dironyl and Body-Weight

In adult rats, the partial D(2)-like agonist terguride acts as an antagonist at normosensitive D(2)-like post-synaptic receptors, while it acts as an agonist at the same receptors during states of low dopaminergic tone.. The purpose of the present study was to determine whether partial D(2)-like agonists exhibit both antagonistic and agonistic actions during the preweanling period.. In experiments 1 and 2 (examining the agonistic actions of terguride), preweanling rats were either given an escalating regimen of amphetamine to induce a state of amphetamine withdrawal or pretreated with the tyrosine hydroxylase inhibitor AMPT. Distance traveled was measured after rats were injected with saline, terguride (0.4-1.6 mg/kg), or the full D(2)-like receptor agonist NPA (0.01 mg/kg). In experiment 3 (examining the antagonistic actions of terguride), preweanling rats were pretreated with terguride 30 min before they were tested with saline, NPA (0.05 mg/kg), or amphetamine (1.5 mg/kg).. NPA had an exaggerated locomotor activating effect when tested under conditions of amphetamine withdrawal, while the partial D(2)-like agonist did not enhance distance traveled under any circumstance. Similarly, NPA increased and terguride did not affect the distance-traveled scores of AMPT-pretreated rats. In experiment 3, terguride pretreatment significantly reduced the distance traveled of amphetamine-treated and NPA-treated rats.. The behavioral evidence indicates that, during the preweanling period, terguride antagonizes D(2)-like post-synaptic receptors in a state of high dopaminergic tone; however, there is no evidence that terguride is capable of stimulating D(2)-like post-synaptic receptors during states of low dopaminergic tone.

Topics: Animals; Animals, Newborn; Apomorphine; Body Weight; Corpus Striatum; Dextroamphetamine; Dopamine; Dopamine Antagonists; Dopamine D2 Receptor Antagonists; Hyperkinesis; Lisuride; Methyltyrosines; Motor Activity; Rats; Rats, Sprague-Dawley; Receptors, Dopamine D2; Substance Withdrawal Syndrome; Tyrosine 3-Monooxygenase

Plasma prolactin was measured in genetically hypertensive obese Koletsky rats, in their lean siblings and in normotensive rats of Wistar strain. Lean as well as obese females show hyperprolactinemia. The males of Wistar strain as well as obese rats and their siblings show comparable prolactinemia except lean males which show higher level than Wistar males. Sex dependence of prolactinemia is missing in the rats of Wistar strain. Long lasting terguride treatment decreases prolactinemia in obese as well as lean rats of both sexes. The drug showed decreased prolactinemia in the males of Wistar strain. When the group of rats are considered in correlation computation positive correlation can be documented between total plasma cholesterol and plasma prolactin. In obese females positive correlation was found between plasma insulin and plasma prolactin.

Topics: Animals; Body Weight; Dopamine Agonists; Female; Hyperprolactinemia; Hypertension; Insulin; Lipids; Lisuride; Male; Obesity; Prolactin; Rats; Rats, Inbred SHR; Rats, Wistar

Glucose tolerance, insulin binding to erythrocytes, insulinaemia, plasma total cholesterol, plasma triglycerides, weight of fat pads, food consumption and body weight changes were studied in genetically hypertensive lean Koletsky rats. Long-term treatment with dopaminergic agonist terguride (0.2 mg/kg/day) normalized glucose tolerance and increased the percentage of bound insulin to erythrocytes in both sexes. Terguride decreased insulinaemia, cholesterolaemia, fat pads and body weight only in female rats. Food consumption was not influenced by terguride over the injection period.

Topics: Animals; Body Weight; Dopamine Agonists; Eating; Erythrocytes; Female; Glucose Tolerance Test; Hyperlipidemias; Insulin; Lisuride; Male; Rats; Rats, Inbred SHR

Glucose tolerance, total plasma cholesterol and plasma triglycerides were studied in the genetically hypertensive obese Koletsky rats (SHR/N-cp) and in their lean siblings. The initial part of the glucose tolerance curve was substantially elevated in both obese and lean Koletsky animals compared to normotensive Wistar rats. The abnormal glucose tolerance in hypertensive rats was accompanied by increased total plasma cholesterol and plasma triglycerides. Long-term treatment with dopaminergic agonists terguride or bromocriptine (0.2 and 2.0 mg/kg/day, respectively) exerted similar effects on lipid metabolism but both drugs differed in their influence on glucose tolerance. Terguride lowered plasma lipids and normalized glucose tolerance in both obese and lean Koletsky rats. Bromocriptine reduced hyperlipidaemia but did not attenuate the abnormalities of glucose tolerance in either lean or obese Koletsky animals.

Topics: Animals; Blood Pressure; Body Weight; Bromocriptine; Disease Models, Animal; Female; Glucose Intolerance; Hyperlipidemias; Hypertension; Insulin; Lipids; Lisuride; Male; Obesity; Rats; Rats, Inbred SHR; Rats, Sprague-Dawley; Rats, Wistar; Sex Factors

Topics: Administration, Oral; Animals; Body Weight; Drug Synergism; Ergolines; Female; Lactation; Lethal Dose 50; Lisuride; Oxytocin; Pregnancy; Prolactin; Urea