Alpha-melanocyte-stimulating hormone (MSH) and [Nle4,D-Phe7]-alpha-MSH: effects on core temperature in rats.

The thermoregulatory effects of alpha-melanocyte stimulating hormone (MSH), its potent analog, [Nle4,D-Phe7]-alpha-MSH (NDP-MSH), and the 1-7, 4-10, and 7-13 amino acid fragments of NDP-MSH were examined by administering these substances to the anterior hypothalamic-preoptic area (AHPOA) of rats. In Experiments 1a (MSH) and 1b (NDP-MSH), animals received 0, 0.5, 1, 5, 10, or 50 pM peptide in 0.

Inhibitory action of alpha-melanocyte stimulating hormone on lordosis in rats: possible involvement of serotonin.

Alpha-melanocyte stimulating hormone (MSH) has been found to exert a short- and a long-term inhibitory action on lordosis. The present series of experiments examined the possibility that these effects are mediated by MSH-induced alterations in activity at serotonin type II receptors. In Experiment 1, quipazine (serotonin type II agonist) was found to significantly attenuate the short-term effect of MSH while only partially attenuating the long-term action of MSH.

Neonatal testosterone propionate treatment in the female gerbil: morphological and behavioral effects.

The present experiment examined the effects of a single neonatal injection of 1 mg or 100 micrograms of testosterone propionate (TP) on the sexual behavior and morphology of the female Mongolian gerbil. Four groups were created: vehicle-treated males (VM), 1-mg TP-treated females (HTP), 100-micrograms TP-treated females (LTP), and vehicle-treated females (VF). In adulthood, tests of sexual behavior were carried out after gonadectomy and appropriate hormone replacement therapy.

Short and long term inhibitory actions of alpha-melanocyte stimulating hormone on lordosis in rats.

The effects of 200 ng of intracerebroventricularly (ICV) and 20 micrograms of subcutaneously (SC) administered alpha-melanocyte stimulating hormone (MSH) on lordosis in rats were examined. Previous research, employing crossover designs, has revealed significant effects of MSH on lordosis. The results of Experiments 1a and 1b suggest that similar designs produce significant effects even in the absence of MSH.

Receptivity in Mongolian gerbils: dose and temporal parameters of ovarian hormone administration.

The dose and temporal effects of oestrogen and progesterone treatment on the induction of receptivity in female Mongolian gerbils were investigated. One group of animals was primed with 10 micrograms oestradiol benzoate (OB) 48 and 24 h prior to testing and received 500 micrograms progesterone (Pr) 0, 1, 2, 3, 6, 9, 12, 15, 18, 21 or 24 h prior to testing. These subjects were found to exhibit high levels of receptivity from hour 2 to hour 18.