inhibition oc- curring at 2 millimolar and above (Fig. 2). Metenkephalin caused a doubling at its optimum while naloxone stimulated the sperm to a 75% increase over the control rate at its optimum when the sperm cells were preincubated for 15 minutes. Nearly complete inhibition with 15 minutes exposure occurred at about 1 millimolar metenkephalin but it required about 5 times that amount of (-)-naloxone to cause nearly complete cessation of movement. Since both metenkephalin and (anomalously), (-)-naloxone appeared to exert delayed stimulatory effects on the spermatozoa to somewhat different though over- lapping concentrations, it was important to test for interactive effects of the opioid and the so-called antagonist. This is illustrated in Figure 3, a composite of the graphs. Please note that these images
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
