Reference

Tryptophan and tonic immobility in chickens: effects of dietary and systemic manipulations

Tryptophan and tonic immobility in chickens: effects of dietary and systemic manipulations. Gallup, Gordon G., Jr.; Wallnau, Larry B.; Boren, James L.; Gagliardi, Gregg J.; Maser, Jack D.; Edson, Patricia H. (Dep. Psychol., State Univ. New York, Albany, N. Y., USA). J. Comp. Physiol. Psychol., 91(3), 642-8 (English) 1977. CODEN: JCPPAV. DOCUMENT TYPE: Journal CA Section: 18 (Animal Nutrition) Section cross-reference(s): 12 Consistent with a serotonergic-midbrain raphe model of tonic immobility, 4 expts. designed to effect changes in serum tryptophan [73-22-3], produced reliable effects on the duration of the response in chickens. Systemic injections of tryptophan, the dietary precursor to serotonin, led to a dose-dependent increase in immobility, with optimal effects being obsd. within 30 min after injection. Dietary depletion of endogenous tryptophan served to attenuate the duration of immobility, and a diet completely free of tryptophan but supplemented with niacin practically abolished the reaction. Dietary replacement served to reinstate the response. In a 5th expt., tryptamine [61-54-1], an alternative metabolic by-product of tryptophan, had no effect on immobility. The data are discussed in light of evidence showing serotenergic involvement in tonic immobility.

Studies on the action of biogenic amines on cockroach heart

Studies on the action of biogenic amines on cockroach heart. Collins, C.; Miller, T. (Dep. Entomol., Univ. California, Riverside, Calif., USA). J. Exp. Biol., 67, 1-15 (English) 1977. CODEN: JEBIAM. DOCUMENT TYPE: Journal CA Section: 2 (Hormone Pharmacology) Section cross-reference(s): 12 The whole abdominal heart of large nymphs or adult cockroaches responded to low concns. of acetylcholine (ACh) [51-84-3] or 5-hydroxytryptamine (I) [50-67-9] by increasing the rate of the heart beat. Prepns., which included 2-chamber sections of the abdominal heart, showed vastly decreased responses to ACh compared to the responses of the whole abdominal heart. Responses to I were similar in both prepns. Following assay with I, the cockroach heart beat often developed marked regularity. ACh assays produced such regularity only rarely. The sectioned cockroach heart prepn. was decreasingly responsive to I > synephrine [94-07-5] > octopamine [104-14-3] > tryptamine [61-54-1] > dopamine [51-61-6] > tyramine [51-67-2]. Dose-response curves revealed that the antagonist 501 c interacted competitively with I on the cockroach heart prepn. 501 C appeared to be a noncompetitive antagonist to octopamine, suggesting that I and octopamine act at sep. receptor sites on the myocardium. Expts. in which solns. of dibutyryl cyclic AMP [362-74-3], dibutyryl cyclic GMP [32266-35-6], or aminophylline were continuously perfused into the cockwoach heart, failed to establish that cyclic nucleotides mediate neurotransmitter or hormone action on this tissue.