Endorphin analogs with potent and long-lasting analgesic effects

The influence of fragments of the LPH chains on learning, memory and attention in animals and man

“…Similarly, injections into the brain of ~, V, and fl-endorphin produced analgesia (Walker et aL, 1977b). Among these related molecules fl-endorphin is the most potent in producing analgesia.…”

[D-Ala2,(F5)Phe4]-dynorphin1–13-NH2 (DAFPHEDYN): A potent analog of dynorphin 1–13

“…r Analgesia Diuresis Opiate Naloxone Receptor UNEXPECTEDLY, intraventricular administration of dynorphin produced few notable opiate effects [14,16,28,31,33,35]. Such was the case for the enkephalins as well, probably in part because all these peptides exhibit rapid breakdown upon exposure to brain membranes [2, 7, 13, 16, 19-21, 23, 24, 30, 41].…”

“…[aH]-dynorphin, injected intracerebrally, is converted to SH-tyrosine and des-Tyrdynorphin with exceptional rapidity [41]. Therefore, most studies of the behavioral effects of intracerebral dynorphin may have actually been studies of potent nonopioid metabolite(s), especially des-Tyr-dynorphin [8,14,16,17,28,29,33,35,36]. One approach to inhibiting the metabolism of opioid peptides is the substitution of D-alanine in position 2 [3,4,27,32,34].…”

A solid state device for measuring sensitivity to thermal pain

“…Since the initial design (which has been improved upon several times) many compounds have been tested on a group of functionally identical devices. These include morphine [15], [Met]enkephalin, several enkephalin analogs [6,16], a-, y-, fl-endorphin and substituted analogs [17], dynorphin [18,19], vasopressin and vasopressin analogs [4,5]. ACTH, a-MSH and related substances [15,20], and a variety of cholinergic compounds [13].…”

“…Still, it has been argued that multiple tests of pain sensitivity should be employed before assuming that a particular drug has analgesic properties [12]. The tail-flick test has been used to gauge the potency of a variety of narcotic and non-narcotic agents [9,13,[15][16][17][18][19][20]. Hyperalgesia has also been observed [3] as well as analgesic effects from focal electrical brain stimulation [12] and various environmental or physiological [1] manipulations.…”