Effects of the nonagouti pelage-color allele on the behavior of captive wild Norway rats (Rattus norvegicus).

The objective of the present study was to determine the extent to which the nonagouti pelage-color allele influences selected behaviors (including docility) of the wild Norway rat. Agouti and nonagouti (black) littermates were compared in tests for handling, open-field behavior, platform jumping, and response to a novel food item, all of which clearly differentiate wild and domestic rats. Nonagouti rats were significantly easier to approach, capture, and handle than their agouti sibs. However, differences between agouti and nonagouti rats for the other variables studied were not significant. Although the presence of the nonagouti allele cannot fully account for the behavioral differences between wild and domestic Norway rats, it may have facilitated the domestication of this species by improving ease of handling.

Infertility: the emotional aspects.

It may be that many health care professionals lack insight into the emotional needs of the infertile. In this article, Chérie Cottle addresses the psychological responses to infertility, which bear striking resemblances to the expected sequelae of bereavement. The role of the nurse in encouraging and assisting couples to acknowledge and accept their infertility is described with an emphasis on the need for a more sympathetic approach to such clients.

Glycine-directed peptide amidation: presence in rat brain of two enzymes that convert p-Glu-His-Pro-Gly-OH into p-Glu-His-Pro-NH2 (thyrotropin-releasing hormone).

To study the possibility of glycine-directed amidation in rat brain, we synthesized the substrate p-Glu-His-Pro-Gly-OH. Adult and neonatal rat brain and adult rat pituitary were sonicated, frozen and thawed, and fractionated by gel permeation chromatography, and fractions from each tissue were assayed for enzymatic activity capable of converting this model substrate into thyrotropin-releasing hormone. We report the presence in rat brain and rat pituitary of two enzymes catalyzing conversion of p-Glu-His-Pro-Gly-OH into thyrotropin-releasing hormone. Based on the differing chemical and physical properties of these two enzymes and their differing affinities for a number of p-Glu-His-Pro-aa-OH analogs (in which aa = glycine, beta-alanine, gamma-butyric acid, and delta-aminovaleric acid), we conclude that there are two distinct enzymatic processes for the terminal amidation of peptides in brain and that COOH-terminal extensions other than glycine are capable of directing COOH-terminal amidation.