Effect of central administration of the kappa-opiate receptor agonist U 69.593 on neurohypophyseal hormone levels in blood and cerebrospinal fluid.

Intracerebroventricular (i.c.v.

The role of limbic vasopressin and oxytocin in social recognition.

Young male rats were exposed two times for 5 min, to older male rats with an interval of 30 min in the anti-vasopressin serum experiments and with an interval of 120 min in the anti-oxytocin serum experiments. The time spent by the older rats with social investigation of the younger animal was scored during the two encounters. In placebo-treated animals the time spent on social investigation of the younger animal during the second encounter at 30 min is significantly shorter than during the first one (social recognition).

Dynorphin-A and vasopressin release in the rat: a structure-activity study.

The effects on vasopressin (VP) release of three dynorphin-A fragments and two antidynorphin antisera were tested in vivo and in vitro. In vivo, the order of potency to inhibit VP release 30 min upon i.c.

Neuromedin-induced excessive grooming/scratching behavior is suppressed by naloxone, neurotensin and a dopamine D1 receptor antagonist.

Neuromedin B and neuromedin C were tested for their grooming/scratching-inducing effects and the composition of neuromedin-induced grooming was established by calculating the relative contribution of various grooming elements to the total grooming scores. Excessive grooming induced by neuromedins is characterized by a predominant display of scratching. Since neuromedin C is much more potent than neuromedin B to induce excessive grooming/scratching behavior, it is concluded that the carboxyl-terminal heptapeptide of neuromedin C is important for this effect.

Pharmacological assessment of the site of action of opioids on the release of vasopressin and oxytocin in the rat.

Naloxone and its congener, methyl naloxone, were given subcutaneously (s.c.) or centrally (i.