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oai:www.ideals.illinois.edu:2142/71428 2023-07-11 col_2142_5131 col_2142_16508 com_2142_5130 com_2142_16507 com_2142_14793 com_2142_8903

164 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1983. http://hdl.handle.net/2142/71428 (UMI)AAI8410030 Rezvani-Bidgoli, Amir Hosein 2014-12-16T06:45:44Z 2014-12-16T06:45:44Z 10000-01-01 1983 1983 Certain neuropeptides alter the thermoregulatory responses and behaviors of the animals by affecting the preoptic/anterior hypothalamus (PO/AH). The primary objective of this investigation is to study the effect of beta-endorphin ((beta)-E) on regulation of body temperature. Male New Zealand White rabbits, Oryctolagus cuniculus, were stereotaxically implanted with a guide tube above the PO/AH for the injection of (beta)-E, naloxone, sodium salicylate, or physiological saline. PO/AH and ear temperature, oxygen consumption, and evaporative heat loss (EHL) were recorded before and after injection of first saline and then (beta)-E, naloxone, or sodium salicylate at ambient temperatures (T(,a)) of 2-31(DEGREES)C. A 5-(mu)g injection of (beta)-E promoted a rapid reduction in ear temperature followed by a prolonged rise in PO/AH (body) temperature (T(,br)). Preinjection with an isovolumetric amount of naloxone, inhibited the thermoregulatory effects of (beta)-E. The (beta)-E- induced rise in body temperature was directly correlated with T(,a). (beta)-E had no effect on oxygen consumption. (beta)-E inhibited EHL at T(,a)'s of 27 and 31 but not at 5(DEGREES)C. The (beta)-E-induced rise in body temperature was not antagonized by preinjection of sodium salicylate. In another series of experiments, T(,ear) and T(,br) were recorded in control and (beta)-E pretreated rabbits while radiant heat was applied to the dorsal skin. In control the T(,ear) underwent a rapid increase during back heating. Following (beta)-E administration there was a large reduction in responsiveness of T(,ear) to radiant heat. The time to respond to radiant heat for (beta)-E pretreated rabbits was significantly longer than that for control rabbits. The interaction between norepinephrine (NE) and (beta)-E in regulation of body temperature was examined. The data indicate that (beta)-E-hyperthermia and NE-hyperthermia are mediated through separate pathways. The thermal response to a range of doses of (beta)-endorphin produced a linear dose-response curve. In conclusion, (beta)-E microinjected into the rabbit induces a reduction in passage of temperature information from cutaneous thermal receptors to the PO/AH and the (beta)-E-induced reduction in sensitivity of the vasomotor system to radiant heat may account for the effectiveness of this opioid peptide in promoting hyperthermia in the rabbit. The (beta)-endorphinergic system may have a natural role in thermoregulatory responses during physical and psychological stress. Made available in DSpace on 2014-12-16T06:45:44Z (GMT). No. of bitstreams: 1 8410030.pdf: 5001839 bytes, checksum: bed24900d825f601b1cd32346f5f711e (MD5) Previous issue date: 1983 Embargo set by: Seth Robbins for item 71594 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only Biology, Animal Physiology Involvement of Beta-Endorphin in Thermoregulation of Rabbits, Oryctolagus Cuniculus text Physiology and Biophysics Physiology University of Illinois at Urbana-Champaign Dissertation Ph.D.