Comparative studies on the effects of some enkephalin agonists on the ERG of frog and turtle.
1. Effects of mu-agonist morphine in a concentration of 1.10(-5)-1.10(-6) M and delta-agonist Dalargin in a concentration of 1.10(-5)-1.10(-8) M on electroretinogram (ERG) of frog (mixed type of retina) and turtle (predominantly cone retina) were investigated. 2. The enkephalin agonists studied influenced both types of retina in a different manner, producing mainly inhibitory effects. 3. Variability in mu-receptors sensitivity in the turtle retina, most probably depending on the seasons, was observed. 4. The data obtained show that opiate-sensitive mechanisms control the bioelectric activity of the distal layers of frog and turtle retina. 5. Species specificity and variability in sensitivity of the opiate receptors are discussed.
Vitanova
L
L
Medical Academy, Sofia, Bulgaria.
Popova
E
E
Kupenova
P
P
Kosteljanetz
N
N
Belcheva
S
S
D000818:Animals; D004596:Electroretinography / Q000187:drug effects*; D016308:Enkephalin, Leucine-2-Alanine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004745:Enkephalins / Q000502:physiology; D066298:In Vitro Techniques; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology*; D011895:Rana ridibunda; D011957:Receptors, Opioid / Q000187:drug effects / Q000502:physiology; D012160:Retina / Q000187:drug effects / Q000502:physiology*; D013565:Sympatholytics / Q000494:pharmacology; D014426:Turtles
D004745:Enkephalins; D011957:Receptors, Opioid; D013565:Sympatholytics; D009270:Naloxone; D016308:Enkephalin, Leucine-2-Alanine; D009020:Morphine; C040996:enkephalin-Leu, Ala(2)-Arg(6)-